ITEM NAME:8 Channel 20A Relay Control Module for Arduino UNO MEGA2560 R3 Raspberry Pi Product Description Description: 8 Channel 20A Relay Control Module for Arduino UNO MEGA2560 R3 for Raspberry Pi Descriptions: 1. Bi-directional isolated 8 channel relay control module, according to user's needs. 2. It can choose high or low electrical level to control the pick-up of the relay. 3. The module adopts genuine and high quality power relay, industry top-most ultra small package optocouplers, high power high dielectric transistor, RED signal lights, double side military grade PCB plate, overall consideration layout after overall consideration, with its stable performance. 4. It can be widely used in varieties of power control occasions. Module Instruction: 1. The module adopts genuine and high quality relay, AC 125V/20A, DC 14V/20A. 2. With application of industry top-most ultra small Bi-directional optocouplers, the module has full noises immunity and stable performance. 3. Working voltage of the module is 5V. 4. The users could choose the electrical level of the relay, either the pick-ups occurs in high electrical level or low electrical level; the module contains current-limiting resistance, it can be controlled directly by the positive and negative electrodes of the power source, and also can be controlled by I/O console of the microcontroller. 5. The design of fault tolerant, even if the control wire was broken, yet the relay will take any action. 6. Humanization design of the interface, all the interfaces can be directly lined out through connecting terminals, which is very handy. 7. Providing 4 pieces retaining bolt hole, easy to install. 8. The Relay's status indicator light (red). The module's interface: The module's control end: it has 11 lines of interfaces, all the interfaces can be directly lined out with wire, for the convenience of our users. DC+: Termination connected to positive electrodes of the external direct current power. DC-: Termination connected .With application of industry top-most ultra small Bi-directional optocouplers, the module has full noises immunity and stable performance. NC1-NC8: Normally closed interface of the relay, It short circuits with COM before the relay's pick-up and dangles after the relay's picked-up.