摘要 |
In a quarter-bridge circuit for high currents the total current is subdivided into a plurality of parallel current paths. In each current path a semiconductor component (5.1, . . . , 5.n, 6.1, . . . , 6.n) that can be turned off via a gate, a freewheeling diode (7.1, . . . , 7.n, 8.1, . . . , 8.n) located opposite a midpoint, and a clamping capacitor (9.1, . . . , 9.n, 10.1, . . . , 10.n) are arranged in parallel with the freewheeling diode (7.1, . . . 7.n, 8.1, . . . , 8.n) and the turnoff semiconductor component (9.1, . . . , 9.n, 10.1, . . . , 10.n) in such a way that the respective freewheeling path has as minimal an inductance as possible. Provided between a load terminal (3) of the quarter-bridge circuit and each midpoint of a current path is one inductor (L11.1, . . . , L11.n, L21., . . . , L21.n) each which limits the rate of current rise, so that a current rush caused by an operating delay does not overload the turnoff semiconductor component (9.1, . . . , 9.n, 10.1, . . . , 10.n). Each current path is preferably realized by means of a separate module. The quarter-bridge is suitable for series connection, equally as a part of a bridge circuit or of a chopper.
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