Negative and positive switching ignition signal conditioner
US4112350A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1977 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Sep 15, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02P17/10
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The signal indicative of switching of the ignition primary coil of a spark ignition engine is conditioned by means of compatible, combined, multiple and variable threshold testing of both the high end and the low end of the coil primary, without need to know (or alter operation in dependence upon) whether the engine employs positive switching at the high end of the primary coil or negative switching at the low end of the primary coil. To sense the end of the dwell period, the high coil voltage is compared against a negative voltage which will never occur if low coil switching is employed, but which will occur at the start of firing time in a positive switching system. Similarly, low coil is compared against a positive voltage which would never occur in a positively switched system, but which does occur at the start of firing time if negative switching is used. The circuits recognizing the start of dwell time require both that high coil be in excess of some low voltage and that low coil be less than some fraction of battery voltage; when positive switching is used, low coil is always at or near ground and therefore always meets the test; when negative switching is used, high coil is…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.