POWER CONTROL SYSTEM FOR CAR COMPUTER

• US 20080301481A1
• Filed: 06/04/2007
• Published: 12/04/2008
• Est. Priority Date: 06/04/2007
• Status: Active Grant

• Current Assignee: King Technology Incorporated
• Original Assignee: King Technology Incorporated
• Inventors: CHENG, Ta-Yang
• Granted Patent: US 7,894,954 B2
• Time in Patent Office: Days
• US Class Current: 713/323
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

A power control system for car computer includes a power switching circuit located between a power input terminal of a computer host and an external power source, such that the computer host outputs a keep-power-on signal when a key power is supplied thereto; a power ON/OFF circuit receiving the keep-power-on signal to thereby connect the external power source to the computer host; a key power detection circuit for constantly detecting whether the key power is ON, so that the computer host outputs a shut-down signal when the key power is OFF; a computer shut-down circuit for receiving the shut-down signal from 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.

Claims

1. 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.

2. The power control system for car computer as claimed in claim 1, wherein the external power source is a car battery power source.

3. The power control system for car computer as claimed in claim 1, wherein the power switching circuit is located before the power input terminal of the computer host, and is forward connected to the key power via a first diode, and to the external power source via another diode parallelly connected to the first diode.

4. The power control system for car computer as claimed in claim 1, wherein the computer shut-down circuit includes a first transistor switch connected to a pin GPO1 and a power ON/OFF of the computer host as well as to a grounding capacitor, and the grounding capacitor is connected to the key power detection circuit via a resistor and a diode.

5. The power control system for car computer as claimed in claim 4, wherein the computer shut-down circuit further includes a second transistor switch connected between the power ON/OFF circuit and the computer host.

6. The power control system for car computer as claimed in claim 5, wherein the power OFF circuit includes a diode connected to the key power, the diode is connected via a resistor to a grounding capacitor and an inverter, and the inverter is connected via a transistor switch to the transistor switch of the power ON/OFF circuit and the second transistor switch of the computer shut-down circuit.