Pulse motor control device
AssigneeZexel Corporation
InventorHiroshi Ohsawa
Life of this patent
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Abstract
A pulse motor control device comprises, as additional component parts, a power-off detecting circuit, and a turning-off circuit. The power-off detecting circuit detects, when a driving switch is turned off, a dropping of a voltage supplied to a driving circuit and outputs a power-off detection signal. The turning-off circuit includes diodes and a control resistor. The diodes are connected respectively to control terminals of all driving transistors of the driving circuit. When the control transistor is turned on in response to the power-off detection signal, voltages of control terminals of the driving transistors are dropped to the ground level through the diodes, thereby turning off the driving transistors.
Claims4
A pulse motor control device comprising:
- (a) a driving circuit connected to a power supply line extending from a power source and having a plurality of switching elements for controlling the supply of electric current to a plurality of driving coils of a pulse motor;
- (b) a power source circuit connected to said power supply line and adapted to generate a constant voltage;
- (c) a control circuit which is activated upon receipt of the constant voltage from said power source circuit, said control circuit sending control signals respectively to said switching elements so that said switching elements are turned on, thereby energizing said driving coil in accordance with a predetermined sequential order;
- (d) a driving switch disposed on said power supply line, said driving circuit and said power source circuit being connected to said power source through said driving switch;
- (e) power-off detection means for detecting that voltage supplied to said driving circuit is lowered when said driving switch is turned off and outputting a power-off detection signal;
- and
- (f) turning-off means for forcibly turning off all said switching elements of said driving circuit in response to the power-off detection signal.
Dependencies are inferred from the claim text.