Ignition system dwell control
US4836175A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1988 |
| Grant date | Jun 6, 1989 |
| Priority date | — |
| Expiry date | Aug 1, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02P3/0456
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A control circuit for developing a digital signal for use in a closed loop dwell control of an electronic internal combustion engine ignition system. The circuit has a ramp counter and a down-counter. The ramp counter counts-up clock pulses for a period of time beginning when the primary winding of an ignition coil is energized and ending when primary winding current increases to a sensed current limit value. When current limit is reached, the most significant bits of the count in the ramp counter are loaded into the down-counter. The ramp counter is now counted-up and the down-counter is counted-down until the down-counter underflows. The final or ultimate count magnitude in the ramp counter is equal to the count attained by the ramp counter between energization of the primary winding and attainment of current limit added to a fixed percentage of the count attained by the ramp counter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.