Pulse width modulated solenoid driver controller
US5621603A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Jul 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/0822
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electronic drive circuitry for a solenoid that utilizes a pulse width modulation scheme is disclosed. The solenoid is connected in series with a transistor and a sense resistor. The voltage across the sense resistor is compared to a reference value to determine if an over-current condition exists within the solenoid. The circuitry operates on a repetitive time window scheme in which current is allowed to flow through the solenoid at the beginning of each time window, regardless of whether an over-current condition exists. If an over-current condition was detected at any time during the time window, then the current will be shut off to the solenoid during the next time window after the initial portion of that window. Conversely, if no over-current condition was detected during a time window, current will be allowed to flow during the entire duration of the next time window. Wraparound circuitry is also provided for sensing an open-coil condition during a latter portion of one of the time windows after a plurality of such windows has elapsed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.