Relay board module is used for controlling higher current loads from your microcontroller development board, PC parallel port or Arduino Uno. This board has one (1) on-board relay which can switch up to 7Amps. Relays terminals (C, NC, NO) are accessible through screw terminals which makes wiring up the board very easy. The relay is safely driven by transistor BC547 hence your input device, such as Arduino, is protected from relay circuit. There is freewheeling diode which will further protect your microcontroller from relay kick back.Single channel 12 volt relay connection are
This is a 12V 1-Channel Relay interface board which can be controlled directly by a wide range of microcontrollers such as Arduino, AVR, PIC, ARM, 8051 and so on.