Counters

Digital counter circuit

With this counter you can count laps for example (in conjunction with the Simple light trap ). The circuit uses two TTL ICs 74LSxx the series. The left IC is a decimaalteller. The input pulses 14 are counted and converted to the corresponding BCD code. This code is passed to the second IC, which is a code converter and display driver. Here the BCD code correct the display driver for LD1. ..

Digital Countdown schematic with 555

This circuit provides a visual 9 second delay using a 7 segment digital readout LED. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output held high. When the switch is opened, the timer produces an approximate 1 second clock signal, decrementing the counter until the 0 count is reached. When the zero count is reached, the 'carry out' signal at pin 7 of the counter moves low, energizing the 12 volt relay and stopping the clock with a low signal on the reset line (pin 4). The relay will remain energized until the switch is again closed, resetting the counter to 9. The 1 second clock signal from the 555 timer can be adjusted slightly longer or shorter by increasing or decreasing the resistor value at pin 3 of the timer. ..

Crystal Oscillator counter

Using a 50 Khz crystal, a count of 50000 is detected when the appropriate counter bits that add up to 50000 are all high. This corresponds to bits 15 (32768) + 14 (16384) + 9 (512) + 8 (256) + 6 (64) + 4 (16). Bits 14 and 15 are the 3rd and 4th stages of the second counter, bit 0 is the first stage of the first counter (Q1, pin 9). To use a 100 Khz crystal, each bit would be moved one to the right so the total would be (65536 + 32768 + 1024 + 512 + 128 + 32 = 100,000). Using a 1 Mhz crystal, the following bits would be needed:..

Analogue Pulse Counter Schematic

It was designed for an application in a welding machine: there are lots of bits of machinery which are cylindrical in shape and which are subjected to heavy surface wear. For instance ore crushers, and the idler and roller wheels off track laying vehicles, much used in earth moving. These wear quickly, so it makes sound economical sense to re-surface the component with a hard metal. This is typically done by a welding process, using a hard facing alloy...

7-segment display counter

A 7 segment display is manufactured encapsulating 7 LEDs inside a single case. Each LED is given a shape and position which makes it a separate "segment": lighting teo or more segment in different patterns, we can read all digits from 0 to 9 on the display. Segmenfs are conventionally identified with letters from A to G. The schematic diagram above shows the correspondence between segment position and the letter. For example, number 2 is obtained lighting segments A,B,G,E,D, whereas number 3 requires segments A, B, C, D, G. If all seven segments are lit then a number 8 is obtained. ..

Digital Up / Down Counter

This Circuit uses a CD40110BE, Up/Down Counter IC's. This IC is able to Source Each Segment with 25 mA, Giving a Very Nice Bright Display. The 7 Segment Displays MUST be a Common Cathode Type, as I have used here. All the UnMarked Resistors should be at least 680 Ohms for Up To 12 Volts Supply Voltage. For Higher Supply Voltages up to 18 volts or Reduced Currents, I would suggest Increasing these Values to 1500 Ohms. Or if you want "Reduced Power" and "Brightness", Adjust the resistor values as appropriate. Basically the Approximate Current is Supply voltage Minus 2, Divided by the Resistor Value. The Schematic posted here Only shows the First, Second, Third and Last Stages. And This board is for a counter of up to 9999. ..

1 GHz Frequency Counter

This very simple counter can be used to measure the frequency of various wireless devices. Applies in reviving the transmitter and its operation as a control monitor frequency. It can be used as a scale to the receiver. Due to the simplicity of the counter should not miss any of the equipment bastlí?e that similar facilities are still owned. Buying the parts is not a significant financial burden and required the program to the PIC is available for download. To measure the frequency of the oscillator (either the transmitter or receiver), use coaxial cable (RG58 is suitable) connected to the input port counters. At the end of the cable loop from the solder wire and place it on the oscillator coil. In some cases, the cable can be connected through a resistance of about 1 to the output amplifier stage for the oscillator...

Greenhouse irrigation controller ( PIC16F84 )

This is a simple one-valve irrigation controller made for our greenhouse. The code contains a software real-time clock (RTC) and a multiplexed 8-digit LED display and keyboard you can use in other projects. The operating software is simple, it contains a real-time clock and a day counter. The valve is turned on in regular intervals in the same time. Day setting specifies the number of days between the activations, time setting specifies the time of the day when to start. Duration is the time after which the valve will be turned off. MODE button cycles through clock, start time and duration settings. the interval and starting time set will be stored in the DATA EEPROM. Scheduling can be totally turned OFF by the ENABLE button. Irrigation can be manually turned ON/OFF any time by the START/STOP buttons ..

LED Counter with IC 4017

The circuit presented this month is a basic configuration of the very versatile 4017 IC Chip. In the most common use of the IC, it will turn on 10 separate outputs sequentially. Typically, the circuit is used to turn on a LED for certain time cycle. In the circuit shown the VR can be adjusted so that the clock output of the NAND gate will be 1 second. With this clock at 1 second intervals, the 4017 chip will turn on output # 0 to be high which will light and LED. When clock pulse 2 is received a second later, output #1 will go high which will turn on LED2. This process will continue until all 10 outputs have gone on and then it will start all over again until you turn the power off. When building this circuit you should tie the left over pins of the other NAND gates in the CD4093 to ground. Therefore, pins 5,6,8,9, 12 and 13 should be connected to ground...

Digital Stopwatch 0-60sec

By using the same circuit of the Digital Stopwatch 0-99sec , we can add an AND gate, and transform the 0 ? 99sec stopwatch to a 0 ? 60sec stopwatch. We must find a way to control the RESET function of the BCD counter, which is responsible for the counting of the seconds. As we studied above, the circuit resets when we have 99 to 100, that is 1001 1001 à 0001 0000 0000. To make a transformation successfully we must force the pulse from 59 to 60 0011 1001 à 0100 0000 on the output of the BCD counter...

Stopwatch 0-99 seconds (MC14518B)

The circuit that has been used is shown in picture 1. Through the experimental part we will explain each of the parts function, but in order to have a notion of the basic idea, let just say, that this circuit besides the 5V power supply, is fed with a pulse which comes from a crystal. The crystal?s pulse is devided properly in order to obtain the 1 Hz pulse which we need in order for the circuit to work properly, and display the seconds on the 7 segment displays, through a procedure which we will explain through the experimental part...

Digital Up-Down Counter with CD40110BE

This circuit board design uses a CD40110BE, and Up/Down Counter ICs. The CD40110BE is a dual-clocked up/down counter with a special preconditioning circuit that allows the counter to be clocked, via posting going inputs, up or down regardless of the state or timing of the other clock line...

Frequency counter 400Hz to 50MHz with PIC 16F84

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...

Binary Counter using 555 and 4042B

In this circuit diagram, an NE555 timer is used as a pulse generator producing pulses at about one-second duration. This is governed by the timing components connected to pins 2, 6, and 7. If the 100µF capacitor connected on pins 2 and 6 were reduced to 47µF, then the counting pulses will be about 1/2 second each. The output of the pulse generator at pin 3 is connected to pin 1 of the binary counter 4042B. The actual device is a 4042 but are usually advertised as CD4042BE, CD 4042BM, CD 4042BC and so on, but as far as we are concerned in this application they are all the same and will give the same results.....

This article describes a 2-Digit Counter using a Microchip PIC12F629. It shows what can be done with an 8-pin chip having just 5 output lines and one input line. The chip drives two7-segment displays and this would normally require 7 lines to drive the segments plus another one or two lines to select the displays. We have shown how a single line can be used to drive two different segments by using the tri-state of an output...