High efficiency switching drive for a resonate power transformer

Abstract

A high efficiency switching drive for a resonate power transformer having the ability to maintain a constant output voltage over a wide range of source voltage variation while maintaining good power conversion efficiency is provided. A transistorized class-C oscillator has means to saturate the transistors during conduction time to allow the transistor voltage to remain small as opposed to a current source as in the conventional class-C oscillator.

The invention is claimed in accordance with the following: 
     
       1. A circuit for improving the efficiency of an energy conversion apparatus, comprising: a resonate transformer having primary windings and secondary windings electromagnetically coupled thereto for converting the energy;   means, coupled to said primary windings, for storing energy .[.developed by said primary windings.].;   first switch means coupled to said means for storing energy, said first switch means having a first condition and a second condition;   means for impressing a potential of an external energy source across said primary windings and said means for storing energy in said first condition of said first switch means; and   second switch means coupled to said primary windings and operatively disposed across said means for storing energy in said second condition of said first switch means for impressing energy stored in said first condition to said primary windings thereby improving efficiency of the apparatus.   
     
     
       2. The circuit according to claim 1 further comprising feedback means operatively disposed between said second windings and said first switch means for controlling said first switch means. 
     
     
       3. The circuit according to claim 2 wherein said feedback means determines said first and second conditions of said first switch means. 
     
     
       4. The circuit according to claim 1 wherein said first switch means defines a blocking oscillator containing an oscillating transistor. 
     
     
       5. The circuit according to claim 1 wherein said means for storing energy defines a transformer winding connected to said primary winding. 
     
     
       6. The circuit according to claim 1 wherein said second switch means defines an amplifier means including a switching transistor.