I'm completely new to electronics and I have a simple project for which I can't find a clear solution. I've been googling various keyword combinations for a few hours and haven't managed to get any further. I'm happy to be directed to relevant resources or for someone to help me figure it out.

Here is my project. I recently got a Bluetooth receiver for my old desktop speakers to be able to use them wirelessly. I built the speaker cases myself out of laser-cut plywood and I would now like to put the Bluetooth receiver inside one of the cases so it looks like the speakers support Bluetooth natively. How can I merge the two power supplies into one?

Here are the technical data I have:

• The speakers need 5V 1.5A input
• The Bluetooth receiver needs 5V 150mA input
• I need a solution that works for European current standards

So far I've managed to piece together that I should get an adapter that can do at least the sum of both input currents, namely 5V and at least 1.65A. What I can't figure out is how I can split that current into 1.5A on one side and 150mA on the other. Are there ready-made solutions out there? Should I design my own circuit? What kind of electronics components should I use?

Any help is much appreciated.
Thanks,
Yohann

 

Welcome to AAC!

What I can't figure out is how I can split that current into 1.5A on one side and 150mA on the other.

This is a common misconception among novices. You don't need to do anything; each device will take only what it needs.

Consider your home electrical wiring. When you plug fixtures of varying wattage into the same circuit, do you have to do anything to "share" the current among them? No. They just take what they need. When the total is more than the circuit can support, a breaker trips or a fuse blows.

Are there ready-made solutions out there? Should I design my own circuit?

No ready made solutions because there's no problem.

What kind of electronics components should I use?

You just need a splitter with compatible connectors.

Here's one sold by Home Depot:

EDIT: cropped picture

 

.....I should get an adapter that can do at least the sum of both input currents, namely 5V and at least 1.65A.

For good derating, and considering that some supply ratings are on the optimistic side, you should get an adapter with at least 50% higher rating then the max current you need or 1.5 * (1.5+.15) ≈ 2.5A@5V.

 

I really hope that your responses show up on Google next time someone asks a similar question. Thanks a lot for the clear explanation!