Drive circuit for brushless DC motors
First Claim
1. Drive circuit for brushless dc motors with a rotor and with a stator with stater coil, with a commutator device that feeds or interrupts power, specified moments of commutation, in a positive or negative direction, to the stator coil as a function of the rotor angle of rotation with a device to measure the motor speed, characterized in that a device (93) is provided for shifting the moments of commutation. according to phase argle, said device performs the shifting of the moments of commutation as a function of a current, measured motor speed according to a specified function.
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Abstract
A drive circuit for brushless DC motors including a rotor and a stator with at least one stator coil includes a commutation device which supplies commutation pulses of drive current to the stator coil(s). The commutation device senses the rotor position and calculates current rotor speed therefrom. The rotor speed is then used to shift the commutation circuits according to predetermined functions. The shifting of commutation currents is occasioned by shifting either or both of the ignition part of a commutation pulse and the extinction part of such pulse.
24 Citations
31 Claims
- 1. Drive circuit for brushless dc motors with a rotor and with a stator with stater coil, with a commutator device that feeds or interrupts power, specified moments of commutation, in a positive or negative direction, to the stator coil as a function of the rotor angle of rotation with a device to measure the motor speed, characterized in that a device (93) is provided for shifting the moments of commutation. according to phase argle, said device performs the shifting of the moments of commutation as a function of a current, measured motor speed according to a specified function.
- 2. Drive circuit for brushless dc motors with a rotor and with a stator that has at least one stator coil, with a commutation device that feeds current or interrupts current, in a positive or negative direction, to at least one stator coil as a function of the rotational position of the rotor, characterized in that a device (93) for shifting the moments of commutation according to phase angle is provided, where said device undertakes the shifting of the moments of commutation as e function of a preset, estimated or extrapolated motor speed according to a specified function.
Specification