Simplified power system with a single power converter providing low power consumption and a soft on/off feature

• US 5,530,878 A
• Filed: 11/17/1994
• Issued: 06/25/1996
• Est. Priority Date: 11/17/1994
• Status: Expired due to Fees

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Ng, Wah K., Bauer, Robert M.
• Primary Examiner(s): Ray, Gopal C.
• Application Number:
  US08/341,438
• Time in Patent Office: 586 Days
• Field of Search: 395/750, 364/707, 365/229, 365/226, 365/227, 307/66, 377/16
• US Class Current: 713/310
• CPC Class Codes: G06F 1/305 in the event of power-supply fluctuations

Abstract

A computer power system with a keyboard, a computer housing, and a single AC to DC power converter that generates a DC power signal as long as it is energized by an AC power source. The power system is digitally controllable by the central processing unit (CPU) or from soft on/off switches on the keyboard and computer housing. This is made possible by a soft on/off controller that receives soft on/off control signals from the CPU and the soft on/off switches and in response generates a power transition signal that triggers shaping circuits to connect (soft on) or disconnect (soft off) power system output lines and power lines from the converter. The shaping circuits also ensure that the rising edge of a digitally switched power system output signal resembles the rising edge of the converter'"'"'s cold-start power signal. Following a soft off event,, the power system is in a low power standby state as power is not being supplied to the computer'"'"'s power hungry components even though the converter is still generating a power signal.

Claims

1. A power system for a computer, the system comprising:

a keyboard with a first selectable digital control switch;

a computer housing with a second selectable digital control switch;

an AC to DC power converter that generates a DC power signal as long as said converter is energized by an alternating current power source, said DC power signal having a gradual rising edge upon a cold power start of said computer, said power converter alone supplying said computer with power when said power system is in a state selected from a standby state or an operational state;

a soft on/off controller for generating a power transition signal in response to operation of at least one of said first and second digital control switches, said power transition signal triggering a transition of said power system between said standby state and said operational state; and

shaping circuitry, coupled to said AC to DC power converter and said soft on/off controller, responsive to said power transition signal and said DC power signal to generate upon transition from said standby state to said operational state an output signal having a leading edge, wherein Said leading edge of said output signal is shaped to resemble said DC power signal'"'"'s rising edge upon a cold power start of said computer, said output signal and not said DC power signal being used to power components of said computer.

2. The power system from claim 1 wherein said on/off controller is responsive to a CPU soft off signal generated by a central processing unit (CPU) that is part of said computer.

3. The power system from claim 1 wherein power consumption by said computer following completion of a soft off event is substantially less than power consumption by said computer following completion of a soft on event.

4. A power system for a computer, the system comprising:

at least one selectable digital control switch;

an AC to DC power converter that generates a DC power signal as long as said converter is energized by an alternating current power source, said DC power signal having a gradual rising edge upon a cold power start of said computer, said power converter alone supplying said computer with power when said power system is in a state selected from a standby state or an operational state;

a soft on/off controller for generating a power transition signal in response to operation of said at least one digital control switch, said power transition signal triggering a transition of said power system between said standby state and said operational state; and

shaping circuitry, coupled to said AC to DC power converter and said soft on/off controller, responsive to said power transition signal and said DC power signal to generate upon transition from said standby state to said operational state an output signal having a leading edge, wherein said leading edge of said output signal is shaped by said shaping circuitry to resemble said DC power signal'"'"'s rising edge upon a cold power start of said computer, said output signal and not said DC power signal being used to power components of said computer.

5. A method for digitally controlling a power system

for a computer, said method comprising the steps of:

generating at least one soft on/off signal by operating at least one of a first selectable digital control switch on a keyboard and a second selectable digital control switch on a computer housing;

outputting from an AC to DC power converter a DC power signal as long as said power converter is energized by an alternating current power source, said DC power signal having a gradual rising edge upon a cold power start of said computer, said power converter alone supplying said computer with power when said power system is in a state selected from a standby state or an operational state;

outputting a power transition signal from a soft on/off controller in response to said at least one soft on/off signal, said power transition signal triggering a transition of said power system between said standby state and said operational state; and

generating from said DC power signal and in response to said power transition signal triggering a transition from said standby state to said operational state an output signal having a leading edge, and shaping said leading edge of said output signal to resemble said DC power signal'"'"'s rising edge upon a cold power start of said computer, said output signal and not said DC power signal being used to power components of said computer.

6. A power system for a computer, the system comprising:

a keyboard with a first selectable digital control switch;

a computer housing with a second selectable digital control switch;

an AC to DC power converter that generates a DC power signal as long as said converter is energized by an alternating current power source, said DC power signal having a gradual rising edge upon a cold power start of said computer, said power converter alone supplying said computer with power when said power system is in a state selected from a standby state or an operational state;

a soft on/off controller for generating a power transition signal in response to operation of at least one of said first and second digital control switches, said power transition signal triggering a transition of said power system between said standby state and said operational state; and

shaping circuitry, coupled to said AC to DC power converter and said soft on/off controller, responsive to said power transition signal and said DC power signal to generate upon transition from said standby state to said operational state an output signal having a leading edge, wherein said leading edge of said output signal is shaped to resemble said DC power signal'"'"'s rising edge upon a cold power start of said computer, said output signal and not said DC power signal being used to power components of said computer;

wherein said soft on/off controller accords higher priority to said operation of said second selectable digital control switch than to said operation of said first selectable digital control switch, such that when the power system is in its operational state, activation of said second selectable control switch causes said soft on/off controller to transition the power system to its standby state regardless of status of said first selectable digital control switch.

7. A method for digitally controlling a power system for a

computer, said method comprising the steps of:

generating at least one soft on/off signal from at least one selectable digital control switch;

outputting from an AC to DC power converter a DC power signal as long as said power converter is energized by an alternating current power source, said DC power signal having a gradual rising edge upon a cold power start of said computer, said power converter alone supplying said computer with power when said power system is in a state selected from a standby state or an operational state;

outputting a power transition signal from a soft on/off controller in response to said at least one soft on/off signal, said power transition signal triggering a transition of said power system between said standby state and said operational state; and

generating from said DC power signal, in response to said power transition signal triggering a transition from said standby state to said operational state, an output signal having a leading edge and shaping said leading edge of said output signal to resemble said DC power signal'"'"'s rising edge upon a cold power start of said computer, said output signal and not said DC power signal being used to power components of said computer.