This modules contains 8 relays, rated at 5V and 10A. Each relay has a LED indicator. It can be used to control various appliances, and other equipment with large current. It can be controlled directly with 3.3V or 5V logic signals from a microcontroller (Arduino, 8051, AVR, PIC, DSP, ARM, ARM, MSP430, TTL logic).
Each relay has an onboard EL817 optocoupler, providing optical isolation. Each relay also have a freewheeling diode protection.
This module has a 11 pin header(standard 2.54mm pitch) for connecting power (5V and GND), and controlling the 8 relays. The pins are marked on the PCB:
IN1 to IN8: Controls relays 1 to 8, active Low! Relay will turn on when this input goes below about 2.0V
COM: Common for relay input, 3.3V or 5V
GND: Connect 0V to this pin. Is used to power the opto couplers.
VCC: Connect 5V to this pin. Is used to power the opto couplers.
Documentation and Wiring
Wiring is very easy, and is shown in the diagram below.
If opto isolation is required, the 5V power supply should be separate from the controller(Arduino, STM32..) power supply, as shown in the picture below. This is the recommended way to use this module!
If no opto isolation is required, the power for the relay module (VCC and GND pins) can be taken from the controller if available. Just ensure the controller can supply enough power for the relay module. Each relay requires about 72mA, so all 8 relays will require about 580mA! Additionally they might introduce noise to the controller power supply, which could cause glitches.
|*** Click to enlarge ***|
- LEDs: 8 LEDs, one for each channel
- Relay Voltage: 5V
- Relay Coil Current: 72mA at 5V per relay
- Relay Out Current: 10A at 250VAC, 10A at 30VDC
- Size: 79.5mm * 71mm
1 x Relay modules, 8 relays (as shown in picture)