I have to develop a push-pull with two outputs (+V, -V) where the feedback is at the positive output and the negative output is uncontrolled.
input voltage range is 10V...20V
frequency at the transformer is 100kHz
output voltage range is ±20V...±220V
load varies from 6MΩ to 6kΩ per output.
transformer turn ratio is 25.
I build a prototype where the LC filter at each output is 1mH,2μF.
I notice that when I load the controlled output +V with 6kΩ and the uncontrolled -V output is connected to 6MΩ
the controlled output remains at 200Volt (because I set the working point a 200V) but the uncontrolled output goes to a very high voltage (250V ...500V).
Can someone help me and explain this fact ?