What is the purpose of this transformer? (Pic)

Jez · 24 Feb 2013 at 11:24

http://dl.dropbox.com/u/27289822/transformer.jpg

What is the purpose of this transformer?

For context, this is inside an illuminated heated bathroom mirror, the transformer is fed via a normal 230v feed from the mains, and outputs to a 230v shaver socket mounted on the side of the mirror housing.

So it receives 230v, and outputs 230v?

Reason i ask, it buzzes like hell, can i just loop it out? I dont see what it is actually doing.

What gives? :confused:

tres · 24 Feb 2013 at 11:28

Uh, why did that jpg just load from the right to left. That was strange.

Malt_Vinegar · 24 Feb 2013 at 11:29

I think its to limit the current?
I say leave well alone!

yhack · 24 Feb 2013 at 11:29

tres said:
Uh, why did that jpg just load from the right to left. That was strange.

Also, for transforming.

dan^uk · 24 Feb 2013 at 11:32

is there a 110v/230v switch?

Cosimo · 24 Feb 2013 at 11:33

Looks like current reduction.

Jez · 24 Feb 2013 at 11:34

dan^uk said:
is there a 110v/230v switch?

No switch, shaver socket is 230v only. The black thing on the right is the shaver socket itself, just fed via the two blue feeds from the transformer secondary.

DampDog · 24 Feb 2013 at 11:34

It looks like an isolating transformer.

http://en.wikipedia.org/wiki/Isolation_transformer

Jez · 24 Feb 2013 at 11:35

Malt_Vinegar said:
I think its to limit the current?
I say leave well alone!

Cosimo said:
Looks like current reduction.

So we think its just as a current limiter in case a faulty device should be plugged into the shaver socket?

Malt_Vinegar · 24 Feb 2013 at 11:36

Think about where you use a bathroom mirror...
Usually right over a sink.
A current limiter is a sensible idea.

Jez · 24 Feb 2013 at 11:37

Malt_Vinegar said:
Think about where you use a bathroom mirror...
Usually right over a sink.
A current limiter is a sensible idea.

Hmm, it is right above a sink

Perhaps given the isolation transformer link above this is also part of the IP rating of the mirror?

Efour · 24 Feb 2013 at 11:37

0.04A

Jez · 24 Feb 2013 at 11:43

OK. All makes sense, very useful thread for me, thanks

ganesh · 24 Feb 2013 at 11:46

Anyone else here click on the thread hoping to see robots?

Jokester · 24 Feb 2013 at 11:49

Jez said:
Hmm, it is right above a sink

Perhaps given the isolation transformer link above this is also part of the IP rating of the mirror?

IP rating is just a measure of how dust/water tight something is, so the transformer won't have anything to do with it.

Jez · 24 Feb 2013 at 11:52

Jokester said:
IP rating is just a measure of how dust/water tight something is, so the transformer won't have anything to do with it.

The socket is exposed though?

IP aside i can see the safety aspect. I wont just loop it out as i guess in theory that would create an unswitched 6A socket right above the sink.

Jokester · 24 Feb 2013 at 11:56

Jez said:
The socket is exposed though?

IP aside i can see the safety aspect. I wont just loop it out as i guess in theory that would create an unswitched 6A socket right above the sink.

Yeah, IP 44 will be the rating of the mirror unit itself I'm guessing, is the socket inside the unit?

http://en.wikipedia.org/wiki/Ingress_protection

Jez · 24 Feb 2013 at 11:59

The socket is mounted to the side of the unit, exposed on the outer edge to allow things to be plugged into it. You can see the socket to the right hand side, it is the black rubber covered device.

neodude · 24 Feb 2013 at 12:03

It's an isolation transformer. It isolates the output circuit from the input.

Because the output voltage is not referenced to Earth or Chassis Ground theoretically this means that you cant get an electric shock by grounding one of the outputs, which is how you would usually get a shock. The only way you would get a shock is by shorting both output terminals of the secondary coil.

Also as stated above there is the current limiting effect. Being shocked by a secondary coil that can only provide 500mA is better than being shocked by a mains circuit that can provide 5A.

Jokester · 24 Feb 2013 at 12:03

Jez said:
The socket is mounted to the side of the unit, exposed on the outer edge to allow things to be plugged into it. You can see the socket to the right hand side, it is the black rubber covered device.

Ah ok, the rubber will be to maintain the enclosures rating, not entirely sure how that relates to the actual socket though, as it won't be splash proof!