High voltage source providing continuously regulated output voltage, preferably for supplying low-power ion and electron beam machining and evaporating apparatuses

Claim 1

In a high voltage source providing continuously regulated output voltage, preferably for supplying low-power particle beam machining or evaporating apparatus, comprising: first and second high voltage output terminals across which a high voltage is to be supplied; first and second low voltage input terminals across which a low voltage is to be supplied; an error signal processing circuit having an output terminal; a control circuit having an input terminal connected to said error signal processing circuit; a driving circuit having first and second control signal input terminals respectively connected to first and second push-pull control signal output terminals of said control circuit; a high voltage rectifier having first and second output terminals, said first output terminal of said high voltage rectifier being coupled to said first output terminal of said high voltage source and to a voltage signal input terminal of said error processing circuit by way of an output voltage-sampling divider, and said second output terminal of said high voltage rectifier being coupled to said second output terminal of said high voltage source via a capacitor and to a current signal input terminal of said error processing circuit, said driving circuit being coupled to said rectifier via a high-voltage transformer having first and second push-pull primary windings; the improvement wherein said driving circuit comprises: first and second driving amplifiers respectively connected to said first and second control signal input terminals; first and second controlled switches each having a first input terminal connected to a respective one of said driving amplifiers, a second input terminal connected to ground, and an output terminal connected to said high voltage transformer, said first input terminal of said first controlled switch being coupled to an output terminal of said first driving amplifier, said first input terminal of said second controlled switch being coupled to an output terminal of said second driving amplifier, said output terminal of said first controlled switch being coupled to one end of said first push-pull primary winding, and said output terminal of said second controlled switch being coupled to one end of said second push-pull primary winding; non-linear choke coil means comprising first and second transformers each having a primary winding and a secondary winding, said primary windings of said first, second and high voltage transformers being connected in series, a first junction along the line connecting said primary winding of said first transformer to said primary winding of said second transformer being coupled to said first low-voltage input terminal, and said secondary windings of said first and second windings being connected in series, a second junction along the line connecting said secondary winding of said first transformer to said secondary winding of said second transformer being coupled to ground, the end of said secondary winding of said first transformer not connected to said second junction being coupled to a third junction via a first RC circuit and to said first low voltage input terminal via a first diode, said third junction being connected to ground, and the end of said secondary winding of said second transformer not connected to said second junction being coupled to said third junction via a second RC circuit and to said first low voltage input terminal via a second diode.