Back to results
US 4,054,819 AGranted
Motor angular velocity monitor circuit
AssigneeSperry Rand Corporation
InventorRichard Severn Johnson
Life of this patent
Estimating the term…
Abstract
A circuit for controlling the operation of a bi-directional motor. A motor energized to run in one direction is stopped by applying a reverse or braking current to its energizing field. When the motor is virtually stopped, means are provided to de-energize the motor to prevent the motor from reversing direction.
Claims12
A circuit for controlling the operation of a bi-directional motor having an excitation winding, comprising in combination;
- a motor drive circuit electrically connected to the motor,
- said motor drive circuit having first and second input terminals and including logic circuit means for energizing the motor in a first rotational direction only when said first and second input terminals have coincident highs and in a second rotational direction only when said first input terminal has a high coincident with a low on said second input terminal,
- control means connected to said first terminal for removing the high therefrom to de-energize the motor when its speed reaches a predetermined amount.
A motor velocity sensor for providing an output pulse when the speed of a motor reaches a predetermined level, comprising in combination,
- a tachometer generator connected to the output shaft of the motor and providing output pulses whose length of duration are indicative of motor speed,
- a gate providing an output pulse in response to two coincident input pulses,
- first means connecting the output of said tachometer as one input to said gate,
- a voltage comparator having a reference voltage input terminal and a variable voltage input terminal providing a low as an output when the voltage on the variable voltage input terminal exceeds the voltage on said reference voltage input terminal,
- second means connecting the output of said voltage comparator as the second input to said gate, and
- circuit means connected between said tachometer generator and said variable voltage input terminal of said voltage comparator for providing an output whose amplitude is proportional to the speed of the motor whereby said gate provides an output whenever the speed of the motor reaches the predetermined level, said circuit means comprising
- a capacitor having one side connected to ground,
- a DC power supply,
- a resistance connected between said power supply and the other side of said capacitor, and
- second means connecting the output of said tachometer generator to the junction of said resistance and said capacitor, said junction being connected to said variable voltage input terminal of said voltage comparator.
7 more elements
Dependencies are inferred from the claim text.