Governor circuit for universal series (or compound) motor
OwnerTai-Her Yanginventor
Life of this patent
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Abstract
A governor circuit for limiting the top speed of a universal series or compound motor. The governor circuit includes a voltage detector for detecting a selectable threshold voltage across the armature of the motor, and a current shunting circuit which is triggered by the voltage detector when the armature voltage of the motor reaches the threshold level to thereby shunt current through an auxiliary field winding and around the armature and/or main field winding, thereby limiting the speed of the motor. A plurality of embodiments is disclosed which accommodate various conventional power supply types.
Claims28
A governor circuit for limiting the top speed of a universal series motor of the type having a series-connected main field winding and armature winding, said governor circuit comprising:
- a voltage detector circuit coupled to the armature of said motor for detecting a threshold voltage across said armature;
- an auxiliary field winding;
- and
- a current shunting circuit connected in series with said auxiliary field winding, said series connected auxiliary field winding and shunting circuit being coupled across said armature for providing a current shunt path around said armature, said current shunting circuit also being connected to said voltage detector circuit and triggered thereby upon detection of said threshold voltage to shunt current through said auxiliary field winding;
- whereby said armature voltage is clamped at a constant level and the motor is limited to a maximum speed in accordance therewith.
A governor circuit for limiting the top speed of a universal series motor of the type having a series-connected main field winding and an armature winding, said governor circuit comprising:
- a voltage detector circuit coupled to the armature of said motor for detecting a reference voltage across said armature, said voltage detector circuit further comprising,
- four diodes including a first diode through a fourth diode connected in a full bridge configuration, and
- a series connected first resistor and second resistor coupled across said diode bridge for providing a reference voltage at the junction between said first resistor and second resistor;
- a current shunting circuit connected across said diode bridge for selectively shunting current therethrough and around said armature, said current shunting circuit further comprising,
- a silicon controlled rectifier having anode, cathode and gate electrodes;
- an auxiliary field winding;
- said silicon controlled rectifier anode and cathode being connected in series with said auxiliary field winding across said diode bridge, and
- a diode connecting said gate of said silicon controlled rectifier to the junction between said first resistor and second resistor, said silicon controlled rectifier being triggered by said reference voltage to shunt current through said auxiliary field winding;
- whereby the voltage across said armature is clamped at a constant level and the motor is limited to a maximum speed in accordance therewith.
A governor circuit for limiting the top speed of a universal series motor of the type having a series-connected main field winding and an armature winding, said governor circuit comprising:
- a voltage detector circuit coupled to the armature of said motor for detecting a reference voltage across said armature, said voltage detector circuit further comprising,
- four diodes including a first diode through a fourth diode connected in a full bridge configuration, and
- a series connected resistor and capacitor coupled across said diode bridge for providing a reference voltage at the junction between said resistor and capacitor;
- a current shunting circuit connected across said diode bridge for selectively shunting current therethrough and around said armature, said current shunting circuit further comprising,
- a silicon controlled rectifier having anode, cathode and gate electrodes;
- an auxiliary field winding;
- said silicon controlled rectifier anode and cathode being connected in series with said auxiliary field winding across said diode bridge, and
- a diac connecting said gate of said silicon controlled rectifier to the junction between said resistor and capacitor, said silicon controlled rectifier being triggered by said reference voltage to shunt current through said auxiliary field winding;
- whereby the voltage across said armature is clamped at a constant level and the motor is limited to a maximum speed in accordance therewith.
A governor circuit for limiting the top speed of a universal series motor of the type having a series-connected main field winding and an armature winding, said governor circuit comprising:
- a voltage detector circuit coupled to the armature of said motor for detecting a reference voltage across said armature, said voltage detector circuit further comprising,
- four diodes including a first diode through a fourth diode connected in a full bridge configuration, and
- a series connected first resistor and second resistor coupled across said diode bridge for providing a reference voltage at the junction between said first resistor and second resistor;
- a current shunting circuit connected across said diode bridge for selectively shunting current therethrough and around said armature, said current shunting circuit further comprising,
- an auxiliary field winding;
- a transistor having a collector and emitter connected in series with said auxiliary field winding said series-connected transistor and auxiliary field winding being connected across said diode bridge, said transistor additionally having a base connected to the junction between said first resistor and second resistor, said transistor being triggered by said reference voltage to shunt current through said auxiliary field winding;
- whereby the voltage across said armature is clamped at a constant level and the motor is limited to a maximum speed in accordance therewith.
A governor circuit for limiting the top speed of a universal series motor of the type having a series-connected main field winding and armature winding, said governor circuit comprising:
- a voltage detector circuit coupled to the armature of said motor for detecting a threshold voltage across said armature;
- an auxiliary field winding;
- and
- a current shunting circuit connected in series with said auxiliary field winding, said series connected auxiliary field winding and shunting circuit being coupled across said armature for providing a current shunt path around said armature;
- an isolator circuit connected between said current shunting circuit and said voltage detector for providing an electrically isolated coupling therebetween, said current shunting circuit being triggered by said voltage detector via said isolator circuit upon detection of said threshold voltage to shunt current through said auxiliary field winding;
- whereby said armature voltage is clamped at a constant level and the motor is limited to a maximum speed in accordance therewith.
Dependencies are inferred from the claim text.