control high voltage devices arduino relay tutorial

Output Terminals:ĬOM terminal connects to the device you intend to control. Keep this pin disconnected if you remove the jumper. VCC pin is shorted to the JD-VCC pin with the jumper cap on. Without the jumper cap, you’d have to connect it to a separate 5V power source. When the jumper is in place, JD-VCC is shorted to VCC, allowing the electromagnets to be powered by the Arduino’s 5V line. JD-VCC provides power to the relay’s electromagnet. These are active low pins, which means that pulling them LOW activates the relay and pulling them HIGH deactivates it. VCC pin provides power to the built-in optocouplers and, optionally, the relay’s electromagnet (if you keep the jumper in place). Here’s a small animation showing how a relay links two circuits together. A relay can be thought of as an electric lever you turn it on with a relatively small current, and it turns on another device with a much larger current. How Do Relays Work?Īt the core of a relay is an electromagnet (a wire coil that becomes a temporary magnet when electricity is passed through it). This tutorial will walk you through setting up the relay module to turn on a lamp or other device, but first, a quick primer on relays. The only downside is that, because these are electro-mechanical devices, they are more prone to wear and tear over time. These well-contained modules are inexpensive, simple to connect, and ideal for home-brew projects that require switching modest amounts of AC or DC power. This is where relay modules come into play. However, because the Arduino runs on 5 volts, it cannot directly control these high-voltage appliances.

In your upcoming project, you might want to use your Arduino to control a high-voltage device, like a lamp, fan, or other household appliance.

Control high voltage devices arduino relay tutorial