Smart fuel pump controller
US5055758A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1990 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Mar 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D16/2066
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The motor drive circuit has an instrumentation amplifier with a programmable gain set by selectively blowing fuses during initial circuit calibration. The quasi-sawtooth waveform of a relaxation oscillator is compared with the amplified and conditioned signal produced by a pressure responsive Wheatstone bridge circuit. The result of this comparison is a drive signal which controls the pump motor speed. Radio frequency interference is minimized by storing the motor drive current in a capacitor located near the motor. Further interference is minimized by a reactive matching circuit which combines with the motor impedance to result in a purely resistive load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.