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
For safety reasons we DO NOT recommend using this module with voltages above 24V. Any use of this module is at your own risk! Always take necessary safety precautions when working with high voltages to prevent electrical shock! We will take no responsibility for any damage, personal injury or death incurred due to using this unit with high voltages!
Please note these are VERY LOW cost boards from China. If you expect a premium product, this is NOT for you. These boards might have scratches on them, might not be the cleanest, and the packaging might have scratches or small tears. For example, if the board has pin headers, they are often ship to us from China all together in a bag, and the pins might be slightly bent or protrude through the bag. If this is not acceptable, please look for a more premium product. After all our costs (10% GST, over 10% eBay/PayPal fee and "Free" shipping we have to pay for), you can appreciate that there is very, very little profit margin left for us. We bring you these products at a very good price, but keep in mind it is a very low cost, cheap and nasty cheap product - exactly the same as similar price products sold by other sellers.
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)