A Tripping Circuit for a Multi-stage Surge Generator

The sphere gap in the first stage of an existing multistage surge generator has been replaced by two equal gaps in series by introducing a third sphere. By applying an impulse to the centre sphere when the gaps are charged nearly to the breakdown voltage, breakdown can be initiated at a desired instant. This tripping impulse is generated by a thyratron becoming ionized when a low voltage impulse is applied to its grid, and simultaneously to the sweep circuit of the oscillograph. On account of the inherent time delay in the ionization of a thyratron, the sweep circuit is initiated before the surge generator. A delay cable in the measuring circuit is thus rendered unnecessary. Visual or automatic methods of controlling the output voltage of the generator can be used.