Back to results
US 4,306,281 AGranted
DC-DC Converter for electronic flash unit
AssigneeCanon Kabushiki Kaisha
InventorTadashi Okino
Life of this patent
Estimating the term…
Abstract
In a DC-DC converter for an electronic flash unit disclosed, an npn transistor is used as an oscillating transistor. The emitter of the npn transistor is connected to a main capacitor of the flash unit at least through a secondary winding of the converter. A diode is connected between the secondary winding and the main capacitor in such a manner that the emitter current of the npn transistor can flow into the main capacitor as an charging current through the secondary winding.
Claims7
A DC-DC converter for an electronic flash unit having a main capacitor, said DC-DC converter comprising:
- (a) an oscillating transformer having a primary winding, a secondary winding and a feedback winding;
- (b) an npn oscillating transistor having an emitter connected to one electrode of said main capacitor through the secondary winding of said transformer, said transistor being arranged to apply a current for charging the main capacitor therewith;
- and
- (c) rectifying means which is arranged in a forward direction for said charging current and is connected between said one electrode of the main capacitor and the secondary winding of said transformer.
1 more element
Dependencies are inferred from the claim text.