Over-dwell protection circuit for an automotive ignition control system
US7013882B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2003 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Aug 26, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2041/2075
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An ignition control circuit (12) is responsive to a control signal (ESTC) to apply a drive signal (GD) to a power switching device (22) to conduct ignition coil current (IC) therethrough. A resistor (RS) included within the circuit (12) receives, and dissipates heat generated by, the coil current (IC). The circuit (12) includes a first transistor (QHOT) positioned adjacent to the resistor (RS) such that an operating temperature thereof is near that of the resistor (RS), and a second transistor (QREF) positioned remote from the resistor (RS) and having an operating temperature defining a reference temperature. The first and second transistors (QHOT, QREF) are configured to produce an output voltage (VOUT) proportional to a difference in operating temperatures thereof, and a latch circuit (L1) disables the control signal (ESTC) to thereby turn off the power switching device (22) when the output voltage (VOUT) difference exceeds a reference voltage (VREF).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.