This relay module can be used to control a high voltage AC device from a lower voltage DC micro-controller/microcomputer such as Raspberry Pi, Beaglebone Black, Arduino, PIC etc.
A Solid State Relay (SSR) like this has several advantages over mechanical relays. It has no moving parts at all hence it can last longer than a mechanical relay. There is no clicking sound that you often heard on mechanical relays. On the other hand, this SSR can only switch AC unlike some mechanical relays that can switch both AC and DC. It also require minimum load or it can't function.
This board has 2 high-trigger relays, a screw terminal for input to control the relays and another screw terminal for output (normally open). At the input terminal, you have to connect 5V DC and GND to DC+ and DC- respectively. The CH1 and CH2 terminals are used to trigger the relay. Since this is a high-level trigger module, any voltage between 3.3V-5V applied will trigger the relay. This is indicated by two status LEDs on board.
The output terminal is where you connect your load. Each relay has two normally open terminals. When the relay is triggered, these two will make contact (close).
Warning: Mains electricity can kill you. Please consult with a licensed electrician if you are working with the mains!
Features:
5V 2-channel solid state relay board
Operating voltage: 4V to 6V DC
5V relay control signal voltage (Range: 0-5V)
HIGH (3.3V-5V) on input terminal (CH1/CH2) will switch the relay, 2mA trigger current
Rated output load: 250V AC 2A
Screw terminals for input control signal and relay contact
