Device to provide a regulated power supply for in-cylinder ionization detection by using a charge pump
US6922057B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2003 |
| Grant date | Jul 26, 2005 |
| Priority date | — |
| Expiry date | Jul 4, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A charge pump is used to supply current to the ionization detection circuit. To detect in-cylinder ions generated during the combustion process, a DC bias voltage needs to be applied. There are two ways to generate the DC bias: conventional DC power supply (large electronics) and capacitor charges by primary or secondary flyback voltage (high voltage capacitor). Typically, flyback voltage is used to charge the capacitor which supplies current to the ionization detection circuit. This necessitates the use of high voltage capacitors. Generally, ceramic capacitors are used. However, as temperature fluctuates, the board that the capacitor is mounted on can flex, causing the ceramic capacitor to crack. This invention proposes to use a high voltage charge pump to provide enough DC bias voltage for measuring ionization current. In a preferred embodiment, a model number M1C4827 EL driver is used in the charge pump circuit. The charge pump circuit will convert the 12 Volt DC at the B+ terminal to a 90 to 100 volt pulse train with a pulse repetition frequency of 500 kHz at the charge pump output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.