Transient-free stabilised high tension voltage supply - for an electro-magnetic isotope separator

摘要

The circuit supplies >=1 kV typically 70 kV DC. The voltage is controlled at this value, filters protect the control circuits against transients in the mains, and other filters protect the mains against transients from the isotope separator. The rectified voltage from the transformer is applied to the isotope separator circuit through a triode, whose grid potential provides the stabilising control. a fraction of the target voltage is compared with an (adjustable) standard (generated with temp- controlled Zener diodes) and the difference amplified the resulting DC signal is interrupted at 300 Hz transformed rectified and applied to the grid of the control triode. The transformer used has only a single turn primary: this prevents transients being fed back from the separator. The control circuits are protected against transients in the mains by a filter using ferrite blocks through which parallel leads pass in (a) the same and (b) opposite directions, the filter includes also capacitors and varistors. Similar filters protect the mains against transients arising in the isotope separator.