Browse Prior Art Database

Motor Control System

IP.com Disclosure Number: IPCOM000093541D
Original Publication Date: 1967-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Boggs, B: AUTHOR [+3]

Abstract

The motor circuit in drawing A compares speed-indicative pulses from a tachometer with reference pulses from a single-shot. A capacitor is charged and discharged under control of the differences resulting from the comparison to increase or decrease the speed of the motor.

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Motor Control System

The motor circuit in drawing A compares speed-indicative pulses from a tachometer with reference pulses from a single-shot. A capacitor is charged and discharged under control of the differences resulting from the comparison to increase or decrease the speed of the motor.

The circuit includes motor 1 driving tachometer 2, single-shot 3, inverters 4 and 5, transistors T1...T5 and capacitor C. The circuit action is shown in the waveforms at B. The speed of motor 1 is reflected, by pulses A and A through a shaper circuit that includes transistor T5 and inverter 4.

Longer A and A pulses indicate motor speed too low and shorter A and A indicate motor speed too high. Single-shot 3 produces reference pulses B and B in connection with inverter 5. Tachometer 2 pulses and reference pulses are applied to input circuits associated with T1 and T2 for controlling the charge and discharge rate of C and, ultimately, to change the current through T3 and T4, thus regulating the speed of motor 1.

The waveform conditions in drawing B during time interval t1 exist when motor speed is low and those shown during time interval t2 exist when motor speed is too high. When tachometer A pulses are longer than single-shot B pulses, T1 is switched on for interval t1. This increases voltage V1 which decreases voltage V2 to speed up motor 1. When motor speed is high, single- shot B pulses are longer than tachometer A pulses, switching T2 on during interval t2, V1 decreases,...