Self-snubbing bipolar/field effect (biofet) switching circuits and method
Resonant-transition DC-to-DC converter Patent #: 5132889
ApplicationNo. 910790 filed on 07/08/1992
US Classes:363/21.02, For resonant-type converter363/56.11, Having voltage protection363/56.12Transient protection (e.g., snubber, etc.)
ExaminersPrimary: Stephan, Steven L.
Assistant: Berhane, Adolf
Attorney, Agent or Firm
Foreign Patent References
International ClassH02H 007/122
Foreign Application Priority Data1991-07-12 JP
AbstractA voltage-resonant DC-DC forward converter is provided with a snubber circuit in its secondary circuit. The snubber circuit comprises a series connection of a first capacitor and a first diode connected to both ends of the secondary winding of the main transformer to make up a loop of a secondary resonance circuit which allows a secondary resonance current to flow in the forward direction of the first diode, the forward direction being so directed that the first diode blocks the secondary resonance current from flowing at least while the second winding supplies a current to the smoothing circuit through a second diode for rectifying the secondary current. The converter is further provided with a regulation circuit for regulating the output voltage of the converter. The circuit has a transistor for controlling switching of the output current which varies linearly with time. The transistor is controlled by the sum of the voltage signal indicative of the output current and of the deviation signal indicative of the deviation of the output voltage from a prescribed value. When the sum exceeds the base-emitter threshold voltage, the transistor is turned on to switch off the output current.