Collectorless direct current motor, driver circuit for a drive and method of operating a collectorless direct current motor
First Claim
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1. Driver circuit for a collectorless direct current motor including a permanent magnet rotor having at least two poles and at least one stator winding, comprising:
- a driver circuit end stage connected to the stator winding for temporarily operating as a switch,a sensor for detecting a position of the rotor, said sensor producing sensor signals which are representative of a commutation phase,a control siganl, said control signal being supplied to said driver circuit end stage during each said commutation phase, said control signal causing a ramp-shaped current curve to arise as a function of time in the stator winding,said driver circuit end state having a linkage circuit which is controlled by said control signal and by said sensor signals of said sensor, said linkage circuit producing an end stage control signal whose duration is variable and is less than the duration of a respective one of said sensor signals,said driver circuit end stage including at least one semiconductor element which operates during said commutation phase for a first period of time as a switch and for a second period of time as an analog amplifier, current in said semiconductor element being relatively constant during said first period of time and changing according to a predetermined ramp function during said second period of time.
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Abstract
A method for the low-loss regulation of a collectorless direct current motor and a semiconductor circuit has, during the commutation phase given by a position sensor and with reduced motor output and number of revolutions, transistors or one end transistor which initially operates temporarily as a switch and thereafter operates temporarily as an analog amplifier element. During the analog period, a current is available which changes slowly according to a ramp function.
57 Citations
23 Claims
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1. Driver circuit for a collectorless direct current motor including a permanent magnet rotor having at least two poles and at least one stator winding, comprising:
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a driver circuit end stage connected to the stator winding for temporarily operating as a switch, a sensor for detecting a position of the rotor, said sensor producing sensor signals which are representative of a commutation phase, a control siganl, said control signal being supplied to said driver circuit end stage during each said commutation phase, said control signal causing a ramp-shaped current curve to arise as a function of time in the stator winding, said driver circuit end state having a linkage circuit which is controlled by said control signal and by said sensor signals of said sensor, said linkage circuit producing an end stage control signal whose duration is variable and is less than the duration of a respective one of said sensor signals, said driver circuit end stage including at least one semiconductor element which operates during said commutation phase for a first period of time as a switch and for a second period of time as an analog amplifier, current in said semiconductor element being relatively constant during said first period of time and changing according to a predetermined ramp function during said second period of time. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Collectorless direct current motor for driving a fan, comprising:
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a stator having at least one stator winding; a permanent magnet rotor having at least two poles and being disposed in the field of said at least one stator winding, said at least one stator winding being supplied with an operating voltage by a circuit, said circuit having a position sensing means for detecting a position of said permanent magnet rotor to determine a commutation phase thereof, at least one semiconductor element supplying current to said stator winding, a temperature sensing means for detecting temperature of an air stream drawn by the fan, and a control means for controlling said at least one semiconductor element during said commutation phase based upon the temperature sensed by said temperature sensing means, said at least one semiconductor element included in said circuit being controlled by said control means to operate as a switch for supplying a relatively constant current over a part of the commutation phase and as an analog amplifier element over another part of the commutation phase, said at least one semiconductor element, during a period of time where in a reduction in revolution rate of said permanent magnet rotor occurs, operating initially as a switch and thereafter operating temporarily as an analog amplifier, current in said at least one semiconductor element being reduced during said period of time according to a predetermined ramp function. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification