This is 8 Channel 5V Solid State Relay Module. A solid state relay (SSR) is just what it sounds like; an IC that acts like a mechanical relay. They allow you to control high-voltage AC loads from lower voltage DC control circuitry. They accomplish this by using infrared light as the ‘contact,’ a solid-state relay is really just an IR LED and a photo triac sealed up into a little box. Solid state relays have several advantages over mechanical relays. A Solid State Relay is similar to a mechanic relay where it can be controlled through a digital signal. Solid State Relay generates no noise and has a much longer lifespan in compared to the traditional mechanic relay. One such advantage is that they can be switched by a much lower voltage and at a much lower current than most mechanical relays. Also, because there are no moving contacts, solid state relays can be switched much faster and for much longer periods without wearing out. Input Parts : DC : connected to VCC (Supply power according to relay voltage) DC-: connected to GND IN1: CH1 Signal triggering the end of 1-channel relay module (active at the high level) IN2: CH2 Signal triggering the end of 2-channel relay module (active at the high level) IN3: CH3 Signal triggering the end of 3-channel relay module (active at the high level) IN4: CH4 Signal triggering the end of 4-channel relay module (active at the high level) IN5: CH5 Signal triggering the end of 5-channel relay module (active at the high level) IN6: CH6 Signal triggering the end of 6-channel relay module (active at the high level) IN7: CH7 Signal triggering the end of 7-channel relay module (active at the high level) IN8: CH8 Signal triggering the end of 8-channel relay module (active at the high level) Operating current : 1 WAY:13.8mA 2 WAY: 26.8mA 3 WAY: 37mA 4 WAY: 48mA 5 WAY: 59mA 6 WAY: 70mA 7 WAY: 81mA 8 WAY: 90mA Features : 8-channel 2 AMP Solid State Relay board. Control 8 loads of up to 2 amps each at 120 V or 240 V AC. Good for lighting, Holiday displays etc. Has been assembled, and the electrical test passed. Led indicator for each relay. Use it to control various appliances and other equipment with large current. It can be controlled directly by Microcontroller Input control signal voltage. 0-0.5V low stage SSR is OFF 0.5V – 2.5V (unknown state). 2.5-20V high stage SSR is ON Package Includes : 1 x 8 Channel 5V Solid State Relay Module Board OMRON for Arduino. SKU: PGI-0043107 Category: Relay