Protection circuit for hard disk

Abstract

A protection circuit includes a switch circuit, a sample circuit, a comparison circuit, and a relay circuit. The switch circuit is connected between a hard disk power supply and a hard disk to control whether to output power from the hard disk power supply to the hard disk. The sample circuit samples the voltage being supplied to the hard disk, the comparison circuit receives the sampled voltage, compares the sampled voltage to a reference voltage, and controls the switch circuit to be turned on or off accordingly. The relay circuit is connected between a system power supply and an enable terminal of the comparison circuit. The relay circuit outputs a high level signal to turn on the switch circuit when the system power supply is being supplied and the hard disk power supply is not being supplied to the hard disk.

Dependencies are inferred from the claim text.