Abstract:
A modular cascaded reversible polarity ultrahigh DC voltage supply system is described wherein modular DC voltage power supply units are vertically stacked one upon another and connected in cascaded series relationship to form an ultrahigh DC voltage supply. Each of the modular units, as shown, includes a three-position switch electrically connected in each of the modular power supply units to ''''ground'''' and then to reverse the polarity of the system output voltage, such that the whole electrical load is grounded between polarity reversals. A control is provided external of the vertically stacked modular units and couples to each of the switches at vertical intervals to simultaneously control the polarity positions of the respective switches for reversing the polarity of the system voltage. A grounded intermediate terminal is effectively located in each of the switches to ground the system and also to ground the load connected to it before the polarity of the voltage applied to the load is reversed. The ability to ground the load and then to apply a reversed ultrahigh DC voltage is advantageous for use in test systems, and the modular construction enables various predetermined ultrahigh DC levels to be obtained conveniently by assembling the desired number of stacked modular units.