My New ISO Transformer

rikitheshadow

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No, this thread is not about Decepticons or Autobots, but the new Isolation transformer I bought to fix up my Taito cabinet.

This ISO is a little different then the one that is wired in my Sunset Riders cabinet and that is why I'm asking. I'm not saying its difficult, its just got an iffy reading on my multimeter.

So this is what is labeled on the ISO....
Primary 120VAC 60HZ (Bottom Coil)
Secondary 120VAC 100VA (Top Coil)

I wired it like.....and what readings I got.......
Primary - AC Line Voltage 124VAC
Secondary - Cabinet Inards 132VAC (without a Load)

Isn't that a little too high for the cabinet's monitor?

I tried wiring it backwards.....and these are the readings
Primary - Cabinet Inards 115VAC (without a Load)
Secondary - AC Line Voltage 124VAC

Please advise!?

This is where I got it from http://www.twistedquarter.com/index.php?main_page=product_info&cPath=13_40&products_id=70
 
Some meters have a hard time giving accurate AC readings... also, measuring a transformer without a load is pretty much a crap shoot as to what you're going to get. If you're really worried about hooking a monitor up, try powering a light bulb, and see what you get for voltage.

An isolation transformer is supposed to be a 1:1, so in theory it shouldn't matter how it's hooked up. But there is no guarantee that the transformer is going to be perfect. Also, it's possible they put a couple more windings in the secondary, to compensate for the inevitable losses in the transformer.

The AC line reading seems odd though - what do you get if you put the meter probes straight into the wall socket? Line voltage around here is usually around 117v. 124v is a bit high. If your line voltage is 124v, then expect a slightly higher than usual output voltage.

-Ian
 
I agree with RetroHacker....put a load on it. Also, 132VAC isn't going to hurt a monitor. IU'd hoook my monitor straight up the that. In my experience, ISO transformers always seem to "up" the voltage a couple volts.

And speaking of wall plug voltages......124VAC doesn't surprise. The walls of my shop output 136VAC!

Edward
 
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