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Power supply apparatus for efficient power conservation of a battery

  • US 5,528,087 A
  • Filed: 04/20/1993
  • Issued: 06/18/1996
  • Est. Priority Date: 04/23/1992
  • Status: Expired due to Term
First Claim
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1. A power supply apparatus comprising:

  • a battery;

    boosting means for boosting a power voltage from said battery to a boosted voltage which is higher than said power voltage and for supplying said boosted voltage to a memory;

    a back-up power source connected to said boosting means and charged by said boosted voltage, and provided in parallel to said memory for supplying a back-up voltage to said memory;

    comparison means for comparing said back-up voltage with a reference voltage, said comparison means generating an output signal when said back-up voltage is lower than said reference voltage;

    switching means provided between said battery and said boosting means for coupling and uncoupling said battery with said boosting means;

    a power supply switch for indicating a power ON condition and a power OFF condition; and

    switching control means, responsive to said comparison means and said power supply switch and controlling said switching means, for activating said switching means to couple said battery with said boosting means when said power supply switch indicates said power ON condition, and for activating said switching means to intermittently couple said battery with said boosting means for only a predetermined period of time in accordance with said output signal of said comparison means after said power supply switch indicates said power OFF condition.

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