AZDeliveryCompatible with MT3608 DC-DC Power Supply Adapter Step Up Module compatible with Arduino including eBook

I bought these to boost 9V from a PP3 battery to 12V for a guitar FX box project of mine.They work flawlessly! See my photo showing 12V output from the 9V input.Note, you have to rotate the multi-turn trimmer anti-clockwise lots of turns before getting any voltage boost. That's by design and is perfectly normal!Eventually the output voltage rises steeply and the trimmer becomes very sensitive.Those claiming these over-heated, blew up etc are doing something very wrong!These are simple, nicely manufactured devices based on a tried and tested circuit built around the MT3608 chip.There's not much that can go wrong except perhaps user error! I'm being polite saying 'perhaps' here!Don't exceed the maximum input voltage!Don't expect a huge amount of output current!Don't short the output terminals!!Connect the input voltage to the input and not the output!!!A real unexpected plus point is that AZDelivery send you the manual etc by email as soon as the order is despatched from Amazon.I think that's great customer support myself. Not many suppliers do that in this field.Anyway, I'm very pleased with my purchase.Excellent value and an excellent unfussy product which does exactly what is claimed.Recommended!

I reviewed this and said only one if three worked. Update - the third one failed as well. Amazon happy to refund. Anyone know a voltage doubler that actually works?

Ordered a pack of three, none of which actually works. "great stuff".