Isolation transformer and safety

[mw52563]

Hi,
Being a complete novice, yesterday I managed to blow a fuse on the circuit board for a treadmill. I've been researching it a lot more and I've come across isolation transformers that I wasn't aware of previously. I don't plan on doing anymore electronic work in the near future. But I'd still like to have something available safety wise on the off chance. I cant find anything on eBay so I was thinking, just for circuit testing would these two transformers connected back to back work?

https://cpc.farnell.com/multicomp/mcta120-12/120va-toroidal-2x12v/dp/FF01560

I also have a 240v to 110v transformer that I used to use on a building site. Would using a 110 to 240 plug on it have the same effect?
**broken link removed**

Thanks for any help
Mike

 

[rjenkinsgb]

The transformers would not work well, they would be rather inefficient.

The cable passes 240V direct to the 110V connector - it's for test equipment, not for powering things!

CPC do sell a range of 230V > 230V safety isolating transformers:

https://cpc.farnell.com/c/electronic-electrical-components/transformers/isolation-transformers?secondary-voltages=230v

The power rating in VA should be at least 50% higher than the watts rating of anything you may connect, and for a motor driven device may need to be several times higher.

Edit:
There is a 200VA one on ebay at a reasonable price:
**broken link removed**

 

[schmitt trigger]

Indeed, the unit is clearly described as an adaptor.

This is similar to the travel adaptors you find in airports to connect devices in different countries. These adaptors assume that your device has an universal power input, from 100 to 240 V, 50/60 Hz.

Otherwise your device will fail. Ask me how I know.

 

[mw52563]

Ok thanks
I'll go for the one on eBay then

 

[mw52563]

Hi
There's a few on eBay that are isolation transformers that also convert to 110v would these work?

 

[Nigel Goodwin]

An isolation transformer only offers a very minor increase in safety, and ONLY if you know exactly why that is, and understand exactly what you're doing.

In some respects it can be MORE dangerous for those who don't understand it, as it gives them a false sense of security, only offering any advantage at all for a small number of specific situations.

In my previous career as a TV Bench Engineer I built them in the service benches (twice, in two different locations), as there 'may' have been a legal requirement for them - it's a bit of a vague area, so we did it anyway.

Personally, at home, I once borrowed THREE (for a specific purpose), and gave them back afterwards - even though I was free to keep them, and they were nice 1000W versions. I later turned them down again, as well as a number of 500W ones.

Where I work now we don't have any, and have no intention of getting any.

My point is, if you have to ask, and don't know EXACTLY what they do, and how they MIGHT help, you probably shouldn't be playing with them.

Incidentally, the various International Manufacturers training facilities I've been on courses at, have never had isolation transformers - and I did once blow a load of parts off a board with a scope

 

[mw52563]

You did or didn't?