http://www.next.gr/templates/cleancss/img/feed-esyndicat.pnghttp://www.next.gr/http://www.next.gr/oscillators/Varius-Circuits/http://www.next.gr/oscillators/Varius-Circuits/Multiplying-pulse-widths-circuit-l12080.htmlA circuit for multiplying the width of incoming pulses by a factor greater or less than unity is simple to build and has the feature that the multiplying factor can be selected by adjusting one potentiometer only. The multiplying factor is determined by setting the potentiometer in the feedback of a 741 amplifier. The input pulses of width r and repetition period is used to trigger a sawtooth generator at its rising edges to produce the waveform e2 having a peak value of (E) volt. Wed, 27 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Discrete-sequence-oscillator-l13537.htmlThe swept-frequency oscillator offers an inexpensive source of discrete frequencies for use in testing digital circuits. In this configuration, the circuit generates an 80-second seguence of eight frequencies, dwelling for 10 seconds on each frequency. You can change the dwell time or the number of frequencies. Frequencies can range from 0.005 Hz to 1 MHz. The programmable crystal oscillators, PXOs, IC2 and IC4 can each generate 57 frequencies in response to an 8-bit external code. Tue, 26 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Precise-wave-generator-l12089.htmlThe positive and negative peak amplitude is controllable to an accuracy of about ± 0.01 V by a dc input. Also, the output frequency and symmetry are easily adjustable. The oscillator consists of an integrator and two comparators—one comparator sets the positive peak and the other the negative peak of the triangle wave. If R1 is replaced by a potentiometer, the frequency can be varied over at least a 10 to 1 range without affecting amplitude. Symmetry is also adjustable by connecting a 50 kfi resistor from the inverting input of the LM118 to the arm of the 1 kO potentiometer. Mon, 25 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Stable-Start-Stop-Oscillator-l14333.html Oscillators that generate a predetermined number of pulses are often required in applications such as video wo Mon, 25 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Improved-Cmos-Multivibrator-Circuit-l14835.html This circuit uses a protective resistor R2 in conjunction with feedback resistor Rl. Together, they form a voltage divider to reduce the input voltage amplitude for ICl-a so that the protective diodes never conduct. Mon, 25 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-Generator-With-Lt1016-Circuit-l14684.html This function generator, based on an LT1016 high-speed comparator, will generate from a single +5-V supply. Thu, 14 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Non-integer-programmable-pulse-divider-l12294.htmlIn applications where the period of the input pulses is uneven and the divider is required to cover a wide range of frequencies, the non-integer programmable pulse divider shown can be used. The purpose of the D-type flip-flop (IC2) is to synchronize the input signal with the clock pulse. When the clock pulse changes from low to high and the input is high, IC2 output goes high. Subsequently, IC3 resets to zero and starts counting up. Wed, 13 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/S-R-Flip-Flop-l14509.html This circuit combines the characteristics of an asynchronous S/R flip-flop and an edge-triggered JK flip-flop. It changes sta Mon, 11 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Rf-genie-l12215.htmlA variable oscillator covers 3.2 to 22 MHz in two bands—providing coverage of 80 through 15 meters plus most crystal-filter frequencies. Optional 455 kHz and 10.7 MHz crystal oscillators can be switched on-line for precise if alignment. Generator output is on the order of 4 volts p-p into a 500 ohm load. Sat, 09 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Simple-Rf-Test-Oscillator-Circuit-l14867.html A simple oscillator for IF alignment (455 kHz) can prove useful in field testing or where a standard signal generator is available. Fri, 08 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Code-practice-oscillator-l12472.htmlThis simple cpo uses the 7404 low-power Schottky hex inverter. C is a 5- to 30-µf electrolytic selected for the desired pitch Wed, 06 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Digitally-controlled-oscillator-l13094.htmlThe microprocessor-controlled oscillator has a 8159 to 1 frequency range covering 2 Hz to 20 kHz. An exponential, current output IC DAC functioning as a programmable current source alternately charges and discharges a capacitor between precisely-controlled upper and lower limits Tue, 05 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Clock-source-l13095.htmlA clock source using LM311 voltage comparator in positive feedback mode Thu, 28 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Variable-audio-oscillator-20hz-to-20Khz-l13093.htmlTo obtain a 1000:1 Sweep Range, the voltage across external resistors Ra and Rb must decrease to nearly zero. This requires that the highest voltage on control pin 8 exceed the voltage at the top of Ra and Rb by a few hundred millivolts. The circuit achieves this by using a diode to lower the effective supply voltage on the 8038 Mon, 25 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Single-chip-frequency-doubler-l13325.htmlThe frequency doubler uses only one !C. Like other doublers, this circuit uses both the rising and falling edges of the input signals to produce digital pulses, thus effectively doubling the input"s frequency. Without the rc networks at IC1 inputs, IC1 would not produce any output pulses. However, the rc networks delay one edge with respect to the other. The A input lags the B input for positive-going edges, and the B input lags the A input for negative-going ones. Wed, 20 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/5-V-oscillator-l13555.htmlConsistently self-starting and yet capable of operating from over 1 Hz to 10 MHz, this low-cost oscillator requires only five components. Sun, 17 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/One-chip-audio-generator-l12336.htmlThis high-quality low-cost generator covers 20 Hz to 20 kHz in three bands with less than 1% distortion. LM1-10 V, 14 mA (344,1869, 914) or 10 V, 10 mA (913, 367). Sat, 16 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Single-supply-multivibrator-l13342.htmlThis multivibrator uses a CA3420 BiMOS op amp to provide improved frequency stability. The output frequency remains essentially independent of supply voltage. Because of the inherent buffering action of pin 6, Tue, 12 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-Generator-With-Variable-Duty-Cycle-Circuit-l14959.html Using only one IC and six passive components, this pulse generator has a frequency range of 400 to 4000 Hz and an adjustable duty cycle of 1 to 99%. A threshold detector (ICA) and an integrator (ICB) generate a triangular waveform. A positive voltage at the output of ICA causes the output of ICB to become a negative-going ramp. When the output of this ramp reaches a certain value, ICA, by virtue of its positive-feedback network, changes state; its output becomes negative, and the integrator generates positive ramp. This process continually repeats. A voltage follower (ICC) and a 100-kn potentiometer provide a variable 0.18-V reference voltage. Tue, 12 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/50Khz-oscillator-l13092.htmlA 50 kHz circuit is possible because of the more nearly ideal characteristics. Mon, 11 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Frequency-doubler-l13321.htmlThe output contains the sum component, which is twice the frequency of the input, Sat, 09 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Gated-1Khz-Oscillator-Normally-On-Circuit-l14870.html This gated 1-kHz oscillator offers press-to-turn-off operation, A, Mon, 04 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-frequency-multivibrator-l13350.htmlThis circuit uses half the CA3290 BiMOS dual voltage comparator as conventional multivibrator. The second half maintains frequency against effects of output loading. Sat, 02 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Tone-burst-oscillator-and-decoder-l13090.htmlA tone burst sent at the beginning of each transmission is decoded (at receiver) by a PLL causing output from pin 3 Thu, 31 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-generator-l13349.htmlThis generator will supply sine, triangular, and square waves from 2Hz to 20kHz. This complete test instrument can be plugged into a standard 110 Vac line for power. VoVT will be up to ±25 V (50 V pk-pk across loads as small as 10 0 (about 2.5 A maximum output current). Capacitor working voltages should be greater than 50 V de and all resistors should be 112 W, unless otherwise indicated. Wed, 30 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Adjustable-oscillator-l12218.htmlIn this circuit, there are two feedback paths around an op-amp. One is positive dc feedback which forms a Schmitt trigger. The other is a CR timing network. Imagine that the output voltage is +10 V. The voltage at the noninverting terminal is +15 V. The voltage at the inverting terminal is a rising voltage with a time constant of CTRT. When this voltage exceeds + 5 V, the op amp's output will go low and the Schmitt trigger action will make it snap into its negative state. Tue, 29 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Tone-generator-l12338.htmlThe circuit uses a pair of 555 timers or a single dual timer. Capacitor Cl controls the speed of the warble, while C2 determines the pitch. Mon, 28 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Hcu-hct-based-oscillator-l13543.htmlWhen frequency stability is not of prime importance, a simple, yet reliable, digital clock oscillator can be made with the aid of relatively few components. High-speed CMOS (HCU/HCf) inverters or gates with an inverter function are eminently suitable to make such oscillators, thanks to their low power consumption, good output signal definition, and extensive frequency range. The circuit as shown uses two inverters in a 74HCf04 or 74HCU04. Sun, 27 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Precision-Lf-Oscillator-Circuit-l14871.html Using Rl, R7, and D1 to preset CI to one third of the supply voltage, Sun, 27 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Divide-circuit-l13323.htmlAn input signal drives both SN74 74 D-type flip-flops, which are positive edge-triggered devices. A low-to-high input signal transition triggers tbe A flip-flop, while a high-to-low input signal transition triggers the B flip-flop via tbe SN7404 inverter. Either flip-flop in tbe high state will cause the output to decrease via the SN7402 NOR gate. This in turn disables the opposite flip-flop from going to tbe high state. The flipflop in the high state remains there for one clock period, then it is clocked low. Witb both flip-flops low, the output increases, enabling the opposite flip-flop to be clocked high one-half clock cycle later. Sat, 26 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-Generator-Circuit-l14685.html A quad op amp makes up the heart of this function generator. Ul-a generates a square wave, and outputs this to J8. J1 and J2 are pulse outputs obtained by differentiating the square wave. Integrator Ul-b generates a triangle-wave shaper to obtain a sine wave. Sat, 19 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Signal-injector-l13691.htmlThis unit is a single oscillator built around an LF351 JFET-input op amp. Resistors Rl and R2 bias the noninverting input while R3 biases the inverting input from the output. This layout provides lOO% negative feedback, but the decoupling caused by C2 gives reduced feedback and high-voltage gain when dealing with audio frequencies. The fundamental operatiog frequency is about 800 Hz. Potentiometer R4 is the output-level control. Th use it start at the speaker. Fri, 18 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Gated-1Khz-Oscillator-Normally-Off-Circuit-l14869.html This gated 1-kHz oscillator offers press-to-turn-on operation, A, Fri, 18 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Oscillator-produces-audio-sinusoids-l12333.htmlBy placing a tuned circuit in the UJT oscillator's current-pulse path, a 3750-Hz sinusoid can be created at B2 with the component values shown. Thu, 17 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Butler-common-base-oscillator-l12632.htmlThis circuit operates at or near series resonance Tue, 15 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Wide-range-oscillator-l13542.htmlThe gain control allows the oscillator to maintain essentially constant output over its range. Sat, 12 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Free-running-multivibrator-l13348.htmlThis is the simplest of any programmable oscil lator circuit, since only one stable timing capacitor is required. The output square wave is about 25 V pk-pk, and bas rise and fall times of about 0.5 p,s. Wed, 09 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Half-duty-cycle-oscillator-l13544.htmlFrequency of oscillation depends on the Rl/Cl time constant and allows frequency adjustment Tue, 08 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-generator-l13330.htmlThis circuit can output sine, square, and triangular signals of from 15 Hz to 25 kHz in three ranges. The circuit is built around an 8038 function generator that produces the triangular-and square-wave outputs directly from an oscillator. The triangular output is then processed to develop the sine wave. While that method doesn"t provide a sufficiently low level of distortion to let you make distortion measurements on audio gear, the degree of purity is high enough for frequency-response tests and a lot of other audio analysis. Mon, 07 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Butler-emitter-follower-oscillator-100Mhz-l12629.htmlThis circuit has good performance without amplifier has a gain of only one with built-in any parasitics because emitter follower negative feedback Sun, 06 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Staircase-generator-l13725.htmlThis circuit is a high-input impedance version of the so-called diode pump or staircase generator. Note that charge transfer takes place at the negative-going edge of the input signal. The most common application for staircase generators is in low-cost counters. Sun, 06 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/RC-audio-oscillator-with-555-l12334.htmlTransistor Q5 and the 1000 ohm resistor form the variable element needed for controlling the frequency of VCO by limiting the charging current flowing into the 0.15 timing capacitor according to the forward bias being applied to Q5. As the voltage on pins 2 and 6 of Ul reach 2A Vcc (about 6 volts with a 9-volt supply) the timer will fire and pin 3 will be pulled low. Pin 7, an open collector output, goes low and begins to discharge the timing capacitor—through the 3.3 kilohm resistor. Sat, 05 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Adjustable-Vfo-Temperature-Compensator-Circuit-l14879.html Use of a differential capacitor allows temperature compensation of LC circuit using an NFO and N1500 ceramic. C6 is a differential capacitor that has two stators and one common rotor. When one capacitance (stator) is maximum, the other is minimum. Sat, 05 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/RC-oscillator-l12082.htmlThe circuit covers 15 Hz-30 kHz and is useful as a function generator. Fri, 04 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Xor-gate-complementary-signals-generator-l13334.htmlSome applications, such as driving three-state buffers for data multiplexers or for biphase clocks in high-speed systems, require complementary signals having a small-time skew and nearly simultaneous transitions. Here, XOR gates function as both inverting and noninverting gates. For CMOS systems, practically any type of XOR gate will work. Sun, 23 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Cmos-oscillator-l13550.htmlThis circuit is guaranteed to oscillate at a frequency of about 2.2/(R1 x C) ifR2 is greater than R 1. Sun, 23 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Single-control-function-generator-l13351.htmlThis function generator, with an adjustment range in excess of 1,000,000 to 1, uses a CA3160 BiMOS op amp as a voltage follower, a CA3080 OTA as a high-speed comparator, and a CA3080 as a programmable- current source. Three variable capacitors, C1, C2, and C3 shape the triangular signal between 500 kH and 1 MHz. Mon, 17 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Rlc-oscillator-l13539.htmlA positive transient, such as the power switch closing, charges r through L to a voltage above the supply voltage, if Q is sufficient. When the current reverses, the diode blocks and triggers the SCS. As the capacitor discharges, the anode gate approaches ground potential, depriving the anode of holding current. Mon, 17 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/A-sine-cosine-generator-l12077.htmlThe scheme presented delivers waveforms from any function generator producing a triangular output and a synchronized TTL square wave. A1 and A2 act as a two-phase current fectifier by inverting the negative voltage appearing at the input of Al. Positive input: Both Al and A2 work as unity gain followers,D1 and D2 being in the off-state. Negative input: Al has a - 2/s gain (D1 off and D2 on), A2 has a + Vi gain and the total voltage transfer is -1 between output and input. PI allows a fine trimming of the -1 gain for the negative input signals. A3 adds a continuous voltage to the rectified positive signal in order to attack A4 which acts as a ± multiplier commanded by the TTL input through the analog switch. Sat, 15 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Accurate-ramp-generator-l13659.htmlThe ramp generator, an inexpensive alternative to commercial function generators, provides a more linear and repeatable output than conventional analog integrators. The circuit provides a triangle waveform in burst mode; in this case, two cycles of 10.24 ms each per input trigger pulse. IC4 is a dual monostable multivibrator (one shot) in which the A side is configured as a latch (see Multivibrator IC performs extra tasks, EDN, September6, 1984, p. 232). Sat, 15 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-generator-l12088.htmlThe circuit has both square-wave and triangle-wave output. The left section is similar in function to a comparator circuit that uses positive feedback for hysteresis. The inverting input is biased at one-half the Vcc voltage by resistors R4 and R5. The output is fed back to the non-inverting input of the first stage to control the frequency. The amplitude of the square wave is the output swing of the first stage, which is 8 V peak-to-peak. The second stage is basically an op amp integrator. Mon, 10 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Logic-Probe-l14328.html By connecting this circuit to a logic device that"s under power, you can get an indication as to its status. If the circuit is Sat, 08 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/4093-Cmos-Vfo-Circuit-l14882.html Two gates of a Quad 4093 are used in an astable multivibrator. CI is a three-gang 365 pF variable capacitor with sections paralleled. Tue, 04 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Precise-One-Shot-Circuit-l14957.html This approach uses a Hip-Hop, a shift register, and two gates (A). Before the one-shot pulse, the output of the NOR gate is 0. Consequently, the data input of the D-type flip-flop is equivalent to the trigger. When a trigger pulse is present, the flip-flop initiates the one-shot pulse, and the n-stage sliift register controls the pulse width, tw, which is a multiple of the clock`s period (B). The precision of the one- shot, pulse is determined by the clock period, which is inversely proportional to its frequency. For the circuit to work properly, the width of the trigger pulse, tw(, should be greater than one clock period. Mon, 03 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Wide-frequency-oscillator-l12078.htmlAn oscillator/amplifier is resistively tunable over a wide frequency range. Feedback circuits containing operational amplifiers, resistors, and capacitors synthesize the electrical effects of an inductance and capacitance in parallel between the input terminals. The synthetic inductance and capacitance, and, therefore, the resonant frequency of the input admittance, are adjusted by changing a potentiometer setting. Thu, 29 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Oscillator-IIV-l12223.html When the oscillator is connected to a dc circuit then connect a dc blocking capacitor in series with the potentiometer's wiper arm. Wed, 28 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/High-current-oscillator-l13722.htmlThe oscillator output of the XR-567 can be amplified using the output amplifier and high-current logic output available at pin 8. In this manner, the circuit can switch 100-mA load currents without sacrificing oscillator stability. Tue, 27 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Programmable-pulse-generator-l12931.htmlFast rise and fall times require the use of high speed switching transistors for the differential pair, Q4 and Q5 Sat, 24 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Phase-Locked-Loop-Circuit-l14806.html The PLL will lock onto an input signal. Both triangle- and square-wave outputs are available. Sat, 24 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Capacitor-Allows-Higher-Slew-Rates-l14508.html In this circuit, a Burr-Brown op amp supplies a slew rate of 135 V/. The addition of C2 charges the high Tue, 20 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Last-cycle-completing-gated-oscillator-l13546.htmlRegenerative feedback at C enables the oscillator to complete its timing cycle, rather than immediately shutting it off. Sun, 18 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Quad-op-amp-generates-4-waveforms-l12076.htmlA quad op amp can simultaneously generate four synchronized waveforms. The two comparators (Al and A3) produce square and pulse waves, while the tWo integrators (A2 and A4) give triangular and sawtooth waves. Thu, 15 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-Generator-l14106.html Using an Intersil ICL8038, this function generator generates frequencies from 1 Hz to over 80 kHz. Rl is the fine freque Sun, 11 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-frequency-TTL-oscillator-l12367.htmlThis oscillator uses standard inverters, one resistor and one capacitor, and has no minimum operating frequency. R and C must be chosen such that currents into the gates are below recommended operating limits and that leakage current into the gates and into C are small in comparison with the current in R also the output should be buffered (13) to prevent variations in load affecting frequency. Sat, 10 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/5Mhz-vfo-l12324.htmlA JFET (Ql) serves as the oscillator. D2 helps to stabilize the transistor by limiting positive sinewave peaks and stabilizing the bias. Output from Ql is supplied to a class A buffer, Q2. It operates as a broadband amplifier by means of Tl, which is untuned. Output amplifier Q3 is also a class A stage. A low-pass, single-section filter is used at the output of Q3 to remove some of the harmonic currents generated within the system. Fri, 09 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Precision-Gated-Oscillator-Circuit-l14876.html A 1-kHz gated oscillator with no long turn-on cycle is show. R2, R3, and D1 preset the voltage Fri, 09 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Waveform-generator-l12085.htmlThe circuit is designed around the Intersil 8038CC. Frequency range is approximately 20 Hz to 20 kHz—a tuning range of 1000:1 with a single control. The output frequency depends on the value of C2 and on the setting of potentiometer Rl. Other values of C2 change the frequency range. Increase the value of C2 to lower the frequency. Wed, 07 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Miller-oscillator-l12636.htmlThe drain of the JFET Miller oscillator is tuned to the resonant frequency of the crystal Wed, 07 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Marker-generator-l13245.htmlThe oscillator section uses three sections of a 7400 quad NAND gate integrated circuit. The 1-MHz signal from the oscillator is fed into a 7 490 decade counter configured to divide by ten, providing the 100kHz signal. To obtain the 50 and 25kHz outputs, the 100-kHz signal is further divided by 7473 dual J-K flip-flop. The first half of the 74 73 divides the 100-kHz signal by two, yielding the 50 kHz signal. The second half of the 7473 again divides by two, giving the 25kHz signal. S2 selects the output, a square wave, rich in harmonics. Wed, 07 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Ramp-Generator-l14341.html Providing a 0-to 10-V excursion from 0.4 Hz to 100 kHz, this circuit offers both simplicity and small size. The negative cur Fri, 02 Nov 2012 00:11:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Precision-clock-generator-l12635.htmlThe CMOS IC directly drives 5 TTL loads from either of 2 buffered outputs Sun, 28 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Hc-based-oscillators-l13540.htmlTwo inverters, one resistor, and one capacitor are all that is required to make a HC(T)-based oscillator that gives reliable operation up to about 10 MHz. The use of two HC inverters produces a fairly symmetrical rectangular output signal. In the same circuit, HCT inverters give a duty factor of about 25%, rather than about 50%, since the toggle point of an HC and an HCT inverter is 1 /z Vee, and slightly less than 2 V, respectively. Thu, 25 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Very-low-duty-cycle-pulse-generator-l13656.htmlUsing a precision oscillator and a few CMOS counters, you can build a precise, very low dutycycle pulse generator. You can add as many counters as you desire to make the period as long as you wish. Thu, 25 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Inexpensive-Pulse-Generator-For-Logic-Troubleshooting-l14329.html Built around a 555 timer IC, this pulse generator can be built into a probe for logic Thu, 25 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Furnace-Fuel-Miser-Circuit-l14790.html A timer (LM555CN) and decode counter is used to generate duty cycles from 10% to 100% to control the time a heating system can operate. V2 is a decode counter that can be switched from 10% to 100% duty cycle. V3A and form a latch that drive Al, LED1, and V4. The triac TRI is used as an ac switch, in series with the thermostat that controls the heating system. Electric-heating systems thai do nut contain a low-current thermostat (as in the previous installation), use a heavy-duty thermostat that directly feeds current to the heating element.For such systems, it will be necessary to install a heavy-duty relay (Kl in this example) to control the heavy heating-element current. Mon, 22 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Oscillator-with-frequency-doubled-output-l12369.htmlThe current-controlled oscillator frequency can be doubled by applying a portion of the square-wave output at pin 5 back to the input at pin 3, as shown. Fri, 19 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Code-practice-oscillator-l12225.htmlThe inexpensive 7404 hex-inverter has enough amplification to handle a wide range of transducers. Closing the key completes the battery circuit and applies four to five volts to the 7404. Bias for the first two inverter amps (Ula and Ulb) comes from the two resistors, Rl and R2, connected between their inputs and outputs. The capacitor and rheostat (R3/C1) close the feedback loop from the input to the properly-phased output. The signal leaving Ulb drives the remaining four inverter amplifiers, Ulc through Ulf; they, in turn, drive the phones or speakers. Wed, 10 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-height-to-width-converter-l13225.htmlThe output-pulse width from the circuit is a linear function of the input pulse"s height. You can set the circuit"s input threshold to discriminate against low-level pulses, while fixed components limit the circuit"s maximum output -pulse width. With a 270-KO resistor connected from the -9 V supply to the base lead of Q2, this circuit can handle input pulses separated by 20 p.s for correct operation. The tum-off time of zener diode D2 sets the lower limit for the input-pulse repetition rate. Wed, 10 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Code-practice-oscillator-l12465.htmlThe circuit consists of a basic oscillator (above dashed line) and an automatic keyer (below dashed line) Mon, 08 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Four-output-waveform-generator-l13329.htmlMany applications require control signals that have phase shifts with reference to an input signal. Circuit accepts a sine, square, or triangular wave as an input reference signal and produces square-wave outputs with 0", 90", 180", and 270" phase shifts with respect to the input. Figure 38-3B shows the input and output waveforms. The circuit contains two !Cs: an LM565 phase-locked loop and a 7474 dual-D positive edge-triggered flip-flop. R1 and C1 set the free-running frequency of the LM565"s VCO. You should adjust R1 so that the frequency is approximately four times that of the input reference signal. Sat, 06 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/temperature-stable-oscillator-l12224.htmlThe Colpitis sinusoidal oscillator provides stable output amplitude and frequency from 0°F to +150°F. In addition, output amplitude is large and harmonic distortion is low. Oscillation is sustained by feedback from the collector tank circuit to the emitter. The oscillator's frequency is determined by: Potentiometer R3 is an output level control. Control Rl may be used to adjust base bias for maximum-amplitude output. Mon, 01 Oct 2012 00:10:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Waveform-generator-II-l12087.htmlThe circuit uses a CA3060 triple OTA (two units serve as switched current generators controlled by a third amplifier). A CA3160 BiMOS op amp serves as a voltage follower to buffer the 0.0022 µ¥ integrating capacitor. The circuit has an adjustment range of 1,000,000:1 and a timing range of 20 µ& to 20 sec. The "ON-OFF" switch actuates an LED that serves as both a pilot light and a low-battery indicator. Sat, 29 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Transistor-Pulse-Generator-l14332.html Seven-V narrow pulses from 2 Hz to 50 kHz are produced by this circuit. CI through C4 provide frequency ranges i Fri, 28 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Harmonic-Generator-l14506.html This circuit can extract harmonics from various waveforms. With a sloped input waveform, the comparator produces a pulse Tue, 25 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Versatile-two-phase-pulse-generator-l12932.htmlTwo-phase clock generator uses two L161s to generate pulses of adjustable widths and phase relationships Mon, 24 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/10Khz-oscillator-l13091.htmlThe capacitor charges until switching voltage is reached. When SUS switches on, the inductor causes current to ring Fri, 21 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Xor-gate-oscillator-l13551.htmlAn exclusive-OR gate, IClD, turns a simple CMOS oscillator into an FSK generator. When the data input increases, IClD inverts, and negative feedback through R2 lowers the circuit"s output frequency. A low input results in positive feedback and a higher output frequency. Rl and C set the oscillator"s frequency range, and R2 determines the circuit"s frequency shift. Wed, 19 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Monostable-circuit-l12867.htmlIf the output is low, application of a negative-going pulse to the trigger input sets the flip-flop (Q goes low), drives the output high, and turns off 1. Capacitor C is then charged through Ra until the voltage across the capacitor reaches the threshold voltage of the threshold input. If the trigger input has returned to a high level, the output of the threshold comparator will reset the flip-flop (Q goes high), drive the output low, and discharge C through Ql Fri, 14 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Two-function-signal-generator-l13345.htmlYou can continuously vary the frequencies of the triangle and square waves produced by this circuit over a full decade. Thu, 13 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Sawtooth-Converter-l14029.html Simple function generators normally provide sinusoidal, rectangular, and triangular waveforms, but seldom a sawtooth. Th Thu, 13 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Local-Oscillator-For-Double-Balanced-Mixers-Circuit-l14873.html This circuit has an amplifier to supply +10 dBm to an SBL series (Mini-circuits) or similar type doubly-balanced mixer assembly. This circuit has values shown for =80- to 90-MHz crystals, Mon, 10 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Staircase-generator-l12376.html Two CA3130's are used, one as a multivibrator and the other as a hysteresis switch. The third amplifier, a CA3160, is used as a linear staircase generator. Sun, 09 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-Frequency-Multiplier-l14225.html This circuit uses a comparator as a Schmitt trigger (311H) and two active bandpass filters (LM318H). 3-kHz output Sun, 09 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Digital-Sawtooth-Generator-l14339.html This straightforward circuit uses an NE555 timer as an oscillator, a 7493 counter chain and a DAC0806 D/A conver Sat, 08 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Clock-Driven-Triangle-Wave-Generator-Circuit-l14687.html U2-a, 03 and R2 operate as an integrator. Q2 and Q3 are alternately switched at 256 cycles. Tue, 04 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Positive-Pulse-Pulse-Stretcher-l14334.html A simple pulse stretcher built with two sections of an op amp uses voltage follower U1A to drive Dl and C2. Mon, 03 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Wide-ranging-pulser-l13657.htmlAn output pulse"s characteristics depend upon two multivibrator"s timing components. IC1"s freerunning astable-mode frequency sets the pulse"s prf, Sat, 01 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Full-Wave-Rectifier-To-10-Mhz-l14507.html Using two CA3450 op amps and a CA3227 transistor array, this circuit will accurately full-wave rectify sign Sat, 01 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Code-practice-oscillator-II-l12476.htmlOscillator, works with2 to 12Tdc (but 9 to 12 volts gives best volume and clean keying) Sun, 26 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Glitch-Free-Clipper-l14504.html Adding a simple clamping circuit to a Harris 2620 high-speed op amp produces a glitch-free amplifier/ clipper. The op a Thu, 23 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Cmos-short-pulse-generator-l13658.htmlComprising two low-power, CMOS chips, thepulse generator produces a precise pulse width in the 50 to 500 ns range. ICl is a dual monostable multivibrator (one shot) in which each positive trigger pulse initiates simultaneous positive output pulses at pins 6 and 10. In response, XOR gate IC2 produces a positive pulse whose duration is equal to the difference between the two input-pulse durations. Section 1 of the one shot generates an approximate 1-~ts reference pulse-shorter pulses are more susceptible to manufacturing variations caused by parasitic layout capacitance. Wed, 22 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/High-frequency-oscillator-l13545.htmlIntended primarily as a building block for a QRI"transmitter, this 20-MHz oscillator delivered a clean 6-V, Tue, 21 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Simple-Staircase-Generator-l14340.html U2 is a decade counter /divider, Ul is used as a switch debouncer. For a self-generating system, connect a resis Sat, 18 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Variable-Duty-Cycle-Oscillator-Circuit-l14878.html Using a potentiometer and steering diodes, this 1.2-kHz oscillator will provide 1 to 99% duty cycle. Vary CI to change frequency. Fri, 17 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Code-practice-oscillator-l13553.htmlCapacitor C 1 charges through resistor Rl, and when the gate level established by potentiometer R2 is high enough, the SCR is triggered. Current flows through the SCR and earphones, discharging Cl. The anode voltage and current drop to a low level, so the SCR stops conducting and the cycle is repeated. Wed, 15 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Simple-Wlen-Bridge-Oscillator-l14271.html In this circuit, the Wen-bridge network provides phase shift, and the lamp regulates the amplitude of the osc Mon, 13 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Integrator-ramp-generator-with-initial-condition-reset-l13660.htmlChannell is wired as a conventional integrator, and channel2 as a voltage follower. When channel2 is switched on, the output will follow VJN and C will discharge to maintain 0 V across it. When channel! is then switched on, the output will initially be at the instantaneous value of VJN, and then will commence integrating towards the opposite polarity. Fri, 10 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Rectangular-Triangular-Waveform-Converter-l14031.html Many function generators are based on a rectangular waveform generator that consists of a Schmitt Wed, 08 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Signal-Conditioner-l14505.html This circuit takes audio from a receiver that might have a weak CW or tone signal and uses a PLL (Ul) to recover the wea Wed, 01 Aug 2012 00:08:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Variable-duty-cycle-oscillator-l13538.htmlIn a basic astable timer, configuration timing periods 11 and 12 are not controlled independently. The lack of control makes it difficult to maintain a constant period, T, if either 11 or 12 is varied. In this circuit, charge RAB and discharge R8 c resistances are detenriined by the position of common wiper arm~ of the potentiometer. So, it is possible to adjust the duty-cycle by adjusting 11 and 12 proportionately, without changing period T. Tue, 31 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Four-decade-variable-oscillator-l12220.htmlThe circuit consists of a variable current source that charges a capacitor, which is rapidly discharged by a Schmitt-trigger comparator. The sawtooth waveform thus produced is fed to another comparator, one with a variable switching level. The output from the second comparator is a pulse train with an independently adjustable frequency and duty cycle. The variable-frequency ramp generator consists of capacitor Cl, which is charged by a variable and nonlinear current source. Fri, 27 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Audio-Function-Generator-l14105.html Using an EXAR XR2206, this generator will produce sine, square, and triangular waves from 10 Hz to 100 kHz. Ul is Fri, 27 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Ua2240-staircase-generator-l13724.htmlThe uA2240 timer/counter, combined with aprecision resistor ladder network and an op amp, form the staircase generator. In the astable mode, once a trigger pulse is applied, the uA2240 operates continuously until it receives a reset pulse. The trigger input at pin 11 is tied to the time base output at pin 14, resulting in automatic starting and continuous operation. The frequency of the time-base oscillator, TBO, is set by the time constants R1 and C1 (f = 1/RIC1). For this example, a 10-KO resistor and a 0.01-I"F capacitor form the timing network. Sun, 22 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Digital-frequency-doubler-l13322.htmlThe circuit doubles tbe frequency of a digital signal by operating on botb signal edges. Each transition causes exclusive-OR gate IC1 to produce a pulse, which clocks flip-flop IC3 after propagating through buffers IC2C and IC2B. Ifyou remove capacitor Cl, tbe circuit produces narrow output pulses. Thu, 12 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Odd-number-counter-divider-l13324.htmlThis circuit, shown symmetrically, divides an input by virtually any odd number. The circuit counts n + 1/2 clocks twice to achieve the desired divisor. By selecting the proper n, which is tbe decoded output of the LS161 counter, you can obtain divisors from 3 to 31. The circuit, as shown, divides by 25; you can obtain higher divisors by cascading additional LS161 counters. The counter and IC5A form the n + 1 /z counter. Once the counter reaches the decoded count, n, IC5A ticks off an additional 1/z clock, which clears the counter and puts it in hold. Mon, 09 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Deluxe-Radar-Detector-l14338.html This simple radar detector includes an audio amplifier for driving a loud speaker. As in Fig. 69-1, it uses an op amp Sun, 08 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Ramp-generator-l12086.htmlThe linear charging ramp is most useful where linear control of voltage is required. Some possible applications are a long period voltage controlled timer, a voltage to pulse width converter, or a linear pulse width modulator. Ql is the current source transistor, supplying constant current to the timing capacitor Ct. When the timer is triggered, the clamp on Ct is removed and Ct charges linearly toward Vcc by virtue of the constant current supplied by Ql. The threshold at pin 6 is Â¥3 Vcc; here, it is termed Vc. Thu, 05 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Quadrature-outputs-oscillator-l13723.htmlThe XR-567 functions as a precision oscillator with two separate square-wave outputs at pins 5 and 8, that are at nearly quadrature phase with each other. Tue, 03 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Single-op-amp-oscillator-l12930.htmlThis circuit has a Schmitt trigger and integrator built around one op amp. Timing is controlled by the RC network. Voltage at the inverting input follows the RC charging exponential within the upper and lower hysteresis levels. By closing the switch SWI, the discharge time of the capacitor becomes ten times as fast as the rise time Mon, 02 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Basic-function-generator-l13355.htmlThis function generator uses a CA3260 BiMOS op amp to petform both the integrator and switching functions. A 620-pF capacitor and 2-KO resistor shape feedback square wave to reduce spikes. Full audio spectrum, 10Hz to 20kHz, is covered with a single 100 potentiometer. Sun, 01 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Sine-Wave-Square-Wave-Converter-l14035.html An op amp used as a comparator produces a 10-V p-p square-wave output with 100-mV input, to 15 kHz. Adjust Fri, 29 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Strobe-tone-burst-generator-l13089.htmlWith a dual supply voltage, the external capacitor on pin 10 can be shorted to ground to halt the 8038 oscillation Tue, 26 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Light-Controlled-Oscillator-Circuit-l14747.html This circuit can be used as a light detector and possibly as an aid for the visually handicapped. Sun, 24 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Fixed-frequency-generator-l13341.htmlA single op amp, one fourth of an LM324 quad op amp, is configured as a standard inverting amplifier. At power up, a positive voltage is applied to the noninverting input of Ul, via R3, forcing its output high. That high output travels along three paths.. The first path is the tone output. Along the second path, by way of R5, that high is used as the drive Ul is fed back, via R4, to the inverting input of Ul. That forces Ul "s output to go low. Sat, 23 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Automatic-ttl-morse-code-keyer-l12482.htmlAutomatically generated dits and dahs are produced over a speed range of 11 to 39 wpm. The upper limit can be raised by decreasing R2 Fri, 22 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Butler-emitter-follower-oscillator-l12631.htmlThis circuit operates at or near series resonance. It is a good circuit design with no parasitics Wed, 20 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Delayed-pulse-generator-l12292.htmlThe circuit offers independent control of initial delay and pulse rate. ICIc is connected as a pulse generator whose operation is inhibited by the normally low O/P of the ICla. When the circuit input goes low i.e., by pressing PB1, IClb O/P goes high and the circuit O/P goes low thus replicating the input. When the input is kept low capacitor Cl charges via R2 to a point where ICla O/P goes low. This allows the pulse generator ICIc to start and "rapid fire" pulses appear at the circuit O/P. When the circuit input returns to the high state Cl is rapidly discharged viaD1 and Rl. Tue, 19 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-Generator-Circuit-l14955.html By using a 556 dual timer with IC1A acting as a waveshaper and 1C1B as a pulse generator, a 10:1 range of pulse widths can be generated. Tue, 19 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Phase-Shifter-l14503.html This circuit adds 120 degrees of phase shift to a 50- or 60-Hz input, regardless of the frequency and amplitude fluctuations Mon, 18 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Triangle-generator-l13346.htmlThis circuit generates a symmetrical, 10-m V pk-pk triangle waveform which is summed with a de level and connected to the aid analog input for noise/DNL testing. The de level input offsets the triangle waveform over the input range of the ADC. Sat, 16 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pattern-Generator-For-Radio-Direction-Finding-Circuit-l14750.html In order to display polar quantities (magnitude and direction of a received radio signal), a sine and cosine voltage proportional to an angle (antenna direction) is needed. In this case, a sine-cosine potentiometer coupled to a directional antenna and a sample of a voltage proportional to received signal is used to display Sat, 16 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-generator-l12929.htmlThe duty cycle Of the output pulse is equal to R4/(R4 + R5) x 100%. For duty cycles of less than 50%, Dl can be eliminated and R2 raised Fri, 15 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Triangle-square-wave-generator-l13332.htmlThe programmable multiple output generator provides the control signals for data converter ATE. Major performance criteria are simple, interfaces to a number of microprocessor systems, low power consumption, stable output timing relationships combined with a minimum of board space. For schematic simplicity only, one output circuit is shown in full. The monolithic HS7584 provides four current output DAC"s with four quadrant multiplication, individual reference input and a feedback resistor. Sun, 10 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Second-Order-Polynomial-Generator-Circuit-l14749.html By using a circuit built with a single analog multiplier and five precision resistors, an output voltage (Ko) can be made to create a second- order polynomial. The circuit implements the quadratic shown. The input terminals of IC1 are connected to create a positive square term and present the Vr signal to the output with a 1-10-V scale factor. Incorporating the voltage-divider network (resistors R3 and R4) in the input signal path provides additional attenuation adjustment for the coefficient (c) of the square term in the quadratic. Fri, 08 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Fast-Low-Duty-Cycle-Pulse-Oscillator-l14335.html This simple and symmetrical free-running generator has a 50- output impedance, a pulse width of 100 ns Thu, 07 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Fifth-overtone-oscillator-l12614.htmlThis circuit isolates the crystal from the dc base supply with an rf choke Sat, 02 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Stable-Vfo-l14272.html This VFO circuit covers from 2.13 to 2.58 MHz and is intended for use with an external mixer to heterodyne the signal to desired Sat, 02 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Line-synchronized-driver-l13280.htmlThe gate drive that phase controls the four parallel SCRs is accomplished with complementary MOS hex gate MC14572 and two bipolar transistors. This adjustable line-synchronized driver pennits SCR conduction from near zero to 180 degrees. A Schmitt trigger clocks a delay monostable multivibrator that is followed by a pulse-width monostable multivibrator. Line synchronization is achieved through the half-wave section of the secondary winding of the full-wave, center-tapped transformer. Fri, 01 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Triangle-Wave-Generator-Circuit-l14686.html This is a simple triangle-wave generator using two IC devices and a transistor. The triangle wave is used as feedback to the square-wave generator. SI allows range switching in three ranges from 100 Hz to 100 kHz. Fri, 01 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/1-khz-oscillator-l12219.htmlThis circuit operates as an oscillator and a timer. The 2N6028 is normally on due to excess holding current through the 100 k resistor. When the switch is momentarily closed, the 10 µ¥ capacitor is charged to a full 15 volts and 2N2926 starts oscillating (1.8 and 820 pF). Wed, 30 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-Power-Ring-Counter-Less-Than-6-Mw-l14331.html The ring counter operates from 1.0 to 6,0 V and requires only 6 mW at 1.5 V. The reset pulse turns Wed, 30 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Very-Low-Frequency-Multivibrator-Circuit-l14836.html The use of JFETs permits, high resistance and long time constants in this very low frequency multivibrator. Tue, 29 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Butler-aperiodic-oscillator-l12640.htmlThis circuit works well in the range of 50 kHz to 500 kHz. Slight component modifications are needed for higher frequency operation Mon, 28 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Cmos-oscillator-l13552.htmlThe common clock oscillator in Fig. 68-19A has two small problems: It might not, in fact, oscillate if the transition regions of its two gates differ. If it does oscillate, it might sometimes oscillate at a slightly lower frequency than its equation predicts because of the finite gain of the first gate. If the circuit does work, oscillation occurs usually because both gates are in the package and, therefore, have logic thresholds only a few millivolts apart. Mon, 28 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Audio-oscillator-l12330.htmlA Wien bridge oscillator produces sine waves with very low distortion level. The Wien bridge oscillator produces zero phase shift at only one frequency (f = Vx t RC) which will be the oscillation frequency. Stable oscillation can occur only if the loop gain remains at unity at the oscillation frequency. The circuit achieves this control by using the positive temperature coefficient of a small lamp to regulate gain (Rf/RLAMp) as the oscillator attempts to vary its output. The oscillator shown here has four frequency bands covering about 15 Hz to 150 kHz. Wed, 23 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/300V-pulse-generator-l13655.htmlIn this TMOS pulser, a negative-going pulse is applied to Ul, a high-speed CMOS buffer, which directly drives the gate ofQl, an MTP3N35. If only a 100-V pulse is required, the MTA6Nl0 can be used. Tue, 22 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Signal-Generator-Circuit-l14769.html Useful for troubleshooting audio, video, and lower frequency RF amplifiers, Sun, 20 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Phase-tracking-three-phase-generator-l12373.htmlUsing a single chip LM324 can, with active R-C networks, reduce the size of a 3-phase waveform generator, and prove useful in compact and stable 3-phase inverters. One quarter of an LM324 is used as a Wien bridge oscillator generating a pure sinusoidal waveform while the remaining parts of the LM324 are used as three 120° fixed phase shifters. Fri, 18 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-generator-as-astable-multivibrator-l12293.html The pulse repetition rate is selected by positioning SI to the desired position and the rate remains essentially constant when the resistors which determine on-period and off-period are adjusted. Tue, 15 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Adjustable-function-generator-l13088.htmlThis low-cost operational-amplifier circuit (A) generates four different functions with adjustable periods. For the components shown here, the period of the output waveforms is given by T = 4RC and T = 2RC. With switch SI in position A, VI is a triangular waveform, while V2 is a square wave (B) Sun, 13 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-frequency-fm-generators-l13337.htmlHere are two FM generators for low frequency, less than 0.5 MHz center frequency, applications. Each uses a 566 function generator as a modulation generator and a second 566 as the carrier generator. Capacitor Cl selects the modulation frequency adjustment range and Cl selects the center frequency. Sun, 06 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/two-tone-generator-l12337.htmlTwo 741 operational amplifiers are used for the active element in this Wien bridge oscillator. (The 1458 is the dual version of the 741.) Frequencies of the two oscillators were chosen to fit standard component values. Other frequencies between 500 and 2000 Hz can be employed. They should not be harmonically related. Sat, 05 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Harmonics-generator-l13336.htmlTwo comparators and a summing amplifier that generate differential harmonic spectra comprise a simple frequency multiplier. The resulting circuit can extract harmonics from a sine, triangle, sawtooth, or any other sloping-sided waveform. With a sloped-input waveform, a comparator produces an output pulse width that"s proportional to the input amplitude plus a reference voltage. Changing the reference can vary the pulse width from 0 to lOO%. As the pulse width changes, the harmonic spectrum changes, but two comparators combined in the adder eliminate harmonics, depending on the duty cycle. Sat, 05 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Low-frequency-oscillator-l13548.htmlThis simple rc oscillator uses a medium-speed comparator with hysteresis and feedback through Rl and Cl as timing elements. The frequency of oscillation is, at least theoretically, independent from the power supply voltage. Sat, 28 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Add-On-Pulse-Generator-Circuit-l14954.html This pulse generator can supplement a standalone pulse generator. Using a transistor and a 555 timer, pulse widths of 5 to 500 can be produced. The value of C3 is approximately found from the formula: C3 uF = 1.1 x10-5 T where T is the shortest pulse width (uS) desired in a 10:1 range (T should be greater than 5uS). Sat, 28 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Non-integer-programmable-pulse-divider-l13333.htmlThe purpose of D-type flip-flop IC2 is to synchronize the input signal with the clock pulse. When the clock pulse changes from low to high and the input is high, IC2 output is high. Subsequently, IC3 resets to zero and starts counting up. Until the counter counts to ten, the counter is inhibited. Thus, the number of pulses of the output of IC3 is ten times input pulse. The designed frequency of the clock pulse must be ten times higher than the maximum frequency of the input. Mon, 23 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Hee-haw-l12350.htmlThe circuit uses two gates of a 7400 IC cross-connected to form an astable multivibrator driven by the 1-pulse per second output of the digital clock IC. The hee-haw circuit has a low frequency astable modulator added to make a self-contained European-type siren. Tone and rate can be varied as desired by changing capacitor values. Fri, 20 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Waveform-Generator-with-ICL-8038CCPD-l11745.htmlThat circuit is based on a 14-pin DIL IC capable of producing sine, square, triangular, sawtooth and pulse waveforms of high accuracy and stability. The frequency may be selected to be from 0.001Hz to 1Mhz, Frequency modulation and sweeping can be accomplished with an external voltage and the frequency can be programmed digitally by resistors or capacitors. Sweep range can be up to 40:1 or 1000:1 with a little less quality. Mon, 16 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Sawtooth-and-pulse-generator-l13356.htmlThe pin 3 output of the 566 can be used to provide different charge and discharge currents for Cl so that a sawtooth output is available at pin 4 and a pulse at pin 3. The pnp transistor should be well saturated to preserve good temperature stability. The charge and discharge times can be estimated by using the formula shown. Sun, 15 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Pulse-width-multiplier-l13320.htmlThis circuit for multiplying the width of incoming pulses by a factor greater or less than unity is simple to build and has the feature that the multiplying factor can be selected IYJ adjusting one potentiometer only. The multiplying factor is determined by setting the potentiometer in the feedback of the 741 amplifier. The input pulses e1, width T and repetition period Tis used to trigger a sawtooth generator at its rising edges to produce the waveform e2 having a peak value of E volts. Tue, 03 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Rf-Attenuator-l14221.html A balanced mixer is used as a control element in this circuit. An Analog Devices AD7524 D/A converter drives a voltage-contro Mon, 02 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Cmos-Vfo-Circuit-l14875.html The circuit shown has a frequency range of 2 Hz to 30 kHz, Mon, 02 Apr 2012 00:04:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Frequency-doubler-l7550.htmlThis frequency doubler using a single 4069 hex inverter IC, a frequency doubler can be constructed to give an output pulse train whose frequency is twice that of a squarewave input signal. The signal is applied to the input of N1. It should be a squarewave with a duty-cycle of approximately 50% at level compatible with CMOS logic (3-15V peak to peak depending on supply voltage). The input signal is buffered and inverted by N1, and inverted again by N2, so the outputs A and B of N1 and N2 are squarewave signals 180° out of phase. The output of N1, is differentiated by C1 and R1 and the output of N2 is differentiated by C2 and R2, giving two spike waveforms of C and D, 180° out of phase. The signals are buffered, inverted and shaped by N3 and N4. These are then combined in a NOR gate consisting of D1, D2, R3 and N5, and finally inverted by N6 to give the frequency twice that of the input signal. The circuit will operate over a wide frequency range. With the component values shown the width of pulses in E and F point is about 500ns, so the duty cycle of the output will be 50% when the frequency is 1MHZ, when the input frequency is 500KHZ.By A.M. Bosschaert Tue, 26 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/7-MHz-VFO-l7657.htmlA 7 MHz oscillator with a variable crystal oscillator (VXO) operates very stably, but it allows only a small frequency variation (approx. 5 kHz). In contrast, a VFO with an LC resonant circuit can be tuned over a range of several hundred kHz, but its frequency stability will depend upon its construction. The use of a ceramic resonator as frequency-determining component fulfills both requirements. The following oscillator circuit, which uses a ceramic resonator, offers a tuning range of 35 kHz with good frequency stability. The somewhat unusual resonant LC circuit at the collector of VT1 has two functions. It improves the shape of the output signal and at the same time compensates the amplitude drop starting at approximately 7020 kHz. Sun, 24 Mar 2013 00:03:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Tunnel-Diode-Oscillator-l7464.htmlThe excess small forward current flow in a tunnel or Esaki diode is a manifestation of quantum mechanical tunneling. Tue, 05 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/30m-Band-Receiver-l7659.htmlThe direct conversion receiver described consists of only a bandpass filter, mixer IC, VFO and audio filter. With only 22 parts, this simple circuit should take a few hours at the weekend to construct. For extra simplicity, eliminate L1 & C1 and connect C2 to the slider of P1. The oscillator section of the NE612 is configured as either a series-tuned Colpitts- or Clapp oscillator. Depending on the parts the receive range is from 10050 kHz to 10250 kHz. Due to component tolerances the number of turns and/or the capacity of L3 and C7 are adjusted to tune the required portion of the band. Tue, 05 Feb 2013 00:02:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Frequency-doubler-II-l7551.html This frequency doubler uses one CMOS quad, two input NAND gate package type 4011. The frequency doubler proper consists of an inverter IC1B, two differentiating networks R1/C1, R2/C2 and NAND gate IC1A, IC1C and IC1D function as input and output buffers. In Fig.2 exist the pulses in different points of circuit. Thu, 31 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Sawtooth-generator-circuit-l7890.htmlSawtooth wave generators using opamp are very common. But the disadvantage is that it requires a bipolar power supply. A sawtooth wave generator can be built using a simple 555 timer IC and a transistor as shown in the circuit diagram. The working of the circuit can be explained as follows: The part of the circuit consisting of the capacitor C, transistor,zener diode and the resistors form a constant current source to charge the capacitor. Initially assume the capacitor is fully discharged. The voltage across it is zero and hence the internal comparators inside the 555 connected to pin 2 causes the 555's output to go high and the internal transistor of 555 shorting the capacitor C to ground opens and the capacitor starts charging to the supply voltage. Tue, 29 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Tone-Oscillator-with-555-l8189.htmlThis is a basic 555 squarewave oscillator used to produce a 1 Khz tone from an 8 ohm speaker. In the circuit on the left, the speaker is isolated from the oscillator by the NPN medium power transistor which also provides more current than can be obtained directly from the 555 (limit = 200 mA). A small capacitor is used at the transistor base to slow the switching times which reduces the inductive voltage produced by the speaker. Frequency is about 1.44/(R1 + 2*R2)C where R1 (1K) is much smaller than R2 (6.2K) to produce a near squarewave. Sat, 26 Jan 2013 00:01:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/8-stages-LFO-analogue-sequencer-l7629.htmlThe CD4060 is a CMOS 14-stage binary counter with an internal oscillator on chip. The oscillator is controlled by the resistors and capacitor tied to the timing pins, 9-11. This oscillator runs the binary counter, and the various outputs count at the oscillator speed. In particular, pins 1, 2, and 3 count at 1/16384 th of the oscillator frequency. If we set the main oscillator to run from 16384 Hz to 163840Hz, then outputs 1,2 and 3 count at from 1 Hz to 10 Hz. Tue, 25 Dec 2012 00:12:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Zener-Oscillator-circuits-l7812.htmlThese two circuits are interesting from an academic point of view. Their practical implementation is rather critical and it is not easy to get steady operation. Circuit (a) requires a "cooked" zener: connect it first to a constant current generator, then increase the current until the voltage across the zener starts to decrease. Reduce the supply current and wait a few minutes until it really warms up. The zener is now ready for the circuit: increase the voltage slowly until it oscillates (1KHz in the circuit shown). You may need to decrease the voltage once oscillation takes place. With suitable circuit components it will oscillate up to 20MHz. Thu, 06 Sep 2012 00:09:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Audio-Oscillator-schematic-l8027.htmlThe oscillator circuit (see Figure 1) involves two unity gain phase shift stages, A1 and A2, in tandem and a gain stage, A3, with back to back diodes and resistor network providing non-linear negative feedback. At a particular frequency (determined by RT and CT - the timing components) A1 and A2 provide 90 degrees phase shift each, 180 degrees in total and the circuit begins oscillating, since A3 and its non linear network has more than unity gain for small signals. As the oscillation level increases the diodes conduct and limit the gain of A3 stabilising the output at the desired level, in this case a little over 1V RMS. However, some distortion of the sine wave peaks is caused by the diodes. Mon, 30 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Direct-Digital-Synthesis-Oscillator-l7320.htmlThe AD9835 combines the Numerical Controlled Oscillator (NCO), COS Look-Up Table, Frequency and Phase Modulators, and a Digital-to-Analog Converter on a single integrated circuit. With more easy words you can say that this circuit is a oscillator where the frequency can be programmed from 0 to 25 MHz with the resolution of 0.01Hz! Here you will also be able to download controling software for your own projects. DDS stands for Direct-Digital Synthesis. This synthesizer is simply a circuit that can create a sine- wave signal from a reference crystal and a programable frequency-register. All this circuit needs is a reference oscillator (crystal) and some filter. See fig above: A crystal oscillator (50MHz in my case) is connected to the input (Clock in) of the DDS. The phase accumulator calculate the frequency you want the output to have. A sine memory map send data to the D/A and at the output you will have a sinus-signal with the desired (programmed) frequency. You can program the output frequency from 0Hz to 50MHz, but according to the sampling theory (Shannon, Nyquist) practically, the output is limited to about 45% of the maximum clock rate at which the logic can be operated. This means that the sinus-output can reach from 0 Hz to about 25MHz with a 50MHz crystal. I think that is really good. Inside the DDS is a programable divider wich divid the Clock in with 232 and multiply it with a programable register. Sun, 29 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Crystal-Clock-Generators-l7557.htmlHere exist a small collection from three generators, what using crystal for basic production of oscillations. Each generator uses different topology of circuit for the production of oscillations. Tue, 17 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Ceramic-resonator-oscillator-l7321.htmlThis receiver is MC3371. Pin 16 is the RF input to the mixer and pin1 and pin2 is the local oscillator. The product comes out at pin 3. Imagin you want to receive at 100MHz. The local oscillator is set to 100.455kHz and when the mixer mix the RF (100MHz) with the osc (100.455MHz) the product will be 455kHz and lots of other frequency products. What we want is only the 455kHz signal. And it is here the ceramic filter comes handy. It filter away almost everything except 455kHz +/- 10kHz. The signal goes to pin 5 and limits and amplifyes. A FM-demodulator brings out the sound from the 455kHz signal with the help of a quad coil. The audio signal amplifyes and comes out at pin 9. Mon, 16 Jul 2012 00:07:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Frequency-Divider-l7552.html This is a classic divider of frequency via two. It is achieved with a classic circuit T-flipFlop, round IC1 [ 4011 ]. In the circuit, the frequency of network, after are limit the negative half-s period of sine wave and transform in square wave, are divided via two. Thus for frequency50 HZ, we will take in the exit pulse of frequency 25 HZ. The supply of circuit it is + 5V and does not need high benefit in current. Sun, 24 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/38KHz-or-40KHz-signal-generator-l7822.htmlThe small 8-pin PIC12C508 is pre-programmed to generate our 38KHz carrier frequency by simply pulsing I/O-pin GP1 (shown above). The PIC will generate either 38KHz or 40KHz, depending on the state of GP3 when power is first applied. If you connect GP3 to ground, then apply power to the circuit, the frequency will be 40KHz. This was implemented for people using the older 40KHz style infrared detector modules. The default is 38KHz with pin #4 (GP3) left floating or (not connected to anything), Pin #7 (GP0) is to inhibit (stop) the carrier output. When GP0 is connected to ground, the PIC will halt generation of the carrier frequency. Sun, 24 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Triple-Waveform-Generator-with-8038-l7331.htmlThe Tri-Waveform Generator can be used for a number of different uses. The one that I use it for is a signal generator to test circuits. The frequency range is 20 to 20khz. and can be adjusted by R1. The duty cycle or the time that the waveform is high and the time that the waveform is low can be adjusted by R4. The purpose of R2 and R3 are to clean up any distortion on the sine wave output. To do this you must hook up the sine wave output to and oscilloscope and adjust R2 & R3 to make the sine wave as accurate as possible. Sun, 17 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/1-KHz-Audio-Oscillator-schematic-l8128.htmlThis circuit consists of a CMOS square wave oscillator on a frequency of approximately 1 kHz. The RC filter, which has a roll-off frequency of 500 Hz, filters the harmonics, providing a sine-wave output. Sat, 16 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Signal-Generator-20KHz-l7417.htmlThis fucntion gernerator IC is specified to work to 20 MHz. So far, this unit works nicely to 50KHz. Since I seldom need signals higher than that, it has taken up a happy home on my workbench and further development is iffy at best. There are two basic approaches to controlling the frequency in this type of device. One way is to adjust the voltage to the IC manually and then read out the frequency with a counter. The problem here is you need to fiddle around with the control knob and while waiting for the one-per-second updates on the display. Fri, 15 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Frequency-Generator-circuit-l7546.htmlThis is a useful instrument for works hops. The standard of the produced frequencies is 10 to 1. The basic frequency is produced by a crystal with high accuracy. The circuit is consisted by the oscillator, around the crystal and the frequency divider, which divides to 10. The produced pulses are quadrangular. Thu, 14 Jun 2012 00:06:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Vertical-Deflection-Amplifier-for-Oscilloscope-l7441.htmlThe vertical deflection amplifier uses a 180 degree phase splitter to generate a differential signal. The CRT requires large drive voltages, but almost no current. The oscilloscope bandwidth is limited by the amplifier chain as almost all electrostatic CRTs have a bandwidth extending to several hundred megahertz. Thu, 31 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Simple-SCR-oscillator-l7811.htmlSilicon controlled rectifiers (SCR) can easily oscillate if there is an inductor (a speaker coil in this case) which gives just enough extra voltage to completely switch off the sustain current. In this way a new cycle may start and oscillations set in. It operates over a wide range of supply voltage and components values are not critical at all. Operational frequency in this circuit goes from 100Hz at 11V to 10KHz at 100V. Tue, 29 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Oscillators-for-Buzzers-and-telephone-Earpieces-l7801.htmlIn order to generate a single note you may try these simple circuits. With only three components you may implement some basic buzzers. You need a telephone earpiece for the first circuit. Any old telephone set has got one of those magnetic earpiece that is right for our purposes. Add an extra capacitor and a transistor and you have your buzzer. Frequency of operation is about 1800 Hz and the capacitor must be changed if you wish to have a different frequency. The second circuit is implemented with a ceramic sounder: its intrinsic capacity is used to make another simple buzzer. Working frequency is 800 Hz and power drain is really low. Sat, 19 May 2012 00:05:00 MSThttp://www.next.gr/oscillators/Varius-Circuits/Function-Oscillator-using-8083-l7617.htmlBuilt around a single 8038 waveform generator IC, this circuit produces sine, square or triangle waves from 20Hz to 200kHz in four switched ranges. There are both high and low level outputs which may be adjusted with the level control. This project makes a useful addition to any hobbyists workbench as well. The waveform generation is produced by IC1. This versatile IC even has a sweep input, but is not used in this circuit. The IC contains an internal squarewave oscillator, the frequency of which is controlled by timing capacitors C1 - C4 and the 10k potentiometer. The tolerance of the capacitors should be 10% or better for stability. Mon, 23 Apr 2012 00:04:00 MST