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8051 / 8052
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H Bridge Circuit
Interconnection & Timing
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4 Band Resistor
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Meter Counter Circuits
10H2 to 2MH2 frequency counter circuit
The 7208 seven-stage decimal counter can be used as the frequency counter, it has the latch and multiplexing functions, and it has the direct digital driving circuit and the display driving circuit. 7207IC 6.5536MHZ crystal oscillator`s output frequency is divided by 2K to create the 1600HZ square wave for the multiple conversions of the...
This circuit shows an ICM7217 and an ICM7555 that are connected as a basic frequency counter. The connections between the ICM7217 and a common-cathode LED display are shown in Fig. 12-18. The frequency counter is calibrated (against a known standard) using RA as a coarse control and RB as a fine control.Notice that the ICM7555 timer is connected...
Digital 7 Segment Pulse Counter
A pulse counter can be built by using 7490 decode counter and 7557A. This circuit can count from zero to 9. Pins 3 and 2 of all 7490`s must be connected..
Frequency Counter and Timer
In counter mode it provides 1Hz resolution up to 100Mhz. In timer mode maximum resolution is 0. 0000001 Hz up to 1Hz. Resolution is reduced by one digit for each additional decade. Multiple frequency updates per second by employing a sliding window for calculation. In case the AVR should be programmable in circuit, a few modifications must be...
2Digit up/down Counter
This project comes via two circuits on 2 boards. The first circuit is designed around a PIC16F628A. It has been presented on an experimental PC board using surface-mount components and was built in less than 1 hour, with about 2 hours to write and finalise the program. See P1, P2 The project shows what can be done with a micro and you can modify
Geiger Counter Circuits
SIMPLE EVENT COUNTER
S1 is a power switch. U2 drives counter U3 by producing a pulse when S2 is depressed. U4 and DISP1 read the count of counter IC U3. S3 is a reset to zero switch. The counter is a basic one-digit circuit useful as a holding block or by itself.
Precision frequency counter
This circuit shows a simple 4-digit frequency counter using an ICM7217 and an ICM7207 (which provides the 1-s gating window and the STORE and RESET signals). The display reads hertz directly, as connected. With pin 11 of the ICM7027 connected to VDD, the gating time is 0. 1 s. This displays tens of hertz at the least significant digit. For shorter
Four stage ring counter using SUS devices
100 MHz frequency and period counter using the Intersil ICM7226B 40 pin DIP
100 MHz frequency and period counter using the Intersil ICM7226B 40-pin DIP. This circuit uses a CD4016 analog multiplexor to multiplex the digital outputs back to the function input. Since the CD4016 is a digitally controlled analog transmission gate no level shifting of the digital output is required. CD4051s or CD4052s could also be used to sel
Inexpensive frequency counter tachometer
Inexpensive frequency counter/tachometer. This circuit uses a 556 dual timer to generate the gating, not-store and not-reset signals for a ICM7217 counter. One timer is an astable multivibrator using RA, RB and C to provide an output that is positive for approximately 1 second and negative for approximately 300 to 500 s to serve as the gating si
Precision frequency counter tachometer
Precision frequency counter/tachometer. The ICM7207A provides a 1-second gating window and the store and reset signals. The display reads hertz directly. With pin 11 of the ICM7207A connected to V+ the gating time will be 0. 1 second, which gives tens of hertz in the LSB position. For shorter gating times a 6. 5536 MHz crystal may be used, giving a
SING AROUND COUNTER CONTROL
Timer start-pulse generator is fast series-transistor coincidence circuit. Slop-gate generator is one-shot mvbr that prevents 1N97A diode from passing blocking oscillator negative sync pulse until mvbr fires. Used to count number of sing-around cycles and measure total time in system for measuring ultrasonic velocity in liquids and solids. -R. L. F
The Geiger tube needs a high voltage sup-ply which consists of Q1 and its associated components. The transformer is connected in reverse; the secondary is connected as a Hartley oscillator, and RI provides base bias. Dl, D2, C4, and C5 comprise avoltage doubler. RV1 should be set so that each click heard is nice and clean because over a certain...
FREQUENCY COUNTER PREAMP
Based on the LM733 or NE592, the preamp shown has a bandwidth of 100 MHz. The FET inputs provide about 1-M © input impedance. Q4, Q5, and IC2 provide signal conditioning.
XOR GATE UP DOWN COUNTER
One can transform an ordinary binary counter, such as a 7493, into an up/down counter with mode control by adding XOR gates 7486 to the counter`s outputs. The circuit counts up when the DN/UP line is low and down when the DN/UP line is high. To use the 7493 counter to count out its maximum count length of 0 - 15, connect the QA output to the BIN i
10 MHz FREQUENCY COUNTER
The circuit consists of ICM7208 seven-decade counter U1, ICM7207A oscillator controller U2, and CA3130 biFET op amp U3. IC UI counts input signals, decodes them to 7-segment format, and outputs signals that are used to drive a 7-digit display. IC U2 provides the timing for U1, while U3 conditions the input to U1. The The circuit consists of ICM720
FREQUENCY COUNTER PREAMP
By using the preamplifier with a short length of shielded cable and clip leads, signals that generally could not generate a readout, generate precise and stable readouts on the counter. The DPDT switch is used to bypass the circuit when amplification is not needed. The preamplifier can also be used for other purposes. For example, the unit was als
MHz FREQUENCY COUNTER
This is a schematic and block diagram of a 2-MHz frequency counter. It uses and LSI counter/display driver, LCD readout, and a, few logic chips for timebase and timing pulse circuitry. Q2 and Q3 form a signal (input) amplifier. The circuit contains a crystal oscillator built around U3-c and XTALl, which provides the pri-mary timing-reference signal
OSCILLOSCOPE COUNTER PREAMPLIFIER
The circuit will provide a 20 ±0. 1 dB voltage gain from 500 kHz to 50 MHz. The low-frequency response of the amplifter can be extended by increasing the value of the 0. 05- F capacitor connected in series with the input terminal. This circuit will yield an input-noise level of approximately 10 V over a 1 5. 7-MHz bandwidth. The gain can be catib
DIVIDE BY ODD NUMBER COUNTER
This circuit symmetrically divides an input by virtually any odd number. The circuit contains n+l/2 clocks twice to achieve the desired divisor. By selecting the proper n, which is the decoded output of the 74LS161 counter, you can obtain diisors from 3 to 31. This circuit divides by 25; you can obtain higher divisors by cascading additional LS161
Built around an Intersil 7216 frequency-counter IC, this counter has a basic range of 10 MHz, a 100-MHz prescaler, and an extra frequency divider (IC3). This divider divides `oy an extra factor, as marked on S7 (see schematic), to extend the range of the counten The display is multiplexed. MAN6710 2-digit red common anode 7-segment LED displays we
FOUR MODE FREQUENCY COUNTER
This counter can measure frequencies from 2 Hz to 1 MHz, time interval, and period, and count random events. A 74C926 and 74C925 are used as the counter, and these will drive a multiplexed LED display. A 2-MHz time base is used, and a divider chain is used to derive a 1-s gate. An LM339 op amp serves as the input buffer, and CD4000 series logic is
MULTIDIGIT DEMONSTRATION COUNTER
Simple interconnection of RS7490 decade counter RS7447 decoder, and 7-segment digital display for each desired digit makes ideal counter for classroom demonstrations and Sci-ence Fair exhibits, With two additional stages added, display reaches 9999 before recycling. Use 1N914 diode in series with battery to protect against polarity reversal and
BENCHTOP FUNCTION GENERATOR WITH BUILT IN COUNTER
This circuit will produce sine, square, and triangle waves from 0. 1 Hz to 1 MHz and has a counter which will read the frequency of the function generator or an external signal of a few volts peak-to-peak that will drive the CMOS counter.
RING OF 7 COUNTER
Uses surface-barrier transistors in arrangement wherein pattern of four on stages is stepped along ring, per mining maximum number of stages in ring lo be much higher than in conventional rings. -W. Carlson, Ring Counter has Increased Count Capacity, Electronis 31:15, p 89-91.
TRANSISTORIZED THYRATRON RING COUNTER
Each bistable circuit has two opposite-symmetry germanium transistors, two diodes, and four resistors. Additional transistor Q transfers conducting stage to next position when actuated by transfer pulse. Absence of capacitors gives high-speed operation. No bias current is required from ON stage to keep other stages cut off. -J. A. Pecar, Ring Count
RING COUNTER WITH VISUAL READOUT
Uses only six components per stage. Combining of counter and indicator functions gives low battery drain. After reset button is re leased, 0. 22-mid capacitor insures that first stage turns on. Current is drown by stage only when lamp is on. Any number of stages may be included in ring. -"Transistor Manual, " Seventh Edition, General Electric...
Frequency counter BNC input schematic
This is a CMOS-compatible (and hopefully also TTL) input featuring over- and under-volatage protection. Schmitt triggers are used to allow for input with long transition times. Verified to work up to 30MHz.
Frequency counter Connection diagram
Frequency counter Counter schematic
The counter makes use of 5 cascaded CD40110 which combine a decade counter, a display latch and a 7 segment LED driver in a single chip. (The decimal points are driven by IC8x. ) The counter allows up and down counting (although only up counting is used in the frequency counter) and counts on the rising edge. An over- and underflow indicator is pro
Frequency counter Divider schematic
The divider design is pretty self-explanatory. One can choose between division by 1, 10 or 100 or no output (tied low) using the CONTROL input connected to the analog multiplexer HC4052. AC04are used to drive 3 indication LEDs as well as to buffer the signal. A single HC390 includes 2 divider by 2 and 5 which can be combined as 2 dividers by 10.
Frequency Meter Circuits
VU Meter 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...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
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