Patent ID: 6486612
Filing Date: 2002-11-26
Classification: H01L,H05B

Abstract:
A piezoelectric transformer control circuit comprising:oscillation means for generating an oscillation signal in accordance with a control voltage, driving means for driving a piezoelectric transformer by an AC voltage generated in accordance with the oscillation signal from said oscillation means, control means for detecting a load current of a load connected to an output side of said piezoelectric transformer and for controlling an oscillation frequency of said oscillation means so as to keep the load current substantially constant, first detecting means for detecting an output voltage from said piezoelectric transformer, and protective means including second detecting means for detecting an open state and a short-circuiting to ground on an output side of said piezoelectric transformer based on comparing the detected output voltage with first and second predetermined values, so that said protective means controls the oscillation signal generated by said oscillation means in response to the comparison.