Abstract

The method is for making an electric motor more efficient by iteratively changing when a processor sends activation signals to transistors (Q1, Q2) to minimize a current required to rotate a rotor (16) at a constant rotational speed. The method is also for changing a rotational direction of the rotor (16) by switching the order in which activation signals are sent to the transistors (Q1, Q2).

IPC Classes  ?

• H02P 1/00 - Arrangements for starting electric motors or dynamo-electric converters
• H02P 1/28 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor by progressive increase of voltage applied to primary circuit of motor
• H02P 1/38 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor by pole-changing
• H02P 1/52 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual synchronous motor by progressive increase of frequency of supply to motor
• H02P 4/00 - Arrangements specially adapted for regulating or controlling the speed or torque of electric motors that can be connected to two or more different electric power supplies
• H02P 7/06 - Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current
• H02P 7/28 - Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices

Abstract

The method is for making a brushless direct-current (DC) motor quieter. A predetermined high frequency pulse width modulated (PWM) signal is generated. The PWM signal is sent to a first filter (34, R3, R4, C11, C12, D8, D9). The first filter truncates the PWM signal to provide the PWM signal with a rise time (102). The rise time allows transistors (Q1, Q2) connected thereto to open smoothly. A second filter (28) is provided that has a non-polarized capacitor (C9, C10, C20, C21). In a coil switching process, the non-polarized capacitor operates as a voltage or current absorption circuit between driving transistors (Q1, Q2). The coil switching process creates transient energy of voltage transients. The non-polarized capacitor (C9, C10, C20, C21) absorbs the transient energy.

IPC Classes  ?

• H02P 9/08 - Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation
• H02P 9/10 - Control effected upon generator excitation circuit to reduce harmful effects of overloads or transients, e.g. sudden application of load, sudden removal of load, sudden change of load
• G08C 19/44 - Electric signal transmission systems using dynamo-electric devices of which only the rotor or the stator carries a winding to which a signal is applied, e.g. using step motor having more than three stator poles