DC Motor driving circuit
AssigneeSony Corporation
InventorFumiyoshi Abe
Life of this patent
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Abstract
A brush-less dc motor driving circuit is disclosed, wherein a variable constant current source is connected in series with motor windings, and motor torque proportional to motor currents is adjusted by controlling current value of said variable constant current source. Further, a supply voltage control loop is provided, so that power loss at the variable constant current source becomes minimum.
Claims11
A dc motor drive circuit for controlling torque of a dc motor comprising:
- a power supply terminal;
- a reference voltage terminal;
- a plurality of switching circuits,
- a plurality of windings for said motor interconnected by said switching circuits between said power supply terminal and said reference voltage terminal for supplying driving power to said windings;
- and
- a variable constant current circuit connected in circuit with said motor windings and said first power supply terminal and said reference voltage terminal and said variable constant current circuit controlling the torque of said dc motor in response to a control signal supplied to said variable constant current circuit.
A torque control circuit for a brushless dc motor driving circuit comprising, a power supply terminal, a control signal terminal, a plurality of series circuits each of which includes a first transistor, first and second diodes and a second transistor serially connected between said power supply terminal and a variable constant current circuit, a dc motor having a plurality of stator windings, each of said stator windings being respectively connected to the connection point of said first connected diodes of said series circuits, a constant current circuit controlled in its current value by a control signal fed from said control signal terminal.
A torque control circuit for a brushless dc motor driving circuit comprising, a power supply terminal, a control signal terminal, a plurality of series circuits each of which includes a first transistor, first and second diodes and a second transistor serially connected between said power supply terminal and a variable constant current circuit, a dc motor having three stator windings, each of said stator windings being respectively connected to the connection point of said first connected diodes of said series circuits, a constant current circuit controlled in its current value by a control signal fed from said control signal terminal.
Dependencies are inferred from the claim text.