Low loss snubber circuit
AssigneeGeneral Electric Company
InventorWilliam R. Archer
Life of this patent
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Abstract
An improved snubber circuit for a bipolar switching transistor connected to drive an inductive transformer load comprises a first resonant circuit connected to the driven winding of the transformer and a second resonant circuit connected to a clamp winding of the transformer. At turn-off, the two resonant circuits provde an alternate current path for inductive currents to thereby limit the voltage applied to the load transistor. The circuit are interconnected to minimize component count in a manner which permits resetting the capacitive components to improve snubbing capability.
Claims3
A voltage snubber circuit for limiting voltage overshoot during turn-off in a relatively high-frequency power switching circuit of the type including a controllable switching element connected in series with a primary winding of a power transformer across a source of DC voltage, a clamp winding coupled to the primary winding and connected via a clamping diode across the DC source for limiting the voltage applied to the switching element during turn-off and a first capacitor-diode circuit connected across the primary winding for dissipating the energy in the primary winding leakage flux during turn-off, the improvement comprising;
- a second capacitor-diode circuit connected across the clamp winding for establishing current flow in the clamp winding at a voltage less than the source voltage;
- and
- means for interconnecting said first and said second capacitor-diode circuits whereby turn-on of the switching element creates a current path through at least the capacitor portions of said first and said second capacitor-diode circuits in a direction to discharge the capacitor portions of said capacitor-diode circuits preparatory to turn-off of the switching element.
Dependencies are inferred from the claim text.