Power Supplies, multiple output, negative included

[skimask]

I got another project, searched Digikey and Mouser, nothing turned up yet...

I need a multiple output power supply to test some aircraft equipment. Needs:
-28v @ about an amp
-6v @ less than an amp
+5v @ less than an amp
variable 0-5v, both at less than an amp.

I could easily build one (maybe for use at the house on my own workbench), but trying to get one approved by the FAA (or whoever) using a homebuilt PCB would be practically impossible.
Heck, if I could just find a PSU with -28v out, I could probably build up something to regulate the -6 from that and use a seperate supply for the +5v. That might fly...
Worse comes to worse, I'm going to end up with a 33 cell NiMH pack with taps for the various voltages running to regulators...which wouldn't be so bad, at least it would be halfway portable.

Anyone got any good ideas?
Any bad ones?

[Melanie]

You're losing it ski...

Most good PSU's have floating outputs, so until you link them together they are all independant. Lots of PSU's out there with single, dual and tripple variable outputs. All those outputs are completely independant... nothing to say you've got to strap all the Black terminals together.

So, just connect the Red +ve Terminal of one output to your Common Ground (0v) point and the -ve Terminal then becomes your -ve rail (with respect to the +ve terminal). So, just dial-in 28v and you've got your -28v Supply. Ditto for all your other rail requirements, positive or negative... Black or Red, all depends on which one you connect to 0v.

[Acetronics2]

Hi, Skimask

There are TONS of those supplies ... manufactured in the far east ... you'll find one with a different sticker in the US !!!

http://www.selectronic.fr/article.as...r=80.4677-9999

for the price, just multiply by .7 and you'll get an US $ price ...

in english here : ( with the scheme !!! )


http://www1.produktinfo.conrad.com/c...ins=62&lang=FR

Alain

[skimask]

You're losing it ski...
Most good PSU's have floating outputs, so until you link them together they are all independant.

I had that same DUHHHHH moment this morning at about 3am.
Vout,,,+Vout,,, -Vout, it's all relative...
33v difference between -28 and +5, make a +33v and tap out of that as required, of course the 'ground' at +28v will have to handle ALL of the 'return' current.
No problems now...

Hi, Skimask
There are TONS of those supplies ... manufactured in the far east ... you'll find one with a different sticker in the US !!!
Alain

I guess I forgot to mention one key aspect of this 'project'.
I can't use a 'power supply' like we (we as in tinkerers, hobby type folks) think of power supplies.
What I really need is a 'brick' or at least an open frame PSU...but, as you can see from the comments above, I got this one licked....I hope...

Thanks for the pointers...

[T.Jackson]

I could easily build one (maybe for use at the house on my own workbench), but trying to get one approved by the FAA (or whoever) using a homebuilt PCB would be practically impossible.

You're an aviation technician Ski?

That sentence has good reasoning (explanation) a long with a conclusion, and implies that you are (at least your readers will think so)

[mackrackit]

Hey Trent
Have you read skimask's public profile, Yep, I would say he is an AV TECH.

[T.Jackson]

Yep, I would say he is an AV TECH.

Gee whiz aye -- that must be a considerably high paying job, I'd also imagine that you'd need to have some serious credentials (especially in America) Unlike a motor vehicle, there's no second chances with an aircraft if a fault occurs due to malpractice on the technician's part (the thing's just going to crash, you can't exactly just pull over to the side of the road) This is my reasoning for saying that it's a high paying job that would require a certain type of person with the appropriate credentials.

[mackrackit]

I have a good friend that is what I call a Harrier mechanic. 20 some years in the Marine Corps.

Yes, he has credentials out the you know what. As far as the type of person to work on these things...Attention to detail, enjoys reading data sheets and manuals, has a protocol for every thing and expects everyone else to also. So much so that he can be a real pain at times but you over look this. They know all to well that there is not a second chance.

The guys and gals that keep these birds in the air for us are are perfectionist, could not be any other way.

[T.Jackson]

The guys and gals that keep these birds in the air for us are are perfectionist, could not be any other way.

Exactly. Someone doesn't fit the profile for it.