The schematic that this is based on is my own, so it is free from Intellectual property restrictions. It is based around a 555 timer (so it could be an extension of the recent "Know Your 555 timer" article), and uses an ubiquitous LM386 audio amp so it can....

Take a good capacitor, around 100 or 1000 microfarads, and connect a small resistor, 10 or 5 ohms, in series with it. Connect to the meter and adjust that pot until the meter reads the resistance of that resistor. Repeat with other capacitors and resistors....

The electromagnetic ring launcher is comprised of four subcircuits: a clock circuit (built around U5, a 555 oscillator/timer configured for astable operation), a count-down/display circuit (built around U3), a 74190 synchronous up/down counter with BCD....

The following article discusses a few very simple intrusion detector circuits, or simply burglar alarm circuits. The presented designs are simple yet extremely effective with the functions. The triggering stage may consist of a voltage/current amplifier....

This circuit has an adjustable output timer that will re-trigger at regular intervals. The output period can be anything from a fraction of a second to half-an-hour or more - and it can be made to recur at regular intervals of anything from seconds to days....

The ubiquitous 555 timer, (hooked up for variable mark/space ratio, if you build one you`ll find out why it`s needed), and a couple of D type flip-flops, (4013), to provide the count for the ULN2003 stepper motor driver. (ULN2003`s might be hard to find off....

The following circuit shows about Nixie low voltage PSU With 555 Timer IC. Features: The coil used in this schematics is bought in the shop, ....

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The dark detector circuit shown here can be used to produce an audible alarm when the light inside a room goes OFF. The circuit is build around timer IC N....

This timer is based on a simple Monostable Circuit. The length of time the relay remains energized - the ON period - is controlled by the values of R3 & C2. And the length of time the relay remains de-energized - the OFF period - is controlled by the values....

The purpose of this circuit is to power a lamp or other appliance for a given time (30 minutes in this case), and then to turn it off. It is useful when reading at bed by night, turning off the bedside lamp automatically in case the reader falls asleep After....

This is a simple Water level alarm circuits made using 555 Timer IC. Circuit will produce an alarm when the water level reaches a preset level....

The Servo Timer II was primarily designed for parachute deployment on water rockets, but can be used for other applications. The timer controls a single RC servo motor that can open a latch on a parachute door. Once triggered the timer waits a set amount of....

A very simple electronic key code lock circuit that require few external components can be constructed using this schematic diagram. This electronic key code lock circuit is based on a common 555 timer circuit and some other common components. This low cost....

Build a circuit that will flash 5 pairs of LEDs at variable rates. To do this I designed a circuit using 5 NE555 timers. To control the variable flash rate I want to use trim pots. I am having a hard time figuring out where to lay out the trim pot and what....

This circuit is very similar to Repeating Timer No. 2. However - the addition of the light dependent resistor means that the operation of this timer can be limited to the daylight hours. R7 lets you set the level of light at which the timer will stop. The....

Here is a circuit for simulating breathing / pulsing LED with the 555 timer chip. It became very popular and i received many comments and emails with people that made this circuit and worked fine, as well as comments with people that had troubles converting....

This is Easy and Mini Timer Circuit ( Egg Timer) by IC 555. Alarm by Buzzer. This be mini timer circuit that interesting. I calls that Circuit Egg Timer. By...

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A oscilloscope would be useful in analyzing the waveforms produced by this circuit, but it is not essential. An audio detector is a very useful piece of test equipment for this experiment, especially if you don`t have an oscilloscope. The "555" integrated....

You can start to set your Square Wave Generator up using 555 timer IC through the circuit shown above. Find it match with the pinout of 555 timer IC. The osciloscope is then connected to the output of 555 timer IC in order to view the square wave. From the....

An Astable Circuit has no stable state - hence the name "astable". The output continually switches state between high and low without without any intervention from the user, called a `square` wave. This type of circuit could be used to give a mechanism....

IC1 is a 555 timer in astable mode, sending approx. 10 ms pulses to decade counter IC2. IC2 is continually reset through R3, until pin 15 is taken low through the "Fire" button. IC2 then sequences through outputs Q1 to Q7, to feed power transistors TR1 to....

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This is a 9V DC power source, to a 555 timer to get a square wave. Then fed through a Half-Wave Series Multiplier (Villard Cascade) to get a high voltage DC output. Ideally I want to be able to send a single pulse at 5V pulse from a micro-controller to the....

This egg timer, which is both simple and functional, shows once again that it is not essential to use a microcontroller for everything these days. The circuit consists of only two ICs from the standard 4000 logic family, a multi-position rotary switch and a....

Are you familiar with the basics and applications of the 555 timer IC Are you looking for a book that provides all these basics If so, CircuitsToday has started an online store from where you can buy books on 555 timer IC, which have been reviewed in detail.....

A Tv remote jammer circuit, using NE555 timer IC. By using this you can watch your favorite TV channel without any interruptions. Ie; No one can be able to change the channel by means of remote, if the circuit remains ON. The circuit is simple to make at....

For a lower parts count than the 2 transistor multivibrators, 2 LEDs can be alternately flashed with a 555 integrated circuit configured as shown in Schematic 2. I chose the combination of a 2K2 and a 47K resistor to determine the oscillation frequency along....

In the following astable multivibrator circuit, in some books, it is mentioned that the duty cycle id d=( R1+R2)/(R1+2*R2) in some other books, it is....

A schematic diagram of a touch switch circuit is shown below. This circuit consist of timer, one shoot multivibrator and touch terminal. As timer, this circuit uses 555 timer which is connected to one-shot multivibrator. The touch terminal is used to trigger....