Current limited constant frequency dc converter
US4686617A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 1986 |
| Grant date | Aug 11, 1987 |
| Priority date | — |
| Expiry date | Jun 6, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A constant-current, current-programmed dc-to-dc converter includes a controllable switch and an inductor. The switch is rendered conductive in response to a recurrent clock signal, and nonconductive in response to a comparison of a voltage representing the inductor ramp current with an output voltage error signal from a high impedance source, which establishes an output voltage control feedback loop. An overcurrent limiting circuit includes a current sensor having a low output impedance which produces a load current representative signal. The load current representative signal is applied to an amplifier having a low output impedance and which includes a diode in its feedback loop to maintain it nonsaturated. A second diode is connected to the output of the amplifier and to the high impedance output terminal of the error voltage source to close a current limiting degenerative feedback loop which swamps the error voltage when the second diode becomes conductive due to excess load current. This reduces the peak value of inductor current sufficient to maintain the desired load current limit. If the amplifier fails open-circuit, both diodes conduct to the low impedance current sensor an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.