A power-source protection circuit includes a power source including a first voltage rail and a second voltage rail, a pass switch connected across the first voltage rail and a third voltage rail, a control switch connected to the second voltage rail and a control terminal of the pass switch, such that the pass switch turns on in response to the control switch turning on and the pass switch turns off in response to the control switch turning off, and output terminals connected to the third voltage rail and the second voltage rail. The control switch is arranged to switch on when the power source is started and the control switch is arranged to switch off when the output terminals are short-circuited and to switch on when the short-circuit is removed.