| 摘要 |
The circuit arrangement for limiting a voltage to a desired value is preferably intended for use in railway protection systems in which there is a risk of high influencing voltages occurring in the signalling device system in the event of contact-wire short circuits in the vicinity of railway substations. The circuit arrangement thus consists of a threshold circuit which consists of one or more series-connected zener diodes (ZE) in conjunction with a resistor (RV), this series circuit being supplied by means of a surge-proof constant-current source (KE). This circuit is connected to the voltage to be limited and controls a DC power amplifier having a predetermined number of power transistors (T2, T3, etc.), in conjunction with a load resistor (RL). <IMAGE>
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