Power control system for car computer

A power control system for car computer, comprising:

• a computer host;
• a power switching circuit provided between a power input terminal of the computer host and an external power source;
• whereby when a key power is turned on and supplied to the computer host, the computer host outputs a keep-power-on signal;
• a power ON/OFF circuit provided between the power switching circuit and the external power source;
• the power ON/OFF circuit receiving the keep-power-on signal output by the computer host to thereby connect the external power source to the power input terminal of the computer host to form a close circuit;
• a key power detection circuit for detecting from time to time whether the key power is in the ON state, and outputting a detected result to the computer host, so that the computer host may output a shut-down signal when the key power is detected as OFF;
• a computer shut-down circuit for receiving the shut-down signal output by the computer host and thereby driving the computer host to execute shut-down procedures;
• and
• a power OFF circuit for sensing an OFF state of the key power, and outputting a control signal to drive the power ON/OFF circuit to disconnect the external power source from the computer host.