Maybe I'm missing something, but this doesn't seem to be doing a whole lot of transformation.
I wonder if it should be 240 VAC in?- or is there a need for a "transformer" with the same output as input?
My guess is that it is one of these...
Could be, but then I'd have thought a keyword on the page would be isolation.... Next time I'm at that shop I'll ask.
Isolation transformer for use with 24Vac industrial control gear. 24V supplies are
used in industrial control a lot.
MarkT:
Isolation transformer for use with 24Vac industrial control gear. 24V supplies are
used in industrial control a lot.
Righto.... still wondering why the word isolation doesn't feature on their page, but thanks guys.
JimboZA:
MarkT:
Isolation transformer for use with 24Vac industrial control gear. 24V supplies are
used in industrial control a lot.Righto.... still wondering why the word isolation doesn't feature on their page, but thanks guys.
I searched for isolation transformer. This did not come up.
mystery not solved.
mystery not solved.
I was at the shop earlier, to pick up an ICL8038, but didn't think the counter hand (envelope passer-over and money taker) would be the right person to engage on that. I'll email their tech support.
JimboZA:
is there a need for a "transformer" with the same output as input?
Yes, they're quite common.
It's the "optoisolator" of the analogue world.
Isolation transformers as such are most commonly used to isolate supplies for mains powered equipment.
I suspect this device in question is used in certain situations where the installer or repairer really does not care what it is for, but just uses it according to instructions.
All transformers isolate, its the ones that don't change the voltage that get labelled
as isolation.
Well an auto-transformer is simply a tapped inductor really, but yes, I should
have said "most transformers isolate".
There was a day still is when televisions and radios were wired to 120 volt plugs one wire is neutral essentially ground the other was hot 120 volt and when plugged into a non polarized outlet put the metal case of the tv that was suppose to be neutral at a 120 volt dangerous potential and connecting an oscilloscope ground to it would cause a short to gnd and damage the scope and or operator or any 120 volt test equipment. The transformer floats the ground off the mains preventing the short circuit but allowing the 120 v through or 24 in this case
JimboZA:
MarkT:
Isolation transformer for use with 24Vac industrial control gear. 24V supplies are
used in industrial control a lot.Righto.... still wondering why the word isolation doesn't feature on their page, but thanks guys.
it does :
CHASSIS MOUNT ENCAPSULATED ISOLATION TRANSFORMER, EARTHED,
OK
8)
alnath:
JimboZA:
Righto.... still wondering why the word isolation doesn't feature on their page, but thanks guys.it does :
CHASSIS MOUNT ENCAPSULATED ISOLATION TRANSFORMER, EARTHED,
It does now, yes. They fixed the page after I drew it to their attention. Extract from their email to me:
It is an isolation transformer and the web page will be update.
alnath:
OK
8)
Sorry now it's all out of synch.... I deleted my post to which you responded and by the time I reposted, you had re-responded.
Why would you need to isolate 25vac? Is it a dodgy power supply to begin with? Is it likely to fail delivering 120/240v in which case what happens to the 25v isolation transformer?
cjdelphi:
Why would you need to isolate 25vac? Is it a dodgy power supply to begin with? Is it likely to fail delivering 120/240v in which case what happens to the 25v isolation transformer?
Beats me, I just saw it listed and wondered why changing 24VAC to 24VAC (ie doimg nothing) counted as transformitizing in the first place.....
Same number of windings on both sides?.. there will be some power loss as no transformer's perfect.
I'd understand if you created a cheap capacitor fed supply, if the cap failed the transformer would get a full 240vac.. hang on, wouldent you get 110/240vac out if 110/240 went in? Or would it 'isolate' it by melting 
cjdelphi:
Why would you need to isolate 25vac? Is it a dodgy power supply to begin with? Is it likely to fail delivering 120/240v in which case what happens to the 25v isolation transformer?
I'd suspect it has something to do with grounding. I seem to recall it had some connection(!) with air conditioning systems where you have different units (external and internal) which are each mains powered and therefore possibly separately grounded. It would only be for more complex installations with multiple units.