Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
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Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
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AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
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Data Bus Circuits
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Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
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voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
DIY HV Variable Cap
DIY PMA alternator
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Rectangular/Triangular Waveform Converter
Many function generators are based on a rectangular waveform generator that consists of a Schmitt
Audio Function Generator
Using an EXAR XR2206, this generator will produce sine, square, and triangular waves from 10 Hz to 100 kHz. Ul is
Using an Intersil ICL8038, this function generator generates frequencies from 1 Hz to over 80 kHz. Rl is the fine freque
This circuit uses a comparator as a Schmitt trigger (311H) and two active bandpass filters (LM318H). 3-kHz output
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
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
Transistor Pulse Generator
Seven-V narrow pulses from 2 Hz to 50 kHz are produced by this circuit. CI through C4 provide frequency ranges i
Positive Pulse Pulse Stretcher
A simple pulse stretcher built with two sections of an op amp uses voltage follower U1A to drive Dl and C2.
Fast Low Duty-Cycle Pulse Oscillator
This simple and symmetrical free-running generator has a 50- output impedance, a pulse width of 100 ns
Digital Sawtooth Generator
This straightforward circuit uses an NE555 timer as an oscillator, a 7493 counter chain and a DAC0806 D/A conver
This circuit adds 120 degrees of phase shift to a 50- or 60-Hz input, regardless of the frequency and amplitude fluctuations
Adding a simple clamping circuit to a Harris 2620 high-speed op amp produces a glitch-free amplifier/ clipper. The op a
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
This circuit can extract harmonics from various waveforms. With a sloped input waveform, the comparator produces a pulse
Full-Wave Rectifier (To 10 Mhz)
Using two CA3450 op amps and a CA3227 transistor array, this circuit will accurately full-wave rectify sign
This circuit combines the characteristics of an asynchronous S/R flip-flop and an edge-triggered JK flip-flop. It changes sta
Function Generator Circuit
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.
Triangle-Wave Generator Circuit
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.
Second-Order Polynomial Generator Circuit
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....
Furnace Fuel Miser Circuit
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...
Add-On Pulse Generator Circuit
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).
Precise One Shot Circuit
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,...
The 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
Channell 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...
Inexpensive Pulse Generator For Logic Troubleshooting
Built around a 555 timer IC, this pulse generator can be built into a probe for logic
Pattern Generator For Radio Direction Finding Circuit
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
Adjustable Vfo Temperature Compensator Circuit
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.
Pulse Generator With Variable Duty Cycle Circuit
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...
The 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...
In 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...
Delayed pulse generator
The 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...
Two 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.
Astable Oscillator Circuits
Colpitts Oscillator Circuits
Crystal Oscillator Circuits
Hartley Oscillator Circuits
RF Oscillator Circuits
Sine Wave Oscillator Circuits
Square Wave Oscillator Circuits
Volt Controlled Oscillator Circuits
Wein Bridge Oscillator Circuits
Pierce Oscillator Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity