×

Load short-circuit detection using AWH-bridge driving circuit and an exclusive-OR gate

  • US 5,457,391 A
  • Filed: 08/23/1993
  • Issued: 10/10/1995
  • Est. Priority Date: 09/03/1992
  • Status: Expired due to Fees
First Claim
Patent Images

1. A load short-circuit detection circuit, comprising:

  • an H-bridge-type load driving circuit provided with first through fourth input terminals to which first through fourth drive signals are supplied for driving an inductive load with an alternating current, and X and Y terminals between which the inductive load is connected;

    a first transistor a base of which is connected to the X terminal and a collector of which is supplied with a first voltage;

    a first resistor one terminal of which is connected to an emitter of the first transistor;

    a first constant current source connected to the other terminal of the first resistor;

    a second transistor a base of which is connected to the Y terminal and a collector of which is supplied with a second voltage;

    a second resistor one terminal of which is connected to an emitter of the second transistor;

    a second constant current source connected to the other terminal of the second resistor;

    a comparing circuit for receiving a voltage of a node between the first resistor and the first constant current source and a voltage of a node between the second resistor and a second constant current source, comparing the received voltages and outputting a signal with a level corresponding to a comparison result;

    an exclusive OR gate circuit, coupled to one of said first to fourth terminals and to said comparing circuit, for receiving one of the first through fourth drive signals and the signal outputted from the comparing circuit and executing an exclusive OR operation on said one of the drive signals and said outputted signal.

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