This circuit is a missing pulse detector. It is used in the_ General Purpose Controller Board with Basic Stamp 1. This circuit is used to monitor an input pulse train, and when a pulse is missed the 555 timer output will switch low. For the General Purpose....

When the potentiometer is at the up position, the capacitor will charge quickly through both 1k resistors and the diode, producing a short positive interval and long negative interval which dims the lamp to near darkness. When the potentiometer is at the....

This circuit is based on the 7240 CMOS programmable timer chip (IC3), which has an accuracy of 0. 5 percent. It contains a time-base generator, the frequency of which is decided by a resistor and a capacitor. The basic time period is RC seconds; so, given....

For a hobby project I have bread boarded, I am considering using a pair detectors that operate as a single use physical barrier. When hit by a projectile, a trace is broken allowing +5VDC to to trigger a flipflop that is part of my gate logic for a....

I am a mechanical engineering student, and for a part of my design project I wish to use a timer as so the motor switches off about 40-50 seconds after activation. The 555 timer chip is a rectangle with a indented o on the top, i assumed this was equivalent....

The artwork style of the opamp and of the meter face both suggest that is is an ACC design and is from an old issue of ACC Notes. I have credited it as such. I scanned the second image and wrote the text below from scratch. If anybody can locate the original....

This hack replaces the thermistor (temperature sensor) of a hot tub with an adjustable value that will fool the hot tub controller into thinking that the water is a certain temperature. In addition, this circuit is turned on and off by a 24VAC line....

The following circuit shows about Flashing LED EGG Timer Circuit Diagram. This circuit using the 2N2646  transistors. Features: MPF112 FET ....

This PIC16F84a based repeater (DTMF) controller is very simple & economical to build. It also gives you hand-on experience of using & programming PIC Micro controllers. Controller measures 10cm X 6 CM and may be housed in your repeater project enclosure....

For the MAX712 charger is needed a power supply with a output voltage with at least 1. 5V higher than the maximum battery voltage. Charge completion is determinate by a voltage-slope detecting analog-to-digital converter, timer, and temperature window....

This circuit uses a 555 timer to generate a sawtooth voltage waveform across a capacitor, then compares that signal against a steady voltage provided by a potentiometer, using an op-amp as a comparator. The comparison of these two voltage signals produces a....

Make a 555 timer base circuit such that O/P pin of 555 is held LOW by default at power on, and the I/P pin is held initially at HIGH at power on. The main requirement of my circuit is that until I/P pin is held LOW for say 200ms, then only the O/P pin must....

The 555 on the right is wired as an alarm sound generator and the second 555 timer on the left is a 1 Hz astable multivibrator. The output of the left timer is to modulate the frequency of the right timer. This process will cause the right timers frequency....

This 9-minute timer switch can be used to control the light in a toilet or bathroom. The timer is started by pushing S1 and stopped by pushing S1 again. If you forget to turn it off, the controlled light will go off after nine minutes. If you need the light....

This circuit is intended for alerting purposes after a certain time is elapsed. It is suitable for table games requiring a fixed time to answer a question, or to move a piece etc. In this view it is a modern substitute for the old sandglass. Useful also for....

This circuit detects when a window is open (it can also be used with a door), indicates that the window is open by means of a red LED or a blinking LED, and emits a loud acoustic signal from an intermittent electronic buzzer to remind you to close the....

This is Simple and cheap approach to Line Following Robot, This do not have anymicro controller but just a simple basic Circuit on three 555 timers. It has a good efficiency on following all kind of curves. This Robot is no more than 1000PKR. To make a....

The IC1 is a 555 timer IC is connected for, Astable operation the clock pulses are fed to the IC2 via the 10K resistor. The IC2 is a 10 stage counter, output 6 (pin 5) is connected to RESET (pin 15), thus giving us a 6 stage counter, outputs 0 to 5. The 6 of....

This circuit is a temperature controlled version of Repeating Timer No.3 . The light dependent resistor has been replaced by a temperature dependent resistor or thermistor. And a small preset potentiometer lets you choose the temperature above which the....

As shown in the figure is a preset outage timer of electric cooker circuit. Time of the timing circuit ranges from 1 hour to 12 hours, which can be regulated by PR.The timing mode is counting typeand control method mode is preset outage timing. The circuit....

Small and interesting circuit that flashes your head lights. Automotive, head lights, circuit diagram. Built around famous NE555 timer circuit....

The circuit is built using ICM7217 integrated circuit, manufactured by Intersil, which contains a CMOS counter up / down, with 4 digits and display properly. IC3 is the clock generator circuit which provides a square wave with period 1 s clock signal is....

This is a programmable clock timer circuit that uses individual LEDs to indicate hours and minutes. 12 LEDs can be arranged in a circle to represent the 12 hours of a clock face and an additional 12 LEDs can be arranged in an outer circle to indicate 5....

The following circuit shows about Frequency Voltage Converter Circuit. This circuit based on the LM331 IC, Features:15V DC as the accumulation ....

..

Pulses are received by the timer from the distributor points. When the timer output is high, Meter M receives a calibrated current through R6. The meter don`t....

Here is a really simple game show timer designed with the beginner in mind! The power source is an ordinary 12 volt lantern battery or battery pack made up of C or D cells. The lamps may be ordinary flashlight bulbs; the prototype uses 750 mA Krypton types....

This is basically a flasher circuit modified to turn on and off a bulb instead of a LED. It uses a 555 timer IC working as an astable multivibrator. The flashing rate can be varied from very fast to a maximum of once in 1. 5 sec by varying the preset VR1. ..

A simple timer that can be used to turn on/off a load after user specified time. The prototype was developed using xBoard MINI, a low cost easy to use ATmega8 development board. The program was burned to the MCU`s flash memory using eXtreme Burner - AVR....

This project describes a digital clock with alarm function. It uses a PIC16F877 microcontroller to generate an accurate 1 sec delay with Timer0 using Roman`s zero error method. The time is displayed in large size font on a 4G—20 character LCD that uses....

This easy electronic buzzer circuit built based on timer works for gaining the frequency. The IC timer NE 555 used as astable multivibrator operating at about 1kHz and produces a sound when switched on. The sound frequency can be adjusted b....

As this controller has been designed primarily for controlling model trains, it is designed to deliver around 12-15 Volts, although this system should work with as low a voltage as 3V (indeed it also works on a 6V supply to control some accessories I have).....