Power control unit for a computer system

• US 4,857,756 A
• Filed: 03/11/1988
• Issued: 08/15/1989
• Est. Priority Date: 03/17/1987
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Haneda, Isamu
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Paul
• Application Number:
  US07/166,650
• Time in Patent Office: 522 Days
• Field of Search: 307/64, 307/66, 307/83, 307/84, 307/85, 307/87, 365/226-229, 361/92, 361/91, 361/93, 361/89, 361/87, 361/90
• US Class Current: 307/66
• CPC Class Codes: G05F 1/577 for plural loads
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

Where a system including a main computer with a source battery for generating a system source voltage and a peripheral device having higher operating voltage than the system source voltage and a source voltage generator circuit which generates a source voltage corresponding to this operating voltage, supply of system source voltage from the source battery is prohibited and the source voltage from the source voltage generator circuit of the peripheral devices is used as the system source voltage of the entire system when the main computer is driving the peripheral device such that the consumption of the source battery for the main computer can be reduced.

Claims

1. In a power control unit for controlling the electrical power source of a system including a main computer with a source battery for generating a system source voltage and a peripheral device having a higher operating voltage than said system source voltage and a source voltage generator circuit which generates a source voltage corresponding to said operating voltage, the improvement wherein

said power control unit comprises

a first voltage generating means connected to a system bus for generating a lower voltage,

a second voltage generating means for generating a higher voltage,

a control means serving to output a high output signal or a low output signal, depending on whether an output of power at said higher voltage through said system bus is desired or not,

a first transistor having the base thereof connected to said control means and the emitter thereof grounded, and

a second transistor having the base thereof connected to the collector of said first transistor, the emitter and the base thereof connected to said second voltage generating means and the collector therof connected to said system bus.

2. The power control unit of claim 1 further comprising a capacitor connected between said first voltage generating means and said second voltage generating means for removing noise.