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Powering multiple DC devices

Posted: Fri Mar 18, 2016 8:08 pm
by pathead
Sorry I did not think this fit under any other category...

I'm using the Pi to build a remote sensor communications box and I have a few other things in there with varying power requirements and I was wondering if there was an easy way to power them all without having to use wall warts.

Pi - 5V, 2A?
Modem - 9V, 1A
Sensor Device - 24V, 0.5A
Ethernet Switch - 12V, 0.5A

Would something like this work for the 24V and 12V devices if I reduced the voltage on one of the outputs? ... =mdr-40-24

Thank you!

Re: Powering multiple DC devices

Posted: Tue Mar 22, 2016 9:57 pm
by HiroProtagonist
That's quite an array of voltages you've got there...

You don't mention what your input power is - mains? Battery? Solar? RTG?

Are you particularly concerned with price or efficiency?

Do all of these devices require regulated power, or do some of them have internal regulation?

Have you investigated to see if there is a hidden commonality in any of the power requirements [e.g. is the modem regulating down to 5V internally]?

Re: Powering multiple DC devices

Posted: Tue Mar 22, 2016 10:35 pm
by mosespi
You can use a suitable adapter to your highest voltage and power requirement, in your case looks like 24v and about 40 watts. And then use DC-DC buck regulators for the lower voltages.. like these.. ... B018JWCX8M

Note, that most of those DC-DC converters are not really built for continuous power at their listed rating. The one above says 3A, but I would half that value for continuous use. Good news is those ratings you read off of most devices are usually peak power use, and average power use is likely a bit less, you need to measure to be sure.