Single-ended self-oscillating dc-dc converter for intermittently energized load having V.sub.BE responsive current limit circuit
US4800323A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1987 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Jul 17, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The converter delivers current to an intermittently energized load and includes a coupled inductor having a primary winding, a secondary winding and a feedback winding. A switching transistor is coupled in series with the primary winding of the inductor and switches between conductive and non-conductive states to control the flow of current through the primary winding. A positive drive circuit provides positive bias voltage to the switching transistor. A current limiting circuit senses the voltage across the base-emitter junction of the switching transistor to measure the primary winding current, removes the positive bias voltage when the primary winding current reaches a predetermined value, and thereby switches the transistor out of the conductive state into the non-conductive state. A semiconductor switch includes a control lead coupled to a voltage divider which applies a scaled voltage to the control lead causing the semiconductor switch to conduct when the switching transistor base-emitter voltage reaches a predetermined current limit voltage representative of a preselected switching transistor collector current limit. The semiconductor switch then shunts the positive bias vo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.