Tweakers' Asylum

Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Return to Tweakers' Asylum


Message Sort: Post Order or Asylum Reverse Threaded

Power Supply

172.56.240.17

Posted on November 7, 2022 at 17:00:18
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
I just dug out my International Rectifier 'reference design' amplifier.

It is an AUDAMP7S and is in FULL BRIDGE mode.....(good for sub amp, no?) 500x1 @8ohms.
125x2 @8ohms would seem to be fine for a number of reasonable speakers....and in a non-critical system. The amp is compact and of reasonable efficiency....

Power supply is listed at +-50v nominal.....with a min/max of 45->60......

On board there are 3 power input terminals....+, - and GRND.....

Now? the question......When the board says 50v....is that peak or whatever? And If I bought a Switcher from the likes of Meanwell......Do they make a compatible PS?
If I went DIY? I'd have to start with a toroid and than calculate for bridge voltage drop, change to whatever voltage the amp needs.....Again. that pesky RMS or whatever question..
Too much is never enough

 

Hide full thread outline!
    ...
RE: Power Supply, posted on November 7, 2022 at 22:28:28
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
Documentation for the amp......which I just found online....
shows a 'test setup' which for power, at least, is a B+ PS from + to G/ And a B- PS from G to -

Would that work for a full-time setup? Get a pair of 50v 5 amp supplies (250 watt....) and wire them just like the reference design test setup?


Too much is never enough

 

RE: Power Supply, posted on November 8, 2022 at 08:54:28
Hornlover
Manufacturer

Posts: 2529
Joined: March 8, 2002
That is DC volts.

 

RE: Power Supply, posted on November 8, 2022 at 12:20:01
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
I understand DC.
But if I get a transformer and bridge.....that start of a linear PS?
Do I get higher AC out or Lower AC out, in order to get 50Vdc for the amp?

And the amp has 3 power terminals.....B+, B- and grnd.......If the docs call for 50 v, is that 50 to ground or 50 between B+ and B-?


Too much is never enough

 

you better make sure, posted on November 8, 2022 at 12:27:30
Story
Audiophile

Posts: 10293
Location: NJ
Joined: December 11, 2000
with a schematic or similar. A 100 volt supply is quite a bit from + to - and a healthy current will give you a really big shock, don't screw with it.



 

RE: you better make sure, posted on November 8, 2022 at 20:48:34
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
Worked with implanters up to 200kv......with 20kv extraction.....

Safety is built into those devices. When you open an outer door......a shorting bar descends and shorts the inner terminal to ground. AND than you install the parallel 'chcken stick'......
All doors are interlocked to when any interior door is opened THAT shuts it off, too, unless intentionally defeated.

so I'm not overly concerned with 'only' 100volts.

BUT? I DO appreciate the concern. I've seen some awful dumb stuff over the years......from a guy working on an RF generator on the floor....and someone DROPPED THEIR Stainless Steel TWEEZERS on the board......reached IN and got them out......and no shock.....
And worse......When you deal with some of this stuff.......Even a 'mere' 480 is deadly. Ask the guy who DROPPED HIS WRENCH across the input of a giant transformer. Sound like a cannon and the wrench vaporized......Stuff like THAT.....
Too much is never enough

 

RE: you better make sure, posted on November 9, 2022 at 07:53:16
Story
Audiophile

Posts: 10293
Location: NJ
Joined: December 11, 2000
sounds like you'll do well. I've managed to zap myself 1 or 2 times. it happens.

I could recommend a supply I bought a time ago, + & - & ground but it was not for hi-fi. I charge car batteries JIC.

Maybe someone else can check me on this suggestion, you can take 2- 50 volt supplies, attach the + of one to the - of the other and that's your middle ground point. Then you'll have the + 50 and - 50 and the ground. I recall years ago having to do this for a similar purpose



 

RE: Power Supply, posted on November 9, 2022 at 08:16:24
Hornlover
Manufacturer

Posts: 2529
Joined: March 8, 2002
The data sheet says +/-50V. So that would be 100V between + and -.

 

RE: you better make sure, posted on November 9, 2022 at 23:23:07
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
That's what a diagram in the manual shows as what works......An expensive approach if buying aftermarket supplies....

Don't think for a second I've NOT gotten zapped.
I got zinged by a Tesla Coil maybe mid-60s or so......A very long spark jumped to ME......

But I'm always careful. I hope. One hand in the pocket, when doing certain things.......
And If I DO NEED to go 'into' a piece of gear? Unplugged for an hour or so prior THAN check any of the big PS caps for residual charge.

Last small project? I re-corded an ancient KENWOOD KA-7100 integrated amp. Upped it from 18ga to 16ga, new straing relief and isolated the drilling so NO CHIPS fell into the map.....Than I checked with a magnet and already had 'sticky' tape near the hole.....I got it ALL.....
Too much is never enough

 

RE: Power Supply, posted on November 12, 2022 at 10:31:10
Ugly
Audiophile

Posts: 2912
Location: Des Moines, WA
Joined: August 22, 2006
A couple of these wired in series would give you plenty of overhead for bridged mode. Their output voltage can be trimmed a few percent higher than nominal too.

 

RE: Power Supply, posted on November 15, 2022 at 14:46:59
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
Very similar in spec and price to a few of the offerings from MeanWell.....

And I'm not worried about a couple volts.....Amp would probably run at 40 volts...
Too much is never enough

 

RE: Power Supply, posted on November 16, 2022 at 10:50:32
Ugly
Audiophile

Posts: 2912
Location: Des Moines, WA
Joined: August 22, 2006
Nothing wrong with Meanwell. They used to have some quality control issues but that was maybe 10 years ago and I never had a problem getting things replaced via warranty. I like CUI because their factory isn't too far from my house. Either way would probably be an equivalent assuming like specs. You may want to shoot for a lowest voltage ripple spec though.

 

Page processed in 0.030 seconds.