Circuit arrangement for relieving electronic pairs of arms of the dissipation power during the turn-on and -off process

摘要

Apart from the elements turn-on limiting reactor (Le) and turn-off limiting capacitor (Ca), which are necessary in any case in turn-on and -off networks of an electronic pair of arms formed by a controllable switch (Th) and a first freewheeling diode (Df1), a third energy store - a unipolar storage capacitor (CSp) - is provided which temporarily buffers the energy of the two reactive elements (Le) and (Ca). The energy of this storage capacitor (CSp) is delivered into the load via a second freewheeling diode (Df2) after the turn-off process. The turn-off limiting capacitor (Ca) is recharged after the controllable electronic switch (Th) has been turned on, the turn-on limiting reactor (Le) acting as a ring-around reactor. A turn-off limiting diode (Da), a blocking diode (Ds) and the second freewheeling diode (Df2) provide a circuit path which does not allow the voltage at the controllable electronic switch (Th) to rise above the direct voltage (UD). <IMAGE>