Current regulation circuit for inductive loads
US5057765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1991 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | Feb 5, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/1563
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An integrated circuit voltage chop circuit for regulating the current in an inductive load is of the type having a fixed off time. A current-sensing comparator produces a reset signal when the current through the driver exceeds a predetermined peak amplitude. A load driver transistor is turned on and off according to the state of a bistable memory elememt, e.g. a flip flop. An external capacitor and external series resistor are connected to the integrated circuit and they determine the driver off time. A voltage comparator having hysteresis produces a high output logic level when the capacitor charges to a predetermined voltage which sets the flip flop and begins to slowly discharge the capacitor. When the capacitor discharges to a lower predetermined voltage, the voltage comparator output goes to a low logic level turning on a shorting transistor that quickly discharges the capacitor completely. A logic gate with an output connected to the reset terminal of the flip flop resets the flip flop when both the output of the voltage comparator is in the low level and the output of the current-sensing comparator produces the reset signal. Thus during the period in which the capacitor is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.