Building an AC Power Switch Development Board

Ever want to create a design that automates turning on or off an AC powered device such as a light or a heating system? Well this video is for you! In this video we look at how to create a development board for switching on and off AC power. The switch is implemented with a TRIAC which is a semiconductor device so no moving parts like a relay based design. You can access the Eagle PCB layout files from this link https://github.com/ForceTronics/AC-Switch-Proto-Board/tree/master or you can purchase this development board from www.forcetronics.com

Download Eagles files from GitHub: https://github.com/ForceTronics/AC-Switch-Proto-Board

*********************************Arduino code shown in the video********

//This sketch is used to control Thyristor that is used as a switch to turn on and off an AC line powered light. //This code is free for all to use

int8_t dig = 0; //default is high for light off

void setup() {

  //for controlling Thyristor

  pinMode(7, OUTPUT); //set pin to output so it can sink current from optoisolator

  digitalWrite(7, HIGH); //when high the thyristor is off or open

}

void loop() {

  delay(3000); //light turns on / off every 2 seconds

  togLight(); //call function to turn light on / off using digital pin

}

void togLight() {

  if(dig) { 

     digitalWrite(7, HIGH); //turn off light

     dig = 0; //toggle dig value

  }

  else {  

     digitalWrite(7, LOW); //turn light on

     dig = 1; 

   }

}

How to Use a MOSFET as a Switch

In this video we will cover:

• What is a MOSFET
• MOSFET switch vs mechanical switch
• How to use MOSFET as a switch
• Go over example using a MOSFET as a switch with Arduino

Arduino Code********************************************************************

//This example code was used on the Forcetronics YouTube Channel to demonstrate how to use 

//A MOSFET as a switch. The code is open for anybody to use or modify

const int nMOS = 2; //create variable for n channel MOSFET pin

const int pMOS = 3; //create variable for p channel MOSFET pin

void setup() {

  pinMode(nMOS, OUTPUT);   // set pin to output

  pinMode(pMOS, OUTPUT);   // set pin to output

}

void loop() {

  digitalWrite(nMOS, HIGH);   // set n MOSFET gate to high, this will turn it on or close switch

  digitalWrite(pMOS, HIGH);   // set p MOSFET gate to high, this will turn it off or open switch

  delay(750);

  digitalWrite(nMOS, LOW);    // set n MOSFET gate to low, this will turn it off or open switch

  digitalWrite(pMOS, LOW);    // set p MOSFET gate to low, this will turn it on or close switch

  delay(750);

}