So i have these two circuits i want to run off one power source ( 9v battery ) One circuit is going to a step up dc to dc converter 9v to 12v drawing 300ma. And the other circuit is going to draw 9v at 10ma. Will this work? or will they want to even out and the battery will try to send 300ma to the 10ma circuit. I plan to wire in parallel. I think it should work...? Im new to electronics im just doing this for fun. This is probably a stupid question! Thank you!

 

It will work fine as long as the battery isn't one of these - it will supply 300mA only very briefly.

 

I used battery just to simplify the question im using a power supply that can handle it. Thanks!! I love this site.