Power supply and oscillator for a computer system providing automatic selection of supply voltage and frequency
First Claim
1. A power system for providing a supply voltage to a computer system and automatically establishing the magnitude of said supply voltage responsive to the magnitude of the current being supplied to the computer system, said power system comprising:
- supply voltage circuit means for generating said supply voltage at an output terminal, said supply voltage circuit means including a control terminal for receiving a control signal; and
voltage selection circuit means including comparator means having first and second input terminals and an output terminal, first circuit means for generating a reference voltage and coupling said reference voltage to said first input terminal of said comparator means, second circuit means for generating a second voltage having a magnitude proportional to said supply voltage and coupling said second voltage to said second input of said comparator means, means coupling the output of said comparator means to said control terminal of said supply voltage circuit means, and current sensing circuit means having an input coupled to said supply voltage circuit means and an output coupled to said second circuit means, said current sensing circuit means operating to generate at its output a voltage having a magnitude proportional to the supply current, whereby for a supply current equal to or less than a predetermined value, the output from said comparator means controls said supply voltage circuit to cause said supply voltage to be a first value, and for supply currents greater than said predetermined value, the output from said comparator means causes said supply voltage to be a second value.
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Accused Products
Abstract
Disclosed is a power system for use with a computer, the power system having incorporated in it circuitry for automatically varying the supply voltage output to the computer system based upon the magnitude of the current being supplied to the computer by the power system. Also included in the computer system is a variable frequency clock circuit, the frequency of which changes based upon the supply voltage produced by the power system. This permits, during computer system operation where low voltage and low clock speeds will be sufficient to provide the performance needed, achievement of a power saving since both the voltage and frequency at which the system operates is reduced, thereby markedly reducing the power consumption.
246 Citations
15 Claims
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1. A power system for providing a supply voltage to a computer system and automatically establishing the magnitude of said supply voltage responsive to the magnitude of the current being supplied to the computer system, said power system comprising:
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supply voltage circuit means for generating said supply voltage at an output terminal, said supply voltage circuit means including a control terminal for receiving a control signal; and voltage selection circuit means including comparator means having first and second input terminals and an output terminal, first circuit means for generating a reference voltage and coupling said reference voltage to said first input terminal of said comparator means, second circuit means for generating a second voltage having a magnitude proportional to said supply voltage and coupling said second voltage to said second input of said comparator means, means coupling the output of said comparator means to said control terminal of said supply voltage circuit means, and current sensing circuit means having an input coupled to said supply voltage circuit means and an output coupled to said second circuit means, said current sensing circuit means operating to generate at its output a voltage having a magnitude proportional to the supply current, whereby for a supply current equal to or less than a predetermined value, the output from said comparator means controls said supply voltage circuit to cause said supply voltage to be a first value, and for supply currents greater than said predetermined value, the output from said comparator means causes said supply voltage to be a second value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A supply voltage circuit means having an input adapted for connection to a battery for producing at an output terminal supply voltages having a plurality of magnitudes, said supply voltage circuit means having a control terminal for receiving an input signal for controlling the magnitude of the supply voltage produced at said output terminal, voltage selection circuit means having an input circuit for receiving a boost control signal from a computer system and an output circuit coupled to said control terminal of said supply voltage circuit means, and a battery change backup circuit coupled to said output terminal of said supply voltage circuit means, said battery change backup circuit including means for storing a charge, a method of providing maximum supply voltage backup time when said battery is removed comprising the steps of:
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providing an on-off power switch for said computer system to control the output by said supply voltage circuit means of supply voltage to said system; providing means in said computer system responsive to changing said on-off power switch from the on to the off state to produce a boost control signal, and means for coupling said boost control signal to said input of said voltage selection circuit whereby said voltage selection circuit causes said supply voltage circuit means to produce at said output terminal for a predetermined period of time a supply voltage having a magnitude equal to the maximum of the magnitudes provided by said supply voltage circuit means.
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Specification