초록 ▼

A drive circuit for a voltage controlled power switching device includes a transformer, a full-wave rectifier bridge coupled to the transformer, first and second capacitors connected in series between nodes of the full-wave rectifier bridge and first and second controlled switches coupled between a

A drive circuit for a voltage controlled power switching device includes a transformer, a full-wave rectifier bridge coupled to the transformer, first and second capacitors connected in series between nodes of the full-wave rectifier bridge and first and second controlled switches coupled between a control electrode of the power switching device and the first and second capacitors, respectively, wherein each controlled switch has a control electrode coupled to a secondary winding of the trans-former. Current is provided by the first capacitor to the control electrode of the power switching device through the first controlled switch at the beginning of a negative pulse appearing at the secondary winding of the transformer and charging current is provided to the first capacitor from the secondary winding of the transformer through the full-wave rectifier bridge after the beginning of the negative secondary pulse. Current is drawn from the control electrode of the power switching device through the second controlled switch to the second capacitor at the beginning of a positive pulse appearing across the secondary winding and charging current is provided to the second capacitor from the secondary winding of the transformer through the full-wave rectifier bridge after the beginning of the positive pulse.

대표청구항 ▼

[ I claim:] [1.] A drive circuit for a power switching device, comprising:a transformer having a primary winding and a secondary winding across which secondary pulses of first and second polarities and first and second magnitudes are developed when input pulses of opposing polarities are provided to

[ I claim:] [1.] A drive circuit for a power switching device, comprising:a transformer having a primary winding and a secondary winding across which secondary pulses of first and second polarities and first and second magnitudes are developed when input pulses of opposing polarities are provided to the primary winding;a full-wave rectifier bridge having first and second nodes coupled to the secondary winding and third and fourth nodes;first and second capacitors connected in series between the third and fourth nodes;first and second controlled switches coupled between a control electrode of the power switching device and the first and second capacitors, respectively, each controlled switch having a control electrode coupled to the secondary winding of the transformer;wherein control current is drawn from the control electrode of the power switching device through the second controlled switch to the second capacitor in response to the development of a secondary pulse of the second polarity and the second magnitude, at which point charging current is provided to the first and second capacitors from the secondary winding of the transformer; andwherein the control current is provided by the first capacitor to the control electrode of the power switching device through the first controlled switch in response to the development of a secondary pulse of the first polarity and the first magnitude, the first capacitor being discharged thereby until a voltage magnitude of the first capacitor discharges below the first magnitude of the secondary pulse of the first polarity and the first magnitude, at which point charging current is provided to the first capacitor from the secondary winding of the transformer.