Patent ID: 8204658

Claim:
An automatic transmission control apparatus that changes transmission gear ratios of a transmission mechanism by use of a motor, the automatic transmission control apparatus comprising: a motor control apparatus that receives a voltage from a DC power source and controls the motor; a motor voltage detection unit that detects the voltage supplied to the motor control apparatus; a control apparatus voltage detection unit that detects a voltage supplied from the DC power source to the automatic transmission control apparatus; a drive duty calculation unit that calculates a motor drive voltage by utilizing a voltage, as a reference voltage, that is detected by the motor voltage detection unit, and calculates a motor drive duty, based on the calculated motor drive voltage and a duty reference voltage; and a voltage determination unit that determines which one of a voltage detected by the control apparatus voltage detection unit and a voltage detected by the motor voltage detection unit is utilized as the duty reference voltage, wherein the motor control apparatus controls the motor, based on a motor drive duty that the drive duty calculation unit calculates by use of a voltage determined by the voltage determination unit.