I need to provide power to a mic that has 3.5mm jack. All of the external phantom power supplies are for XLR. Does anyone know of a good solution.
I'd be extremely surprised if your mic needed phantom power with only a mini jack. Phantom power is 48V and it would likely fry your mic.
See this thread for some more details about what power you might need;
Usually mics that need phantom power come with an XLR plug, as phantom power does not usually get fed through jack plugs/sockets. Especially 3.5mm jacks. Having said that, some of my minidisc recorders provide some sort of power to some mics, but I doubt it's the sort of phantom power(48v) that's available on mixers, etc.
You want to use a USB power injector, like this: https://www.amazon.com/gp/product/B00I6ILPPC/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1