Variable speed D.C. motor control
US5003628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1989 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Mar 2, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/91
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A manually operated switch lever moves arm 105 along resistor 113 to generate a "raw" motor speed demand signal which is amplified and inverted by amplifiers 115 and 119 to form a "base line" demand signal. The "raw" demand signal and a motor load signal at the output of amplifier 154 are compared in amplifier 125 to generate an "error" signal. The "error" signal and the "base line" demand signal are summed in amplifier 129 to form a variable reference voltage which is applied to the non-inverting input of comparator 132. The second input to comparator 132 is a triangular shaped wave which is centered about V/2. When the amplitude of the oscillator output wave exceeds the reference voltage, the output of the comparator 132 is low and switch 160 is off. Thus, variations in the D.C. reference voltage at the output of amplifier 129 control the ON-off duty cycle of MOSFET switch 160 to adjust the power applied to motor 106.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.