Power supplying device for the operation of a gas discharge container

Claim 1

In a power supplying device for the operation of a gas discharge container, particularly an ionitriding container, containing metallic workpieces to be treated, said device being supplied from an alternating-current power source, comprising a transformer, the primary circuit of which is connected to said power source, a rectifying device comprising controlled rectifiers, the input of said rectifying device being connected to the secondary circuit of said transformer, the output of said rectifying means providing direct operating voltage between said workpieces and the housing of said container, a monitoring device connected between said workpieces and said container for monitoring said operating voltage and the operating current, the output of said monitoring device being connected to the input of a regulating and switching device for said operating voltage, the output of said regulating and switching device being connected with said rectifying device in combination, the improvement comprising: a. said rectifying device comprisIng a full-wave bridge having four controlled rectifier elements, performing across one bridge diagonal a full wave direct operating voltage while the other diagonal of said bridge is connected to the terminals of said secondary circuit of said transformer, pairs of controlling electrodes of said rectifiers being interconnected and connected to said output of said regulating and switching device; and b. an inductance connected in series with said primary circuit such that the start of each wave of the operating voltage following every zero passage is retarded by a period of time in the range of 2 - 7 milliseconds.