Figure 1 Royer Oscillator-based Transistor Power Supply. A note about the transformer. It has two 24 volt center tapped windings and a high voltage winding either center tapped or not. Such a transformer may not exist. This is likely the reason why there are no values or part numbers given for the parts. The plus twelve volt connection goes to the center tap of the upper primary winding. The top of the upper winding goes to the collector of the left hand transistor. The lower end of the upper winding goes to the collector of the right hand transistor. The emitters of both transistors are grounded. One end of a resistor connects to the plus twelve volt point. The other end of this resistor goes to one end of another resistor. The other end of the second resistor goes to ground. The junction of the two resistors goes to the center tap of the lower primary winding. The upper end of the lower winding goes to the base of the left hand transistor. The lower end of the lower winding goes to the base of the right hand transistor. The high voltage secondary winding is not center tapped. Each side of the winding goes to the AC inputs, anode and cathode, of a bridge rectifier. The negative output of the bridge, two anodes, is grounded. The positive output, two cathodes, goes to the junction of a capacitor and filter choke. The other end of the capacitor is grounded. The other end of the filter choke goes to B plus point. The B plus point also goes to ground through another capacitor. This completes the description of figure 1.
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