Re: [photo-3d] Beware! - Converting a Fed Projector to 110v

[jack.colbran@xxxxxxxxxxxxx]

Beware! A transformer that steps 110V down to 50V will have secondary
winding insulation designed for only 50v. True there is always a good
margin, but you are suggesting placing more than twice the rated voltage
across that insulation. (110V instead of 50V) Could be risky! If you can't
relax when you're watching your stereo slides, then what's the point?

It would be safer to run a 220V to 110V transformer 'backwards', (apply the
mains to the 110V secondary,) at least you wouldn't stress the winding
insulation, but you will hit another problem. The turns ratio of
transformer is tweaked to give a secondary voltage that's a little higher
in order to allow for losses in the transformer. This tweak will be
operating in reverse for you and cause an output that's a lot less than
you're expecting. It won't be 220V. It will be less, and you might get the
old problem of an orangey light from the lamp, the projector will not
perform properly.

As Ron says, an AC/DC transformer is simply a transformer connected to a
rectifier. If you apply the mains to the output of that rectifier it will
go bang!

There will - without a doubt - be transformers specifically for stepping
110V up to 220V. This is safest. They won't be very commonplace and you
might find the price a bit steep. Then you've only got the problem Gabriel
pointed out - frequency. There are boxes that convert, but you're talking
big bucks! I don't know anything about the FED projector, but it's 50Hz
only, it's worth investigating why. The lamp and it's transformer won't
mind 60Hz instead of 50Hz. The fan motors should be okay from 60Hz, too.
It'll be things like automatic slide changing and motor driven focusing (if
it's fitted) that are a problem. You could perhaps change the lamp
transformer, even use an external one. Not very pretty though. I'll bet the
motors for focusing and slide changing run from the same transformer as the
lamp, but through a rectifier. So a replacement transformer might be all
you need.

See if anyone else has converted a FED to 110v.

Sorry to waffle on, but don't take any risks with the mains!

Good luck
Jack
U.K.








Ron Beck <rbeck@xxxxxxxx> on 17/10/2000 14:49:14

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 Subject: Re: [photo-3d] Converting a Fed Projector to 110v   
                                                              







Gabriel (and all),
Unfortunately, the 220VAC outlet for your stove (and electric dryer) is
really two 110VAC circuits with a common ground.  Your extension cord
would have to combine the two hot lines into a single prong in order to
provide a 220VAC power source.

Here in the states you can buy an adapter to convert european 220VAC to
110VAC.  Isn't there a european equivalent to step up 110 to 220?
Theoretically, any AC transformer that steps down from 110VAC to 50VAC
should be able to provide 220VAC when 110VAC is fed to the 50VAC side.
Just make sure it's an AC/AC transformer and not an AC/DC transformer

Regards,
Ron

P.S. Please check this information with another knowledgable source.
I'm reciting from memory of my electrical engineering power class.
However, I did flunk out of electrical engineering  so I may not be
remembering this quite right! :-)

Gabriel Jacob wrote:
>
> Regarding converting a FED projector to 110VAC, why not leave it
> as is and plug it in the 220VAC stove electrical outlet? No kidding.
> Wouldn't that work? Of course the only problem is you would have
> to watch it in the kitchen (might not be so bad, munching on snacks
> while watching 3-D). Unless of course you get a really long
> extension cord. :-)
>
> Gabriel




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