Hello,
I'm trying to use MC33063 chip to build a DC/DC converter (input between 10 and 35V, output 19V, 100W). I have found a demonstation board schematic I have modified.
Indeed, my load requires 19V/100W, thus, all power transistors are replaced by Darlingtons. Now, myu schematic is :
and I don't understand why it doesn't work as expected. Without load (or with a tiny load, typically less than 5W), I obtain a clean 19V output. But when current increases, MC33063 stops and output falls to 0V. I have tried different polarization for power transistors without any success.
Any idea ?
Best regards,
JB
