Following my online seller’s description, let me call it as “DC-DC Boost and Buck Voltage Converter LM2577-LM2596 Module”. But before committing ... The PCB is marked as XW036FR4. This is the ...

If you’re using a LM2596 DC-DC converter module to power your gadget, you can add a touch sensitive soft switch for literally pennies. The trick is utilizing the enable pin on the LM2596.