XL4016 constant voltage constant current module

It is pieced together using some parts, so the choice between SMD and direct plug-in is very unreasonable;
the WXD potentiometer used is very bad, 3 out of 5 are broken, and it is large in size. Unfortunately, I can't find a smaller and more reliable multi-turn potentiometer;
the voltmeter used is a 0.28-inch three-wire DC meter head. It is recommended to choose a decimal point that can be shifted, which can improve the display accuracy at low voltage and low current.
 
Reference circuit:
 
An on-off switch is added so that the
 
12V output can be completely disconnected when power is needed:
SW waveform:
 
1A constant current output:
SW waveform:
 
Close the on-off switch with load:
 
Back:
 
It can be found that the SW foot Snubber composed of R8 and C13 is not welded. This is because the SW waveform is perfect and there is no overshoot and undershoot;
and the absorption circuit composed of R4 and C11 has been replaced by TVS. Readers can decide which circuits to install according to the actual input voltage and cable length.
 
After installation, please adjust the pre-adjustment potentiometer on the back to make the voltmeter display consistent with the standard instrument (such as a multimeter)
 
2023/3/29 Debugging results:
(24V input 16.5V 5A output)
SW node:
output voltage;
accompanied by severe noise (about 3KHz)
 
(24V input 16.7V 0.5A output)
SW node:
 
identified as subharmonic oscillation, but the author does not have a slope compensation method for the integrated switching converter, so give up the repair