Open loop computer-controlled spark ignition timing system
US4273089A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 12, 1979 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Sep 12, 1999 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02P3/0456
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An electronic system for controlling the firing time of a spark ignition, internal combustion engine counts teeth or other code indicia as an angle-related, closed-loop, coarse indication of firing angle and follows the coarse indicating count with a fine, variable open-ended time delay in response to clock signals currently related to engine angle, to provide firing angles which fall within a tooth (or other indicium). In one embodiment, a pre-dwell period of fixed angular extent, determined by a fixed tooth count, is followed by a variable dwell period including a variable tooth count portion, a fixed speed measurement and calculation time portion, and a variable, final clock time-out portion. In the disclosed embodiment, the system is controlled and calculations are performed by a microprocessor, whereas tooth counting, tooth-to-tooth clock calibration and clock counting are performed by a hardware counter which is controlled by hardware logic circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.