Curtis Instruments Inc.

Opalec

William M. Brobeck & Associates

Stephen F Post

Scott A Bowman

Steven J Lacker

Andrew J Shepherd

Roger White

Marc R Davis

George L Ackerson

Warren J Vinzant

Donald L Pellow

David Mele

Circuits, systems, and methods are disclosed to eliminate the requirement for an external electromechanical contactor. Integrating contactor circuits with a motor controller reduces cost. Additionally, the cost of the contactor circuit may be reduced by providing transistors designed to block current in only one direction in the event of an electrical fault corresponding to an electrical drive direction.

Motor controller with integrated safety function to eliminate requirement for external contactor

Electric motor controllers that dynamically adjust a motor resistance parameter are described. In order to adjust the motor resistance parameter, power is applied the electric motor while the controlled vehicle is stopped and its brake is set so that the vehicle remains stopped while a measurement is taken that can be used to determine motor resistance. A new motor resistance value is then generated based at least in part upon the measurement(s) and the motor resistance parameter is set to the new motor resistance value. The new motor resistance parameter may then be used in the control of the electric motor. In some embodiments, the measurements are taken after the controller receives a brake release request but before actually releasing the brake. The described arrangement can be used in a wide variety of motor controllers and is especially well suited for use in low cost controllers that control motors that are susceptible to wide variations in their resistance such as brushed permanent magnet DC motors.

Systems and methods for dynamically compensating motor resistance in electric motors

An LED illumination module for a flashlight has a housing, electronic control circuitry, and one or more LEDs connected in series and to the circuitry. The module is characterized in that the module is shaped to modularly replace an incandescent-bulb in an existing flashlight. In one aspect the control circuitry operates in a dual mode to extend life of the unit, and to warn when battery replacement is warranted.

Dual mode regulated light-emitting diode module for flashlights

In a preferred embodiment, an engine oil change indicator system, including: a combination engine oil pressure sensor and engine oil temperature sensor connected to a port on the engine to which port is normally connected an oil pressure switch; and a microprocessor connected to receive inputs from the combination engine oil pressure sensor and engine oil temperature sensor and to cause a low engine oil pressure warning light to be illuminated when the microprocessor has calculated from the inputs that the engine oil should be changed.

Engine oil change indicator system

Heatsink enclosure for an electrical controller

A motor controller comprises a plug detect circuit which detects 'continuous' plug diode conduction during plug braking. The plug detect circuit detects 'continuous' plug braking by detecting when a plug diode is or is not conducting current throughout substantially the entire time that a power MOSFET controlling the plug braking is conductive in one pulse width modulated MOSFET switching cycle. Continuous plug detection facilitates the motor controller's controlling a vehicle so that the vehicle has a more constant and smooth plug braking deceleration and subsequent powered acceleration in the opposite direction. According to another aspect of the invention, a motor controller comprises a POT HI and a POT LO driver circuit. The POT HI and POT LO driver circuits allow the detection of faults in throttle devices and the connections of the throttle devices to the POT HI and POT LO driver circuits. One of the POT HI and POT LO driver circuits has a greater current limit than does the other driver circuit so that numerous faults including open circuit breaks in the connection of a throttle device as well as shorts across or through the throttle device are detectable by the motor controller.

Electric motor controller

In a preferred embodiment, a high-frequency, pulse-width-modulated, power-transistor, DC motor speed controller having current limiting in both drive and regenerative modes, essentially constant ramping rates regardless of whether or not the operator switches to neutral before changing direction, a simple sequencer which controls the timing of four functions--both drive and regenerative current measuring circuits and both drive and regenerative transistors, a highly effective transistor filter capacitor arrangement, and circuitry in which the level of regenerative current is used as an input to control the current under which the direction relays switch.

Method and apparatus for DC motor speed control

The system includes a plurality of parallel-connected power field effect transistors arranged for connection in series with the traction motor with a common control circuit connected to the gate electrodes of the field effect transistors to control the on-off cycle of conduction through the field effect transistors. A plurality of parallel connected power diodes are arranged for reverse connection in parallel with the traction motor to serve as freewheeling diodes. The diodes are physically positioned apart from one another and distributed in position among the field effect transistors and each diode is positioned in a similar manner with a group of associated field effect transistors for ease of transfer of current flow between the diode and the associated field effect transistors.

Solid state d.c. motor control

An electronic controller for DC motors is provided which is particularly adapted for use on electric vehicles. The controller is of the pulse-width type wherein a chopper is employed to divide the current into a series of pulses and the output of the controller is regulated by the width of the pulses. A number of protective devices are built into the circuit, including an active current limiter, a main current limiter and a back-up limiter whereby it is virtually impossible to damage the individual components.

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Walnut Creek, CA, United States of America

Stephen F Post