Patent ID: 6611148
Filing Date: 2003-08-26
Classification: G01R,H04B

Abstract:
An oscillator circuit comprising:a transformer including a primary winding and at least one secondary winding, the secondary winding to be coupled across an external load; first and second bipolar junction transistors connected in a â€œpush-pullâ€  operating mode in an oscillator loop and coupled to the primary winding of the transformer for producing a high frequency voltage, the primary winding having two ends each respective one of which is coupled to a respective one of the collectors of the first and second bipolar junction transistors; first and second field effect transistors respectively coupled in parallel with the first and second bipolar junction transistors; and means for actuating the first and second field effect transistors to respectively conduct substantially synchronously with the first and second bipolar junction transistors upon excitation of the transformer windings and upon an oscillator signal in the oscillator loop reaching a predetermined voltage, whereby the current conducting through the primary winding is substantially shunted from the bipolar junction transistors to the field effect transistors to significantly reduce power loss otherwise occurring if the current were conducting through the bipolar junction transistors alone.