High voltage stabilizing circuit

A high voltage stabilizing circuit comprising:

• rectifying and smoothing means for rectifying and smoothing commercial alternating-current power and thereby providing direct-current input voltage;
• switching means having a switching device for interrupting said direct-current input voltage for output;
• a parallel resonant circuit on a primary side formed so as to convert operation of said switching means into voltage resonance type operation;
• a high voltage output transformer having a primary-side winding to which switching output of said switching means is transmitted and a secondary-side winding closely coupled to the primary winding for inducing a required high level of stepped-up alternating voltage;
• high direct-current voltage generating means supplied with said stepped-up alternating voltage for generating and outputting a required high level of direct-current voltage;
• and
• constant voltage control means for controlling said high direct-current voltage to a constant voltage by changing switching frequency of said switching device according to level of said high direct-current voltage.