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METHOD AND APPARATUS FOR DETECTING REVERSE CURRENT, AND METHOD AND APPARATUS FOR DRIVING MOTOR

  • US 20090218972A1
  • Filed: 02/20/2009
  • Published: 09/03/2009
  • Est. Priority Date: 03/03/2008
  • Status: Abandoned Application
First Claim
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1. A method for detecting a reverse flow of a phase current supplied to a motor coil from a node between a higher power supply-side transistor and a lower power supply-side transistor, which are connected in series with each other to form a half bridge, by driving the half bridge under a PWM control, the method comprising the steps of:

  • determining whether an electrical conduction control to the motor coil is in a predetermined state based on a timing signal representing a timing at which to conduct a source current or a sink current through the motor coil and a control signal for the half bridge;

    comparing a voltage at the node with a threshold value;

    determining whether the voltage at the node is shifted from an ideal value in the predetermined state based on a result of the comparison; and

    determining that the phase current is reversed if it is determined that the electrical conduction control to the motor coil is in the predetermined state and if it is determined that the voltage at the node is shifted from the ideal value.

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