# Powering 2 Devices from 1 Adapter

Discussion in 'General Electronics Discussion' started by Last_Mavrik, Nov 15, 2012.

1. ### Last_Mavrik

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Nov 15, 2012
Hey everyone,

This is my first post, and I'm not precisely an Electronic's Genius, but I have plenty of soldering experience, basic Electronic Priniciples training, and a descent amount of electrical troubleshooting experience. What I lack is knowledge of circuit boards and the components there-in, so I find myself here with the following scenario:

I need to run 2 separate devices that each reaquire a 12 Volt DC input. Both are in close proximity to eachother and are wired into the same controll box. Currently, I have a pair of 12vDC power adapters feeding into separate power jacks in said controll box, and then to their respective devices. My question is:

Q: What would I need to run both devices from a single power jack without risking overloading either device? (E.g. what voltage adapter and/or internal electrical components to safely split the DC input between the two.)

Last edited by a moderator: Nov 17, 2012
2. ### CocaCola

3,635
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Apr 7, 2012
The devices will only draw the current they need... You need a single power supply that supplies in excess of the combined draw of both devices...

Say for instance device one has a 12V @ 750mA adapter and device two has a 12V @ 1A adapter you should choose a 12V @ 2A (12V @ 1750mA minimum) supply to run them both...

Mind polarity and mind if they are both DC...

3. ### Last_Mavrik

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Nov 15, 2012
Makes sense. To be a little more specific, it's a camera system, and both the Camera assembly and the monitor take identicle 12v DC power adapters. I'm not sure of the Amps, but that would be because I took Electronic Principles over 5 years ago and haven't used power measurements beyond ##v DC since.

Thanks again for that. I'll check the draw of both and go from there. Forgot current is Amps, not Volts, so I thought I would need something like a 16v power supply and resistors/diodes to divide the power safely. Ameture moment. Thanks for that!

Last edited by a moderator: Nov 17, 2012
4. ### userqq

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Oct 4, 2012
When you think about it, it should work because in a car the battery is powering differrent things at once. I think the main danger here is that if you happen to accidentally overpower one of the devices then maybe it could get burned out.

5. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,448
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Jan 21, 2010
That bit makes sense.

And that bit doesn't.

6. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012

You don't have to know exactly what each one draws. Since they both use identical power packs just read the current specs (it's printed on them) from one of them and multiply it by 2.

Chris

7. ### Last_Mavrik

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Nov 15, 2012
Thanks for the advice everyone. I'll inform my boss, since he orders things and I do the technical part, and let you know if all goes well, or if something doesn't quite work as advertised. I checked the current adapters, and they're rated at 12v DC 1.5A, so if I can find a 12v DC 3A adapter everything "Should" work.

Last edited by a moderator: Nov 17, 2012
8. ### CDRIVEHauling 10' pipe on a Trek Shift3

4,960
651
May 8, 2012
Just make sure that you wire the polarity correctly.

Chris

9. ### Last_Mavrik

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Nov 15, 2012
Not a problem. I've build nearly 100 of these cameras since starting this job, so connecting the devices to one jack is simple. Just didn't know what voltage/Apm adapter would be needed.

Last edited by a moderator: Nov 17, 2012