| 摘要 |
PROBLEM TO BE SOLVED: To provide an open-phase detection device for driving a sensorless DC brushless motor for intentionally stopping a motor and preventing electric leak from a disconnection point, by detecting disconnection of a power supply line to the motor or disconnection of a coil inside the motor, by detecting current that flows to a comparison part from a neutral point.SOLUTION: An open-phase detection device for driving a sensorless DC brushless motor includes an inverter circuit 3 which sequentially applies power to respective coils of a motor 1, a comparison part 5 for comparing an induction voltage that occurs at each coil with a neutral voltage, a control signal generating part 6 for driving the inverter circuit 3, and a control voltage generating part 7. It further includes a current detection part 9 which detects current that flows to the comparison part 5 from the neutral point and outputs a voltage value, a reference voltage division part which divides the control voltage into a predetermined division voltage value, an open-phase comparison part 11 for comparing the voltage value with the division voltage value, and a power cut-off part 13 which cuts off power supply to the inverter circuit 3 according to the open-phase comparison result. |
