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Posted By: metecakir Great Electrical Power Engineering Forum - 02/17/12 10:51 PM
Hello , I am a newcomer and I want to say hello to you , giving you my blog address so that you can enjoy it!

[color:#3333FF]Great Electrical Articles[/color]
Posted By: Trumpy Re: Great Electrical Power Engineering Forum - 02/18/12 04:08 AM
Hi there and welcome to ECN.
Normally we don't encourage people putting links in here, especially if they are new.
However, seems you aren't actually selling anything and your place is electrically orientated, it's all good. wink
Posted By: pdh Re: Great Electrical Power Engineering Forum - 02/25/12 03:34 AM
I'd like to find one of those transformers with 4 120V windings, at least 50VA per winding. They don't seem to make that line anymore.
Posted By: Tesla Re: Great Electrical Power Engineering Forum - 02/25/12 06:29 AM
pdh...

That WOULD be a weird transformer....

Yet, physics permits it.

Economically, it'd be as valuable as a &^% on a boar hog.

metecakir...

Our own Scott35 already has killer transformer diagrams.

I cannot recommend them too highly.

Cheers.
Posted By: Scott35 Re: Great Electrical Power Engineering Forum - 02/26/12 09:29 AM
Tesla,

Thanks for the kind words, per the Transformer drawings!

pdh,

Does the Transformer with (4) 120V Secondaries have a 240V 1 Phase Primary? Kind of sounds familiar... like something from an old Radio set.

-- Scott (EE)
Posted By: pdh Re: Great Electrical Power Engineering Forum - 03/10/12 05:27 AM
Wire 2 of the 120V windings in series. As long as it has insulation rating to handle the 240V it should be fine.

One use of such a transformer would be to stepping 120V (2 windings in parallel) to 240V center tapped. I'm still looking for one to do this that is integrated with an enclosure where I can put a 6-15R or C13. And I want to keep it small so I can carry it with me.

A very common transformer with 2 120V windings and 2 240V windings (commonly used to step 480 down to 120/240) would not work for me, since my goal is to get a center tapped output (120V or 240V) with a 120V input.
Posted By: LarryC Re: Great Electrical Power Engineering Forum - 03/10/12 10:11 PM
pdh

What power rating are you looking for? I have some 3.5 KVA medical grade isolation transformers. Dual 0-100-120V primaries with dual 0-120V 15A secondaries.

Datasheet MT3759DS

Posted By: pdh Re: Great Electrical Power Engineering Forum - 03/13/12 02:50 AM
I don't need more than 100VA ... light weight so I can carry around with the netbook I power up with it where I need to when the battery runs low. This is so I don't have that 120 Hz vibration feeling on the surface in front of the keyboard around the mousepad due to the fact that the unbalanced power the 120V normally has will be capacitively coupled across the power adapter and raise the voltage level of the DC side by 60 phantom volts relative to ground.

It looks like that catalog does have something I might be able to use, if I can find a suitable enclosure for it to mount a receptacle and either grommet a cord or mount an inlet.
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