摘要 |
A full wave bridge inverter includes four switch arms, each including N bipolar, parallel transistor switching elements. During a first interval, emitter-collector paths of all transistors in the first and second arms are forward biased so current flows in a first direction from a DC source through a bridge diagonal. During a second interval, emitter-collector paths of all transistors of the third and fourth arms are forward biased so current flows from the source through the diagonal in a second direction. The transistors have a tendency to be activated into the conducting and cut-off conditions at different times, and different transistors have a tendency to conduct differing amounts of current while forward biased. To overcome these tendencies, there are 2N2 transformers, each including first and second windings having like numbers of turns. The first windings of N of the transformers are connected in series with the emitter of the ith transistor of the first arm; the second windings of these N transformers are connected in series with the emitter-collector paths of each of the transistors of the second arm, where i=1, 2, . . . , N. Each first and second winding is connected to only one element of the first and second arms, respectively. Similar transformer connections exist between the transistors of the third and fourth arms.
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