Counter Circuits
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The circuit described here counts the number of times that an infrared beam is interrupted. It could be used to count the number of people entering a room, for instance, or how often a ball or another object passes through an opening (handy for playing.... -
With the recent events at the Fukushima Dai-ichi nuclear power plant, I thought it would be pretty cool to build a Geiger Counter and hook it up to my NerdKit for interfacing with my computer. I`ve found this article which explains the building process.... -
This project introduces a fundamental electronics building block: the counter. Building yourself a simple circuit which increments display count every second, you are going to learn how displays work and how to drive them in the right way. For those who.... -
Because the recent events in Fukushima, Japan, brought a lot of concern on radiation levels, by popular demand, here is a simple Geiger Muller counter using the Russian tube SI-22G and a single transistor regulated inverter that puts out 400V, as required..... -
Using an Atmega8-8PU (configured for 8MHz with external crystal), a Nokia 5110 lcd, and a transistor to handle the pulses from a reed relay. A 3. 3V regulator provides the voltage for the entire circuit. Everything has been mounted on a test board, including.... -
This circuit uses an LM2917 frequency to voltage converter. The input was connected to the low voltage side of the ignition coil, and the various components around it design to produce a full scale output at 6000rpm, which corresponds to 12000 ignition.... -
The schematic for this project isn`t too, too bad to look at even though it`s not the best drawing/layout for a schematic that I`ve ever done. The basic flow is from left to right. Left side is the state machine, then the 555 timers, then counter circuitry.... -
The circuit for the Digital Tachometer/RPM Counter tutorial consists of only a few devices. Wire them up according to the following circuit diagram. The PIC I`m using is on a demonstration board, which means the clock, power and ground pins are already wired....
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A fairly simple "divide-by-1000" circuit which was first designed by Zeljko Bozic, S52ZB, in a 2006 issue of VHF Communications Magazine. The idea of this project is to extend the range of older (and cheaper) frequency counters. You can often find 100 MHz.... -
This PIC software combines frequency counter and frequency lock functions. By adding couple of transistors and operation amplifier TL082, it is possible to lock the LC oscillator frequency. Frequency reference is formed from the measured frequency itself.... -
There are other display methods than the original 8 led frequency counter has. They are perhaps easier to read and may have a format that fits better to the front of your QRP equipment. Here some examples of binary decimal displays are given. Mostly the the.... -
Apply power to the frequency counter and set the coarse (top pot) and fine (bottom pot) adjustments to show zero frequency on the display. Turn the pots counter-clockwise to set to zero. Sometimes the counter will show all squares and no digits. Disconnect.... -
The real usefulness of the SR latch comes during input switch transitions. Let`s assume the input switch is a break-before-make and the switch starts in the up position. From the prior analysis, the inputs values when the switch is up are low, low, high,.... -
555 timer is used as clock to drive RS7490 decimal timer, BCD output to 7 section LED. To adjust R1 can change the clock frequency.... -
It consists only from Microchip PIC 16F84 cpu and LCD text module. Author states that this counter is capable metering frequencies from 400Hz to 50MHz. I used faster, 20MHz version of 16F84A-20I/P, and it managed to count 80MHz oscillator output... -
The winding machine electronic counter described in the example uses LED digital display to show the wound coil turns, the use of maximum count rate is 9900 turns. The working principle The winding machine circuit is composed of the power circuit, infrared.... -
Portable counter is designed with low-power logic to minimize battery drain, yet provides good performance.Since most of milliwatt power drain is taken by digital readout, circuit blanks out LED display when there is no input signal. Time base divides 1-MHz.... -
Working principle: Two pairs of photoelectric detection devices are installed in the access channel. On one side the light source A (transmitter) and the photoresistor LDR1 (receiver) are installed in the entrance of the channel; on the other side, the light.... -
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.... -
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.... -
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.... -
Here is another little circuit I designed for radiation logging purposes. It is based on an Atmel 168 Microcontroller and a small and precise RTC device called RV3029. I also used an AT45DB41 Dataflash for this Circuit, as I had the sourcecode for.... -
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....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
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.... -
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.... -
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.... -
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.... -
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,.... -
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.... -
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.... -
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.....
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