Motor Speed Controller Using Triac

Simple Ac Motor Speed Control Circuit Using BT136 Triac

This Ac Motor speed controller circuit is working based on the Triac and Diac. You can use household equipment like a drilling machine to control the rotating speed of it.

BT136
BT136 triac

The speed of the electric motor adjusted by rotating the preset pot on the board. Rotate the preset pot to left side right side to increase the speed and left to decrease the speed.

motor speed controller schematic
motor speed controller schematic

This motor speed control circuit diagram contains few components such as:

  • BT136 Triac
  • DB3 diac
  • 0.1 uf 400v capacitor
  • 500k pot
  • 10k resistor
  • Ac input and output connector

The motor speed control board also included in this article. you can able to access this free PCB layout without any cost.

ac motor speed controller pcb
Ac motor speed control board

Working of Ac motor controller

This circuit is working based on the triac of Bt 136. It is having the maximum terminal current is 4A. so you can only use up to 800watts electric equipment to control.

A proper heat sink must be fitted with Bt136 triac. Because the haet should be produced during the working of the motor controller.

Adjusting the preset pot will regulating the input voltage to the triac. so the triac will allow the ac voltage with the controlled manner. This is the main principle of this circuit.

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Akhil Satheesh

Akhil Satheesh

👋 Hello there! I'm Akhil Satheesh, Founder and CEO of Solderingmind.com. I am an expert in building innovative electronic circuit and PCB designing. Most of the tested electronic projects are sharing with you.

One comment

  1. This didn’t work for me.
    It looked fine with a bulb, but the triac failed short circuit the first time I connected a 400W motor.

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