I'm looking to modify a power supply to get a little more voltage out of it.
The 19.5V version of my power supply's schematic is
here (not sure if I should attach it, it's watermarked).
I have the 20V version. The primary differences I see are on the feedback circuit (lower right). R301 R315 and R306 are different values on mine, presumably to increase the voltage to 20V. I want to go to 23V or so. The output capacitors are rated at 25V so kinda questionable even with the stock configuration. 35V would make more sense but I don't think I can physically fit them inside the case.
At first I thought it would be simple, just modify R301 but then I realized that would also change the 5V rail(?) and that can't be increased without possibly damaging something. Now normally I could experiment and test things to see how it's going to work but this is complicated by the fact that there are multiple parts all interacting and it's not possible to test individual modules(?). I think I might try tweaking R301 a very tiny amount and see what happens. Probably decrease the resistance and see how much that lowers the 5V. Though testing the 5V side is not my idea of fun because it's on the high-voltage side with tiny parts.
Is there any way to calculate the approximate resistor values I would need so I don't have to test a live system?