Buck Converter

The need for a buck converter circuit was mentioned before:

https://wb9kzy.blogspot.com/2025/04/an-ongoing-need.html

I did finally order an MC34063 chip but in the mean time I found this module:

It's an LM2596 based design, very popular and has a schematic similar to this:

not sure on the inductor, it might be 47 uH, also there are two ceramic caps on the board not shown on the schematic

source: https://www.mpja.com/Adjustable-15-37V-DC_DC-Buck-Converter/productinfo/36705%20PS/

Basically I should just be able to add a power input connector and a USB output connector and stick it all into a shielded box.  It may be necessary to add some filtering on the input and output to prevent noise.  It oscillates at roughly 50 kHz so there could be plenty of spurs all over the spectrum.  It will supposedly supply up over 1A at 5V from a 12V supply so it should be OK for battery charging.

I'm also thinking of adding some kind of reverse polarity protection to the input.
 

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm