I wanted to have as compact, small and flexible a laboratory power supply as possible with a maximum output voltage of 32 V and 5 A. It was especially important to me that it should be completely passively cooled. So I can use it overnight to charge different batteries without being disturbed by the noise of the fans.
I have decided to use the DPS3005 laboratory power supply controller from R&D based on very good experience. This offers a good electrical output power of 160 W with an amazingly good control accuracy. Very pleasant is that the voltage can be adjusted to 10 mV and the current to 1 mA. I had previously built a larger laboratory power supply with the big brother DPS5020. This has an output power of 1 kW with a maximum of 50 V and 20 A.
As a voltage source I chose the simple but perfectly adequate switching power supply WX-DC2416. With 180 W electrical output power, 36 V and 5 A, it has the right parameters to supply the lab power supply controller. In addition, it is completely passively cooled as desired.
I provided two banana jacks and two pairs of speaker cable terminals to tap the power. I saw the latter at a Russian tinkerer and found the idea for quick tests with low current ingenious. This eliminates the need to search for the test lead and alligator clips.
The DC voltage circuit is fused with 7.5 A and the mains voltage with 1 A.
3d printing of the housing
As a basis for the box I used the “The Ultimate box maker” .scad-customizer of the Thingiverse user “Heartman”. I have chosen the dimensions of the housing so that the power supply has enough space and on the front clearly the controler and banana jacks have space.