Abstract: A brush assembly having a brush wear indicator for use with electric actuating devices such as motors and generators that detects the worn condition of a brush and generates a signal indicating this worn condition.

Abstract: A brush assembly having a brush wear indicator for use with electric actuating devices such as motors and generators that detects the worn condition of a brush and generates a signal indicating this worn condition.

Abstract: A power maximizing circuit for a stepper motor employing a switching regulator that conducts current to a variable voltage supply until a predetermined voltage is attained. The predetermined voltage is varied to achieve resonance compensation.

Abstract: A variable speed control for an encoderless, brushless, direct current motor. An input signal, representing a desired speed of the motor, is received by both a variable power supply and a counter. The counter responsively issues a sequence of signals corresponding to particular motor windings to be energized. The variable power supply issues a motor supply voltage in accordance with the input signal as well. An error corrector circuit is connected to both the counter and the windings of the motor. The corrector circuit senses a voltage waveform on a winding when the counter signal indicates that the winding is not energized. If the winding voltage waveform deviates from a predetermined standard, the corrector circuit gives a correction command to the variable power supply. The variable power supply accordingly increases or decreases the motor supply voltage.

Abstract: A closed loop resonance compensation method and circuit for a stepper motor stabilizes the stepper motor control system while operating in the mid-frequency range. The stepper motor stabilization method and means corrects for mid-frequency resonance errors by deriving a velocity error signal from the total current in the motor windings and uses this signal, through feedback to the source of clock pulses, to correct the short term rotor velocity with respect to the stator field.

Abstract: An input control circuit for a step motor is disclosed. The circuit includes three separate counters for selectively monitoring command pulses and motor pulses such that the rate of acceleration and the initial point of deceleration are independent of (i) the entry rate of command pulses and (ii) the entry timing. This permits operation of the step motor with an undedicated source of command pulses, e.g., a microprocessor.

Abstract: An accommodation circuit for converting the energization pattern provided to a step motor by a logic sequencer is disclosed herein. The circuit provides a series of override signals in response to the clock controlling the logic sequencer. The override signals are combined with the energization signals provided by the logic sequencer to convert the energization pattern to a predetermined alternate pattern.

Abstract: A deceleration initiation circuit for a stepper is described, wherein a monitor signal representing each drive pulse received by the stator and a deceleration signal representing a predetermined drive pulse are compared. A deceleration initiating signal is issued whenever a predetermined relationship exists between the signals.

Abstract: An acceleration shaping circuit for a stepper motor is described and includes two voltage storage devices. One is charged linearly and the other is charged exponentially. The output ramp voltage is an adjustable combination of the two stored voltages and is therefore variable between a linear ramp voltage and an exponential ramp voltage.