×

Power supply circuit for an automobile

  • US 5,191,500 A
  • Filed: 09/11/1990
  • Issued: 03/02/1993
  • Est. Priority Date: 09/12/1989
  • Status: Expired due to Fees
First Claim
Patent Images

1. A power supply circuit for an automobile comprising:

  • an electric automotive appliance;

    a main battery for supplying power to said electric automotive appliance;

    a backup battery for supplying power to said electric automotive appliance;

    an ignition key switch connected between said main battery and said electric automotive appliance;

    battery switching circuit means for connecting one of said main battery and said backup battery to said electric automotive appliance in accordance with a condition of said ignition key switch;

    power detecting means for detecting a charged power in said backup battery;

    operation limitation means for limiting an operation of said electric automotive appliance to substantially reduce an amount of power required by said electric automotive appliance; and

    control unit means for activating said operation limitation means when said power detecting means detects that a charged power in said backup battery is below a predetermined level.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×