Help me understand this linear supply circuit.

[прямо]

Was looking for a simple CV CC linear supply to build and came across this one.

https://oshwlab.com/svalentin544/lab...ply-0-38v-0-5a

I etched the provided board design and populated it.

The output voltage adjustment works.

The output current adjustment however, doesn't behave like I expected it to be. If PR2 is going clockwise, the output voltage decrease. Adjusting R5 has no effect.

I don't have a load connected to the output at all.

Can someone explain how the current adjustment work? is it supposed to behave like that?

[прямо]

Nevermind. Circuit doesn't work at all regardless of what I do.

I set the output voltage at 12V, and connected a 12V fan as a load. Voltage immediately tanked to 2.3V

[harp]

"I etched the provided board design and populated it."... on picture there is some to92 transistors rotated against silk screen (hopefully in that position it work)... have you check that?

[Agent24]

What do you expect it to do?

If you limit current, the voltage has to decrease to keep the current limited.
If you have a load that is trying to draw more than that set current, anyway.