Patent ID: 8063589

Claim:
A drive system for multiple motors, comprising: a first motor; a second motor; a motor drive power supply for supplying power to the first and second motors; a first motor drive amplifier connected between the motor drive power supply and the first motor, for driving the first motor, wherein a first overcurrent benchmark value of the first motor drive amplifier is stored in the motor drive power supply; a second motor drive amplifier connected between the motor drive power supply and the second motor, for driving the second motor, wherein a second overcurrent benchmark value of the second motor drive amplifier is stored in the motor drive power supply; a first overcurrent detection apparatus connected between the motor drive power supply and the first motor drive amplifier capable of detecting current through the first motor drive amplifier, and comparing the current value to the first overcurrent benchmark value to output an overcurrent detection signal correspondingly, the first overcurrent detection apparatus comprising: a first resistor; a second resistor connected to the first resistor in series; a third resistor comprising a first end connected to the motor drive power supply; a first digital/analog (D/A) converter for converting the first overcurrent benchmark value of the first motor drive amplifier stored in the motor drive power supply into analog voltage, an input terminal of the first D/A converter connected to the motor drive power supply, and an output terminal of the first D/A converter connected to a second end of the third resistor via the first and second resistors; and a first comparator comprising a first terminal connected to a node between the first and second resistor to receive a first overcurrent detection reference value, and a second terminal connected to the first end of the third resistor to receive current through the first motor drive amplifier, wherein the first overcurrent detection reference value is maintained from dividing the analog voltage by the first and second resistors; wherein the first comparator outputs an overcurrent detection signal in response to the current inputted to the second terminal of the first comparator being more than the overcurrent detection reference value; and a second overcurrent detection apparatus connected between the motor drive power supply and the second motor drive amplifier capable of detecting current through the second motor drive amplifier, and comparing the current value to the second overcurrent benchmark value to output an overcurrent detection signal correspondingly.