Abstract: It is presented a power control device. The device comprises a power input; a power output; a switch arranged between the power input and the power output to thereby control power supply on the power output; a controller connected to the switch, the controller having a signal input; and a timer arranged to run when power is supplied on the power output. The controller is arranged to, when the timer reaches a predetermined value, control the switch to disconnect, and the controller is arranged to, when a heartbeat signal is received on the signal input, reset the timer.