modify the brightness of an LED

Do you wish to modify the brightness of your Gentle-Emitting Diode (LED)? If we break it all the way down to probably the most fundamental, there are two methods to vary the brightness of an LED:

  • Altering the resistance worth.
  • Turning it on and off quick (Utilizing PWM).

Beneath I’ll clarify the 2 choices and present you circuits you’ll be able to construct.

Arduino Shield Project LED matrix

Possibility 1: Change the resistor worth

The brightness of an LED is determined by the present by means of it. A resistor in sequence with the LED units the present. Within the circuit under, you’ll be able to see the essential setup for controlling an LED:

Circuit with LED and resistor

A potentiometer is a variable resistor that you should utilize to vary the brightness of the LED. Simply add the potentiometer in sequence with the LED. While you modify the knob of the potentiometer, the brightness of the LED will change.

Adjusting LED brightness using a potentiometer

Possibility 2: Flip it on and off quick (PWM)

One other methodology is to show the LED on and off quick. Possibly a couple of hundred occasions per second. Normally, you wish to use a microcontroller for this. By adjusting the proportion the LED is on versus off, it can seem to the attention that the brightness adjustments.

This methodology known as Pulse-Width Modulation (PWM).

It’s additionally potential to create a PWM sign with a 555 timer. Right here’s a pattern circuit:

555 Timer PWM circuit with fixed frequency

SW1 is an optionally available button that you should utilize to have two totally different responsibility cycles. I used it to regulate a servo motor in two totally different positions.

Word that the responsibility cycle can’t be decrease than the responsibility cycle of the primary 555 Timer (that units the frequency). So be sure to use parts which have low sufficient OFF time for the responsibility cycle you wish to use


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