8mm Forum: External 220V/100V Transformer started smoking

This is topic External 220V/100V Transformer started smoking in forum 16mm Forum at 8mm Forum.

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Posted by Pablo Alvarez Roth (Member # 655) on March 29, 2007, 04:29 PM:

Hello Everyone, last night I had a bit of a scare after 20 minutues of projecting on my eiki SL-O the new transformer I had it pluged on started smoking really bad, I mean really bad I thought it would blow up, I quicky unpluged the projector and the transformer (I just hope it didn´t do anything to my projector)

The transformer I has it pluged into was a normal 220V/110V stepdown transformer 100Watts. I think it could not take it since it heated up to quickly.

What trahsformer should I buy for this projector?

Posted by Tassos Laudas (Member # 588) on March 29, 2007, 06:31 PM:

Pablo you simply need a transformer that exceeds the power of the projector itself. Assuming that the projector is rated at about 400 W, the 100 Watts of the transformer you've used are far too insufficient.

Posted by Jean-Marc Toussaint (Member # 270) on March 30, 2007, 01:04 AM:

Pablo, Tassos is right, think of the lamp itself: it will draw 250 watts alone... You really need a bigger boat, er, I mean transformer...

Posted by Lars Pettersson (Member # 762) on March 30, 2007, 03:30 AM:

Jean-Marc!
"You really need a bigger boat" [Big Grin]

Brilliant!

Er... now WHERE did I hear that before?

Amicalement,
Lars

Posted by Pablo Alvarez Roth (Member # 655) on March 30, 2007, 02:15 PM:

Got it, on the back label it say´s total watt 0.43KW so I think that a 500 watt transformer should do the thing.

thanks guys.

Posted by Joerg Polzfusz (Member # 602) on April 02, 2007, 06:22 AM:

Hi,

you might also think about checking the transformer's voltage as well: E.g. most European countries switched from 220V to 230V some years ago, while the USA and Canada switched from 110V to 120V (or was it 115V or 130V?)... anyway: Several friends of mine are still playing around with their Commodore C=64-computers. And the external transformers (designed for 220V) started to give up on nearly all C=64 very soon after the switch to 230V. But since some types transformers are hard to sell you'll still find some "220-only"-transformers in some of the shops... .

Jörg

Posted by David Pannell (Member # 300) on April 02, 2007, 06:58 AM:

Something very strange there Joerg.

Running a 220-volt transformer on 230-volts should have no detrimental effects whatsoever. That's only an increase of 4.5%, which should be well within the tolerance of input for any transformer - in fact, negligible!

Having been involved in transformer design, I can only think that these transformers are underrated for their job as a really cheap 'get out'.

Quite often you get what you pay for, and where electrical items are concerned, my advice is always 'don't do it on the cheap'.

Perhaps it might be an idea to suggest to your friends that they invest in a really good quality transformer, even if the primary is for 220-volts. It should take it in its stride! Honestly.

Best,

Posted by Joerg Polzfusz (Member # 602) on April 02, 2007, 07:58 AM:

quote:
Running a 220-volt transformer on 230-volts should have no detrimental effects whatsoever.

I know. And the transformers used on the Amiga, slide-/film-projectors, model-railroads, ... are still working fine, too!
Nevertheless I know of at least 10 dead C=64-transformers. A friend of mine examined his dead transfromer and said that it was obvioulsy designed for peaks with 230V while the temporarly peaks at 230V can reach 240V. Or short: the transformer was so cheap, that it's hard to belive that it didn't already started to blow at 220V.
In other words: It's best to check the transformer's quality twice before buying a new one. And having a transformer with some "more capacity than needed" wouldn't hurt either.

Jörg

Posted by David Pannell (Member # 300) on April 02, 2007, 09:45 AM:

EXACTLY!! [Big Grin]

Well stated, Joerg.

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