Electric motor with integral regulator inductance
An apparatus and a method of manufacture of a DC electric motor operable over a range of voltage by virtue of a DC-DC regulator having an inductance provided by one or more windings on the stator of the motor. A conductor is wound about an interpole of the stator and coupled, as an inductance, to a voltage regulator circuit, allowing operation of the DC motor over a substantial range of input voltage.
1. In a voltage regulator circuit for governing a voltage applied to field windings of a DC motor having a stator yoke and characterized in operation by a commutation frequency, the improvement comprising:
a winding of conductor about an interpole of the stator yoke, the winding characterized by an inductance electrically coupled to the voltage regulator circuit, wherein the voltage regulator circuit is a buck regulator designed for operation at a pulse frequency that is higher than the motor commutation frequency.
2. A motor capable of operation over a substantial range of input voltage, the motor characterized in operation by a commutation frequency, the motor comprising:
a stator characterized by pole sections and interpole sections;
a coil of conductive wire wound about at least one of the interpole sections; and
a regulator circuit incorporating the coil of conductive winding as an inductive circuit element; wherein the regulator circuit is a buck regulator designed for operation at a pulse frequency that is higher than the motor commutation frequency.
3. A method for regulating a voltage applied across a field winding of a DC motor, the method comprising:
converting the applied voltage to periodic pulses; and
smoothing the periodic pulses in a circuit including an inductor wound about a stator interpole of the DC motor.
4. A method in accordance with claim 3 , wherein the step of converting the applied voltage to periodic pulses is done by a controller providing a periodic switching voltage to a pass switch.
5. A method in accordance with claim 4 , wherein the pass switch is a transistor.
6. A method in accordance with claim 4 , wherein the controller is an integrated circuit.
7. A motor capable of operation over a substantial range of input voltage, the motor characterized in operation by a commutation frequency, the motor comprising:
a stator characterized by pole sections and interpole sections;
a coil of conductive wire wound about at least one of the interpole sections; and
a regulator circuit incorporating the coil of conductive winding as an inductive circuit element;
a rotor section having rotating magnets, wherein the rotating magnets of the rotor section induce a secondary voltage into the inductive circuit element;
wherein the steps of converting the applied voltage to periodic pulses and smoothing the periodic pulses are performed by means of a buck regulator.