Method of operating a PWM solenoid valve
US4766921A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 17, 1986 |
| Grant date | Aug 30, 1988 |
| Priority date | — |
| Expiry date | Oct 17, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86622
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention provides an improved method of operating a pulse-width-modulated solenoid valve so as to improve the proportionality of the flow-to-command pulse width characteristics of the valve. A train of command pulses (P.sub.1, P.sub.2, . . . P.sub.n), having widths corresponding to the desired flow through the valve, is superimposed on another train of pre-pulses (p.sub.1, p.sub.2, . . . p.sub.n). Each pre-pulse is timed to appear immediately ahead of an associated command pulse so that their widths will be effectively summed. The pre-pulses have widths necessary to substantially eliminate the "deadzone" in the flow-to-pulse width characteristics of the valve. Hence, the proportionality of the flow-to-command pulse width characteristics of the valve will be substantially improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.