Overcurrent protecting device for use in DC--DC converter
US5724235A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 26, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | Dec 26, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a DC-DC converter, and aims at preventing a flywheel switch from being destroyed. A PWM control circuit outputs an oscillation signal in order to alternately switch between a main switch and a rectification switch, and a flywheel switch. A state detecting unit generates a control instruction signal for a controlling unit, if the DC-DC converter is powered down or if it is overloaded. The controlling unit turns off the flywheel switch by controlling a driving circuit which controls the on/off status of the flywheel switch. An electric current I.sub.Q2 flows via a parasitic diode D.sub.Q2, when the flywheel switch is turned off. With the above described configuration, the flywheel switch can be prevented from being destroyed, when the DC-DC converter is overloaded, or when an overcurrent occurs due to power-down.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.