Stepdown buck converter

[skeletonghost]

Hi, I recently got my hands on a dozen or so DC-DC smd stepdown regulators from aliexpress. I figured this would be a cheap and faster way of building power banks then making a bunch of l7809 circuits on vero as I normally would.



I wired them up as I expected you would. Input 12v to the In+ and Output connected to Out+ (gnd to gnd) and nothing useful appears to happen? It steps down to around 8.1v but the trimpot has seemingly no effect. Is there a trick to this? Is there something I am missing? Or is it just shoddy aliexpress chips. Ideas?

[ξεναγος νεκροπολης]

i was just about to get some bipolar supply modules like this!

http://www.ebay.com/itm/232026823414?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

haha! i knew they might never work!!!
but i'll get them anyway....who knows!

[skeletonghost]

I would say buyer beware. I've hooked it up more or less how I'd expect but with no effect. I've only tested 2 so maybe a few in the batch will work :P