A 16-channel relay board that lets an Arduino Mega or other 5V controller switch sixteen separate circuits on and off independently. Each relay handles up to 10A at 250VAC, every input goes through an optocoupler, and the inputs are low-level trigger: pull a pin low to switch its relay on.
Only need a few circuits? See the 4-Channel 5V Relay Module. Using an ESP32 or Pico? The 1-Channel 3.3V Relay Module is made for 3.3V boards.
Specifications
Datasheets
What's in the box
Assembled board with screw terminals and input header fitted.
Great for
Wiring & getting started
- Power the board
Connect a regulated 5V DC supply rated 2A or more to the power terminal, following the polarity printed beside it. Join its ground to your controller's ground. Do not power it from an Arduino 5V pin or a USB port.
- Connect the inputs
Run one controller output to each IN terminal you use on the header (IN1 to IN16). In your code, write each pin HIGH before setting it as an output, so the relays stay off while the controller starts.
- Test each channel
With nothing on the contacts, pull each input low in turn. That relay should click and its indicator light, and its COM should connect to NO. When released, COM connects to NC.
- Connect the loads
Turn everything off. Run each load circuit through its channel's COM and NO to switch it on when triggered, or COM and NC to switch it off when triggered. Stay within the load limits on every channel.
Note: Mains voltage can kill. Only wire mains loads if you are competent to do so, fully enclose the board so no terminal or solder joint can be touched, and follow NZ electrical safety rules. Motors and lamps draw a surge at switch-on, so leave margin below the limits.