Choose the Right 5V Relay Board Size for Your Project

The Relay Module Channel 5v With Optocoupler Projects Arduino Compatible listing groups several 5V relay board sizes into one product, so you can choose the channel count that matches your build. It is a smart option for makers who want the same relay style across small and large projects.

From a single output to multi-output control panels, this family gives you a familiar 5V relay format with optocoupler protection and Arduino-friendly control.

Why you'll like it

• Several channel options: 1, 2, 4, 6, 8, and 16 channels
• 5V control: Common for maker boards and automation demos
• Optocoupler support: Better protection between logic and relay side
• Consistent board family: Easier to standardize across projects
• Strong all-around use: Good for lights, locks, valves, pumps, and more

What you can build

Use the 1- or 2-channel versions for simple builds, the 4- to 8-channel versions for common automation jobs, and the 16-channel version for denser control panels or larger demonstration systems.

Starter bundles

Pair it with an Arduino-compatible board, ESP32, or Raspberry Pi, plus jumper wires, a suitable power supply, and a small load for bench testing.

Recommended add-ons

Useful add-ons include terminal block, breadboard, power modules, fuses, and enclosure, especially when you are working with higher voltages or inductive loads.

Technical specifications

Relay board size comparison

Pinout & power notes

Most versions use VCC, GND, and one IN pin per relay, with COM, NO, and NC on the output side. Some board revisions also include JD-VCC jumpers for separate relay power setups.

What’s in the box

1 × selected relay module variant

Frequently Asked Questions