Sourcing transformers

[mgookin]

I'm finding it to be a challenge sourcing a transformer or transformers.
We've all bought $10 electronics and found a laminated core transformer inside. Why can't I find a $10 transformer?

We have a $9,000 AC Power Source at our test station. It is awesome. It will replicate any power grid on Earth with respect to voltage and frequency.
I started a test about a week ago and it's still running. I got nervous during a thunderstorm (we're in the Everglades) and it survived. We did lose the data but that's ok.
It got me thinking though.
I really don't need to be running this expensive machine for day-to-day functional testing of product or even for most long-term testing. I only need to use it when I need to test to a voltage and/ or frequency we don't get from POCO (we have 2 services, both of which are 120/208 3p Y so there's no 240, 277 or 480).

So I'm thinking some small transformers. The test I'm running now pulls about 10 watts max. I spent >1 hour on digikey and other sites to no avail.

What search terms should I be using to find these? They can be open, cased, anything... Wire or screw terminals, doesn't matter. Chassis mount would be best.

When I google "transformers" and click Images I see kids toys which transform from one toy to another.

Thanks.

 

[mgookin]

I should have added:
I'm looking for 1:2 (120 to 240) first and foremost.
And if I can get one for 120 to 277 I'd pick that up too if it's cheap.

 

[dkidd]

Try

http://www.newark.com/webapp/wcs/st...r=1&showResults=true&aa=true&pf=811980046&vw=

http://www.alliedelec.com/power-products/transformers/

http://www.digikey.com/product-search/en/transformers/power-transformers/786735

 

[mpoulton]

What you're looking for are often called "control transformers" because they are used to provide limited power to control circuits of varying voltages. In addition to the sources above, most standard configurations are available on Amazon and from McMaster-Carr and Grainger.

 

[mgookin]

I ended up at MCI Transformers.
The search phrase is "Chasis Mount Autotransformer"

Thanks.

 

[mpoulton]

I ended up at MCI Transformers.
The search phrase is "Chasis Mount Autotransformer"

Thanks.

An autotransformer may or may not suit your needs, depending on the details. Autotransformers have one single winding (or an equivalent arrangement) and function like a buck/boost transformer. The output is not isolated from the input. If you need to recreate electrical service arrangements from other parts of the world, you may need more control over phase connections and grounding than what an autotransformer can give you. A regular control transformer has two or more isolated windings that you can set up however you want.

 

[mgookin]

An autotransformer may or may not suit your needs, depending on the details. Autotransformers have one single winding (or an equivalent arrangement) and function like a buck/boost transformer. The output is not isolated from the input.

Concur.

If you need to recreate electrical service arrangements from other parts of the world, you may need more control over phase connections and grounding than what an autotransformer can give you.

We do that with the power source. I just can't see running that expensive equipment just to have 240 running 10 watts for a week or a month.

A regular control transformer has two or more isolated windings that you can set up however you want.

Interestingly there are 120-240V US-EU converters on eBay for $9.99 with free shipping. They are rated 100 watts. It seems illogical I can't source a $10 transformer when I could buy that, dissect it and throw away everything except the transformer.

Thanks.