Pulse Width Modulation or PWM is widely used in today’s world due to its requirement for controlling many devices in every field of Electronics. PWM Signal is widely used for controlling motor, Dimming LED lighting and a lot more.

So, in this Tutorial let me show you a very quick and easy way to generate such PWM signal so without any more further ado Let’s get started!

Step 1: Watch the Video!

If you don't want to read all the stuff you can watch My video on Youtube!

Step 2: What Is PWM?

Let’s first understand What is PWM?

PWM is a digital signal. This signal is set high (5v) and low (0v) in a predefined time and speed, which will be our frequency. The time during which the signal stays high is called the “on time” and the time during which the signal stays low is called the “off-time”.

The percentage of time in which the PWM signal remains HIGH is called as duty cycle. If the signal is always High its 100% duty cycle, if half the time High and Half the time Low then its 50% duty cycle. And we can have any percentage of the duty cycle.

So to generate a PWM signal we will use IC555 timer along with some other components shown in the schematic. Here we have controlled the output frequency of the PWM signal by selecting resistor Potentiometer P1 and capacitor C1

Here is the formula to calculate the desired frequency,

Frequency = 1.44 / (R1 * C1)

And Duty cycle will be controlled as we rotate the P1

Schematic_IC555_Sheet_2_20190809210311.pdf
Download

Step 3: Let's Built It!

So, lets first built this circuit on a breadboard an see if it works,

After hooking up my Oscilloscope we can see the PWM,

Since this schematic is really usefully for application like controlling the Speed of motor and Dimming LED, I converted my Schematic to a PCB and ordered my PCBs through www.JLCPCB.com

who are also the Sponsor of this Turorial, you can order your PCBs only for $2 from their website, they provide PCB service for 2 to 6 layers PCB at insanely low prices and now you can also choose any color solder mask for no extra cost which is really nice, you can also monitor the production in progress with videos, check them out link - www.JLCPCB.com for Sponsoring this project, You can order 2 layer PCB (10cm*10cm) only for $2 from their website. Built time for 2 layers PCB is only 24Hr with any color solder mask.