DRIVING DEVICE OF SENSORLESS BRUSHLESS MOTOR

• Main Authors: SAIKI KOICHI, EIHATA YUKIMA, OTOGAWA MASAYA
• Format: Patent
• Language: English
• Published: 09.08.2012
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PROBLEM TO BE SOLVED: To provide a driving device of a sensorless brushless motor, capable of detecting an induction voltage that is no reduction by a three-phase independent method, detecting a rotational position with high precision to allow low rotation driving, and suppressing increase in cost.SOLUTION: A driving device 1 of a sensorless brushless motor 9 includes a power supply circuit (inverter circuit 2) which supplies a power supply voltage Vcc to terminals 95U, 95V, and 95W of three-phases of an armature winding, a position detection circuit 3 which detects a rotational position based on an induction voltage VSw at the terminal, and a power supply control circuit 4 which controls timing in an electrification time zone based on the rotational position. The position detection circuit 3 includes a selecting switch 33 which selects and outputs an induction voltage in any one phase, a comparator 34 which compares the induction voltage in any one phase with a predetermined reference voltage for magnitude and outputs a comparison result, and a position detection part 37 which detects a reference rotational position of a rotor by using a change timing of the comparison result.