“In this Instructable I show you how to make a simple push to push off circuit with a 555 timer.
Because I have come across several projects that use this 555 timer and I had no idea what a 555 timer does exactly, I wanted to make a project to get to know it better. Therefore a simple circuit first.
The basic 555 timer gets its name from the fact that there are three internally connected 5k resistors which it uses to generate the two comparators reference voltages. The 555 timer IC is a very cheap, popular and useful precision timing device which can act as either a simple timer to generate single pulses or long time delays, or as a relaxation oscillator producing a string of stabilised waveforms of varying duty cycles from 50 to 100%.The 555 timer chip is extremely robust and stable 8-pin device that can be operated either as a very accurate Monostable, Bistable or Astable Multivibrator to produce a variety of applications such as one-shot or delay timers, pulse generation, LED and lamp flashers, alarms and tone generation, logic clocks, frequency division, power supplies and converters etc, in fact any circuit that requires some form of time control as the list is endless.
As I said, I’m going to start simple. In this project I am going to manually control the “flip flop” circuit in the 555 timer with 2 push buttons. One push button turns on the flip flop circuit causing the output to go high and the LED to light, the other push button resets the flip flop circuit causing the output to drop and the LED to turn off.
2 Tactile switches
LED (any color)
470 Ohm resistor
9V battery clip”