Two 15VDC+/- PSUs as one +/-30VDC?

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megaohm
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Two 15VDC+/- PSUs as one +/-30VDC?

Post by megaohm » Tue Sep 03, 2019 4:04 pm

I have a bunch of Power One, Condor, Lambda linear suppies.
All +/-15VDC. Very typical of MOTM, DotCom, others.

I want to hook two together to get a +/-30VDC supply so I can test out an ADR rack and a bunch of SCAMP modules (Audio Design and Recording is the brand).
These racks came with a +/-28VDC external supply which I do not have. Most cards use 7824 and 7924 regulators.

This is not for a permanent solution. Simply to test out the rack and find which cards may need repair.

I know I can hook up two DC supplies to get a larger output but I have only seen this with single polarity PSUs. Is this doable with these +/- type of supplies?

The two I am looking at are both Power-One HAA15-0.8-A
(+/-15VDC at 800mA)
My thinking is the -OUT post of one PSU connects to the +OUT post of the second PSU which is now the common node. The COM posts of either PSU are not used.

Doable or no?
If yes, what is the poper way to apply AC to these two?
Anyone here do this before?
Any details or gothchas I'm missing?

Thanks
www.MegaOhmAudio.com

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Graham Hinton
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Re: Two 15VDC+/- PSUs as one +/-30VDC?

Post by Graham Hinton » Wed Sep 04, 2019 3:42 pm

megaohm wrote:Doable or no?
Doable
If yes, what is the poper way to apply AC to these two?
Connect the Live and Neutral in parallel.
Any details or gothchas I'm missing?
Make sure that the Earth is only connected to one place, preferably the junction between the two 30V outputs.

Make sure that the sense outputs are connected to their adjacent pins.

60V is considered a hazardous voltage

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megaohm
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Post by megaohm » Tue Sep 10, 2019 8:03 pm

Late reply but wanted to say
THANKS!!!!

I hooked these up over the weekend as instructed and it works great.
Now...if only I could say the same for the SCAMP modules I have since tested.
www.MegaOhmAudio.com

Will work for pistachios

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