Patent ID: 6166922
Filing Date: 2000-12-26
Classification: H02M

Abstract:
A current resonance circuit including a serial circuit of coil and capacitor, first and second switching elements and oscillating circuit in which said first switching element is connected between a DC voltage source and one end of said serial circuit, the other end of said serial circuit is connected to the reference potential point, said second switching element is connected in parallel to said serial circuit and said oscillating circuit generates a couple of AC signals including phase difference of about 180 degrees by oscillating in the frequency depending on a control current or control voltage and respectively supplies these AC signals to said first and second switching elements as the ON/OFF control signals;said current resonance circuit comprising:current detecting means for detecting amplitude of current flowing toward the connecting point of said first switching element and said serial circuit through said second switching element;comparing means for comparing amplitude of current detected by said current detecting means with the reference value; andoscillation control means for controlling said control current or control voltage supplied to said oscillating circuit in order to raise the oscillation frequency of said oscillating circuit when amplitude of current detected by said current detecting means is smaller than said reference value as a result of comparison by said comparing means.