What can i do with this?

[crustyshadow]

i have a couple of old power supplies that are begging to be turned into amplifiers.





this transformer is huge....






i have 2 of these that i got for free, one works, one does not. i have a lab grade and a couple of power supplies that have twice the current output of these so i dont need them at all. i dont know if i can use that transformer or not, but at the very least i have 2 perfect chassis that would be ideal to build a couple of 1000 watt mono blocks to run subwoofers with.

any ideas on what i can actually use out of this other than the case?

[jaycee]

1000W is unlikely. 100W more practical.

Transformer, depends on the secondary windings available. Only one large cap which is a shame as you really need two for a symmetric power supply. Bridge rectifiers could be used.

Going by the meters, its high current but relatively low voltage. The secondaries seem to confirm that. I doubt the transformer would be quiet.

[TANDBERGEREN]

Would guess it's a 40VAC secondary on the transformer.
As he seems to have more than one, he should be able to get around 55V rails
if he mount their secondaries in series.

Should be a bit more than 100W.
Benefit: High-current transformers
possible downside: Probably humming transformers.

But there is a cure for the most.

Cabinets? Would be quite a bit difficult to get both transformers and suitable electronics in just one, but what about using the one as PSU and build the electronics alone in the other? Heavu-duty connectors are available. 55V 15A is within reach for a lot of them.

GO FOR IT

[crustyshadow]

hmm, i saw a couple threads on here about transformers that were of similar size, i was hoping this one would be similar. i basically just had these laying around and was hoping i could use parts out of them.

i dont really have much experience building amps and such- my background is in car audio as an installer for 15 years. i have made several circuit boards for non audio related projects so i know i can build an amp, i just need a direction to go in. i understand what you're saying about the cabinets after looking at the prefab cabinets offered on the DIY store, those things are huge. i really do want to build a 1000w RMS into 8 ohms mono block, any suggestions for plans?

[TANDBERGEREN]

1000W amp as "first" project is not recommended.
The complexity in such a project requires some skills wich is better obtained via building some easier amps.
So I cvan unfortunately not recommend any for you.

[Ian Finch]

These are apparently fixed, nominal 12V regulated supplies. I can't see that 40VAC windings would be necessary.
Perhaps only a single 15-18VAC high current winding is available. See the yellow sleeved wires feeding the rectifiers.
The white leads would only power the regulator circuit.

I don't see much useful there apart from a case & heatsink suiting a 100W or so in class AB as suggested.
Perhaps class D suits there if you want to move mountains but then, plate amps are are so cheap and easy for subs.

[5daudio]

astrons usually have 19-21v on the reservoir cap depending on mains voltage in your area

good luck
bob

[jaycee]

Also, forget this 1000W thing. There are *no car amps* that output 1000W RMS despite any manufacturers claims. It is simply not possible from a car battery/alternator.

There is only one application that needs this sort of power, and that is sound reinforcement at concerts. Those amps are usually class G/H or class D and have to run from high-current power outlets - not your typical 13A wall socket. They are large, typically 19" rack mount gear, and require forced air cooling.

For domestic use, with a good pair of speakers, 100W RMS into 8 ohms will be more than enough to have your windows rattling and your floor vibrating

[JMFahey]

As shown, don't think you can use them for much more than car battery chargers or anodizing/electroplating baths.
Voltage too low for anything else.
15V linearly regulated means around 20V DC raw, 25 VDC tops.
Now, *if* you dare to rewind those transformers, you'd have iron for a 400W class amp or thereabouts.
Usually you can pay part of your new copper with the old one, so it does not go to waste.
FWIW I'm doing that now, repairing a 450W powered mixer with a nicked secondary, a drill bit tip went through it (don't ask )

Or sell them for a good price to VHF rig guys, they *love* 13.8V 40A PSUs for their base rigs, and buy whatever you need with the cash.

[TANDBERGEREN]

If You are not to use those instruments, I'd like to negotiate with You, better than if you are to throw them away.