A Simple 555 PWM Circuit with Motor Example

In this tutorial, you’ll learn how to build a 555 PWM Circuit. You’ll modify the standard astable circuit with a couple of diodes. And you’ll see how you can use this to control the speed of a motor.

555 Police Siren Circuit with Build Instructions

In this tutorial, you’ll learn how to build a 555 police siren circuit using two 555 timer ICs.

The 555 timer is a popular integrated circuit (IC) for hobbyists and can be used for a great variety of projects. For this project, we are going to use it to create sound with a twist!

Instead of a “straight” sound, we are going to make the frequency change automatically so it ends up sounding like a wailing police siren.

How Does a 555 Timer Work?

The 555 timer works by using three 5 kΩ resistors to divide the supply voltage in three. Two comparators compare these voltages to the input voltage, then sets or resets a flip-flop accordingly.

Below is a diagram showing what the 555 timer looks like on the inside:

How does a 555 timer work on the inside

555 Timer Tutorial and Circuits

In this 555 Timer tutorial, you’ll learn how to use the 555 timer to do fun things.

One of the first things many do with it is to create a blinking light. But that’s just one simple example of the many things you can do with this chip. You can also control motors, create an alarm, create a musical instrument, and much more.