Patent ID: 7613002

Claim:
A heat dissipation device for a hard disk drive of a computer system, comprising: a first heat sink having a cooling end made with a material that cools when a control signal is applied thereto for dissipating heat generated by the hard disk drive; and a control circuit for controlling the first heat sink by applying the control signal to the heat sink material, the control circuit comprising: an input interface for receiving an input signal, which is determined by temperature of the computer system, the input signal in a form of a plurality of pulses; a counter unit for counting the pulses of the input signal, and generating a high level signal on counting to a predetermined value; a controller unit for generating a switch signal on receiving the high level signal, and sending a clear signal to the counter unit for clearing the counter unit; and an output unit for being switched on or off according to the switch signal, and sending the control signal to the first heat sink, the control signal being able to drive the cooling end of the first heat sink to cool down a second heat sink being configured for conducting heat generated by the hard disk drive and contacting the cooling end of the first heat sink at two ends thereof.