Hello. I'm working on an Active Clamp Current Mode Forward Converter and I have two questions.
1.When I'm calculating the two resistors that set the slope compensation there is a variable named : "
The down slope of the output inductor current waveform reflected across the primary side current sense
resistor". I can't understand what this means. I have calculated the slope of each output and used the average of that for calculations. Have I interpreted the variable name correctly?
2.My primary problem is that the circuit on it's minimal load 2W on the 15V side and 1W on the 7.5V side and maximum input voltage (30V) makes a high frequency noise when I touch one end of the secondary winding. And with the calculated values it makes that noise without me touching it. What makes this circuit so unstable? Or is it actually instability because I have tested it with a voltage of 1000V between the two grounds as the application requires and it worked just fine.

 

I found a guide from Texas Instruments for this calculation and using the guide I got a very precise regulation of both outputs even with asymmetric loads this leads me to believe that the slope compensation wasn't the problem but the high frequency noise didn't go away, in fact it got worse now it appears 3 times over the input voltage range (18-30). This noise appears at a certain input voltage, then disappears with another, I cant make sense of it.