Hello, while I was looking for some transformers for a PSU build I stumbled upon "lighting transformers" which were fairly cheap, most likely because they are mass produced. To me they look like standard torrid transformers. On label it says "intended for use in halogen lighting only." Is it because they have thermal switch built in?
Specs:
250W
220V/11.5V 50Hz

 

Hello, while I was looking for some transformers for a PSU build I stumbled upon "lighting transformers" which were fairly cheap, most likely because they are mass produced. To me they look like standard torrid transformers. On label it says "intended for use in halogen lighting only." Is it because they have thermal switch built in?
Specs:
250W
220V/11.5V 50Hz

Take another photo with the electrical ratings showing, please.

 

This one has more power but the rest is the same. Spec. for 250w
Weight:2.6kg
Height:48mm
Radius:127mm
Eff:95%

 

I have no experience with them...but my guess is that it'll make a fine high-efficiency, low-noise step-down transformer.

 

The nice thing about Toroidal's is they are easy to add over-winds or different secondaries as needed, usually about 1.5 to 2 turns/V.
Max.

 

On label it says "intended for use in halogen lighting only.

Beware language barriers! If 'halogen lighting' indeed refers to 'incandescent's (as one would expect) then all's well and good (i.e. I agree with @joeyd999 {Post #4}) -- On the other hand should said devices be designed as ballasts for metal halide lamps, you may expect them to be current limited (via leakage inductance), to operate at rather high OC EMFs and, perhaps, be wired/wound as 'auto-transformers'...

Best regards and good luck!
HP

 

Beware language barriers! If 'halogen lighting' indeed refers to 'incandescent's (as one would expect) then all's well and good (i.e. I agree with @joeyd999 {Post #4}) -- On the other hand should said devices be designed as ballasts for metal halide lamps, you may expect them to be current limited (via leakage inductance), to operate at rather high OC EMFs and, perhaps, be wired/wound as 'auto-transformers'...

Best regards and good luck!
HP

Its often referred to as; "low voltage lighting" - so an auto-transformer could potentially be a contradiction in terms.

Toroids probably don't like large voltage transients - so large inductive loads that produce a big fat spark when you break the current, could make you wish you'd included a primary fuse.

 

Its often referred to as; "low voltage lighting" - so an auto-transformer could potentially be a contradiction in terms.

I agree assuming the intended lamps are indeed incandescents (which, based upon labeling, etc. seems to be the case) -- as opposed to HIDs

Toroids probably don't like large voltage transients

I'll take your word for it - but inasmuch as the 'why of it' escapes me - please explain?

Best regards
HP

 

I found the manufactures datasheets. It says that transformer has a thermal switch on the primary winding.

 

Unfortunately in some instances it is a thermal type fuse and if buried without the ends exposed, it renders the Tfmr useless if and when it blows, if one is lucky the the ends ARE exposed and can be shunted out.
Max.

 

Unfortunately in some instances it is a thermal type fuse and if buried without the ends exposed, it renders the Tfmr useless

À la a perfectly good refrigeration compressor but for a 'stuck' internal OCP interrupter

Best regards
HP

 

I agree assuming the intended lamps are indeed incandescents (which, based upon labeling, etc. seems to be the case) -- as opposed to HIDs


I'll take your word for it - but inasmuch as the 'why of it' escapes me - please explain?

Best regards
HP

AFAICR: They have less turns per volt than a conventional transformer - therefore; greater voltage stress on the insulation.

 

Simple to find out, a 10 turn overwind would tell, the ones I use are usually as post #5.
Max.