555 Timer - LED Blinkie

Exploring the simplicity of the 555 timer through a simple astable mode circuit to make an LED flash.

What Is a 555 Timer?
The 555 timer is an awesome simple integrated circuit that is used in numerous applications because of how easy it is to use. I’ve wanted to build several 555 based circuits for some time, this is my exploration into the basics. We will be doing both breadboard and PCB design in this tutorial.

The 555 timer has 3 modes:

Monostable Mode - This creates a delay. In this mode an external trigger causes the timer to release a single pulse at an adjustable length of time.
Astable Mode - This creates an oscillating pulse. The output switches between high and low states at an adjustable frequency and pulse width.
Bistable Mode - This mode switches between high and low states depending on two inputs.
Our 555 timer circuit today will be utilizing the astable operating mode.”


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