Hello! I made the power supply from the attached schematic.
I tested it using the oscilloscope, using a PSU shorter, which is a circuit with LM555 that is generating pulses through a mosfet gate and is connecting and disconnecting a load. ln case of short circuit testing the load is 0 ohms, while testing with load, the load is 7.8 ohms. The set output voltage of the PSU is 25V. The rectifier is not present into schematic, but it is connected between the 30V ac transformer and filter capacitors.

The results are:
1. DS0018 = with 0 ohms at PSU shorter, and the yellow trace, CH1, on the output of the PSU, CH2, is the output of the PSU Shorter pulse generator.
2. DS0019 = with 0 ohms at PSU shorter, but with the probe on the R_Shunt resistor (on the 2 0.33R resistors).
3. DS0020, 21 = with 7.8 ohms at PSU shorter, and the scope probe on the output of the PSU (yellow trace) and the CH2 probe (blue trace) on the output of the PSU shorter pulse generator.

Please have a look at the screenshots and tell me what you think.
I don't understand the response of the PSU from DS0020 screenshot, can you please explain this response ?

 

Hi mike,
For starters make C4 at least 1000uF.
E

 

Your scope appears to be AC-coupled. Wouldn't DC-coupled be better here?
I think what you're seeing in DS0020 is the PSU response to a step change in load. The output caps take a finite time to reach a stable voltage.