Solenoid driver control circuit with initial boost voltage
US4729056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1986 |
| Grant date | Mar 1, 1988 |
| Priority date | — |
| Expiry date | Oct 2, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/1844
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An improved solenoid driver control circuit is disclosed in which solenoid current is sensed and provided as an input to a comparator means comprising two separate comparators (24, 25). The comparator means receives a solenoid current sense signal (45) and maximum and minimum reference threshold levels which determine maximum and minimum current limits (I.sub.max, I.sub.min ; H.sub.max, H.sub.min) for solenoid current during initial pull-in excitation and subsequent hold excitation. Pull-in time (T.sub.1) is defined by a monostable multivibrator (33) reacting to a control pulse (41) to produce a predetermined pull-in time pulse (43) such that the pull-in time is independent of sensed solenoid current. During pull-in time a boost driver switch (53) applies high boost voltage to a power source terminal (16) which supplies solenoid current, and in response to achieving the maximum pull-in current limit (I.sub.max) lower battery voltage is provided at the power source terminal. If the maximum pull-in current limit does not occur within a predetermined time (t.sub.b1) after pull-in initiation (at t.sub.0), then the lower battery voltage is applied to the power source terminal at that ti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.