| 摘要 |
This DC converter circuit is preferably suitable for vehicles with a rheostat-controlled brake powered by the electrical system, said vehicles being fed from a DC voltage system (DC voltage source G), and having a DC drive (A) or a rotary current drive with inverter connected upstream. The DC converter circuit has two parallel branches: one brake branch with brake resistor (RB) and brake thyristor (TB) located in series and a main branch with the actual DC converter. When the DC converter is designed as turn-on and turn-off electronic switches (gate-turn-off thyristor GTO) without their own turn-off device, the conductive brake thyristor (TB) is no longer also turned off when the electronic switch (GTO) is disabled. Therefore, in order to turn off the brake thyristor (TB) an auxiliary turn-off branch, consisting of the series connection of an auxiliary reactor (LH) and an auxiliary capacitor (CH) is provided parallel to the brake resistor (RB). When the electronic switch (GTO) if fired, the brake thyristor (TB) is turned off by the flow of current produced in the auxiliary turn-off branch. <IMAGE>
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