Hi,

I am in the process of creating a DIY Bluetooth speaker which is powered by DC 12v 2a power supply. I want to incorporate a Qi wireless circuit board to charge my phone on top of the Bluetooth speaker when on. I have a 9v 2a 10w (Qi charger used). If I create a separate circuit feeding off the same power supply in parallel with a 12v to 9v 2a converter (12v to 9v 2a converter) will this work? Also, where do I split the circuit from and will stepping down the voltage on this partitioning affect the rest of the circuit, as I need this to remain constant at 12v for the Bluetooth amp board.

Kind Regards,

Luke

 

You have to think about the total power requirements here but might be possible.
The 12V 2A power supply gives you a total of 24W.
The Qi charger is 10W - presumably that is 5V (USB) at 2A. Or is it 9V at 2A, that is 18W?
What's left 10W or possibly only 6W is remaining for your audio.
To get the power for the Qi charger from the 12V supply you need to use a switchmode dropper otherwise you will waste too much power. Something like this to produce 9V or this (5V) with a USB socket built in.