transformer (not the robots)

[greg_slo]

i recently aquired a non functional UPS and found out the something crack on one of the boards which was why the unit was discarded. Besides a nice group of batteries i grabbed two large transformers from the UPS. the lettering on the transformers is kinda cryptic and i tried googling different combinations of these letters to try and find specs...i only found a really vague reference to a DIY amp and a couple "isolation transformer" references (i thought all transformers were isolating...?

i was hoping that some one here could crack the code on these. and then perhaps tell me how useful they would be as parts for mono blocks?

 

[Cherian]

The "E" number is the UL (Underwriters Laboratory) listing number. This is the UL File number for either the transformer or its insulation system. The 180 Class H is the rating for the transformer insulation system. This transformer can run up to 180 degree C without any issues. The 430-7104 I will guess is the part number for the transformer and the A4 could be the rev.

I don’t think you can use them for much other than what they are originally intended for. They may be a step up or step down transformer. Without doing tests no way to be sure Hope this helps.

 

[greg_slo]

i thought all transformers were step or step down...is there another kind?

if they are step up then i should be able to use them for amps (?)

i dont know too much about this and my EE roommate is away this summer for an internship...oh well, it was free and worth a hope

 

[ScottGardner]

Many line level audio output transformers are neither step-up or step-down. They are 600:600 ohm isolation types.

Your transformers are made by Leader Electronics Inc most likely for an APC UPS. These transformers are made specifically for one purpose. They step-down for charging the batteries and when power fails they step it back up. So your voltage is typically going from 120 down to 12 and for a short time from 12 back up to 120.

This is not the type of transformer you would want to use in an amp. A typical 100 watt Class A amp has a voltage swing of about 57 volts peak to peak (at 4 ohm).

 

[MotorToad]

Not that it matters much in audio systems, but there are 1:1 transformers in common use which are called "isolation transformers." When a circuit is connected by transformer the source end isn't directly affected by physical circuit problems in the load end, like trees and squirrels grounding the wiring. The source end still has the current used to fuse the squirrel from its mortal coil, but its impedance to ground doesn't change.

 

[greg_slo]

learn something everyday.

you are correct, scott, they are from an APC UPS. though that batteries packs were 24 volt, not that it matters in the least for what's considered here.

thanks for the info folks.

two more questions. how did you tell where these transformers were from? i typed in all sorts of combo's of the codes from the pic but came up with nothing. and also, does any one know what i could use these for other than back in the UPS (which i stole the batteries from for testing purposes for a golf cart project)? other than massively over kill paper weights that is.

~greg

 

[ScottGardner]

two more questions. how did you tell where these transformers were from?

We haf ways... Actually if you do a Google search for E154515 you get a reference to "Leader Electronics Inc" and the 'LEI' clinches it. Other references point to APC. Most times its better to use just some of the numbers when searching for part datasheets because many of the extra digits denote packaging, build date, special order etc...

... does any one know what i could use these for other than back in the UPS (which i stole the batteries from for testing purposes for a golf cart project)? other than massively over kill paper weights that is.~greg

Depends on how much of a DIY guy you are. Have you got a car stereo? You might be able to build a decent power supply for testing outside your car. If you have massive amplifiers you will need a lot of current at 13.8 volts which would be easy to get out of those trannys. Just a bridge recitifier and a few resistors for voltage drop and conversion to DC then maybe a few caps for ripple smoothing and your ready to go. You may even be able to salvage the parts from the APC.

BUT, BUT, BUT playing with 120 volt AC is very dangerous especially when we're talking about many amps of current. Your life expectancy drops to seconds if you blow it (so to speak).

Probably your best bet is to sell them on eBay as replacements for use in an APC. I think there are similar units selling for about $40 on eBay now.

Have fun...