Apparatus for sensing the presence of an inductive load driven by a pulse width modulated signal
US6873190B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2003 |
| Grant date | Mar 29, 2005 |
| Priority date | — |
| Expiry date | Mar 18, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/325
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for sensing the presence of an inductive load that is particularly applicable to sensing when a solenoid is being driven by a pulse width modulation (PWM) signal. The circuit includes a high side connected transistor having an output driving a load, with the transistor driven by a PWM signal. A circulating diode is coupled to the driving output of the transistor. The circuit further comprises an operational amplifier (op amp) circuit that is coupled to the circulating diode and operates as an inverting operational amplifier (op amp). The op amp circuit charges a first capacitor when the transistor releases driving an inductive load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.