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 Relay connection are
Connect VCC to 12V power supply
Control signal is used to control the relay. If signal will be HIGH (5V) the relay will be switched to NO(Normally Open) and if signal is LOW (0V) the realy will be switched to Normally Connected (NC)
If control signal is high the led will be glow and Vice- versa.

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 Relay connection are
Connect VCC to 12V power supply
Control signal is used to control the relay. If signal will be HIGH (5V) the relay will be switched to NO(Normally Open) and if signal is LOW (0V) the realy will be switched to Normally Connected (NC)
If control signal is high the led will be glow and Vice- versa.