Patent ID: 8008881

Claim:
A voltage protecting apparatus for detecting voltage of a motor driver, and adjusting the voltage of the motor driver when in an over-voltage state, the motor driver comprising a direct current power source and a power board, the direct current power source drive a motor via the power board, the voltage protecting apparatus comprising: a switch unit; a voltage transform unit configured to transform an output voltage of the direct current power source to a low voltage; a controller configured to output a pulse width modulation signal according to movement states of the motor and adjust the voltage of the motor driver via the power board; a voltage detector configured to receive the low voltage from the voltage transform unit; and an over-voltage judger configured to receive the low voltage from the voltage detector and compare the low voltage to a predetermined voltage; wherein when the controller outputs a high level signal, the switch unit is turned on, the voltage transform unit transforms the output voltage of the direct current power source to the low voltage and sends the low voltage to the voltage detector, the over-voltage judger receives the low voltage from the voltage detector and compares the low voltage to a predetermined voltage, when the low voltage is greater than the predetermined voltage, the over-voltage judger outputs a control signal to the controller for signaling the controller to control the power board so as to adjust the voltage of the motor driver.