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Rectify ac input?
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From: Thomas McGahee [SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent: Sunday, March 01, 1998 4:37 AM
To: Tesla List
Subject: Re: Rectify ac input?
> From: FutureT [SMTP:FutureT-at-aol-dot-com]
> Sent: Friday, February 27, 1998 11:38 AM
> To: tesla-at-stic-dot-net
> Subject: Re: Rectify ac input?
>
> In a message dated 98-02-26 23:57:48 EST, you write:
>
> <<
> > John; Your suggestion reminds me of an idea:
>
> > I have often wondered, and want to try, rectifying the ac
> > input to the transformer primary with a full wave bridge. You'ld still
> > get 120 pps, (60 hz x 2), but they would be all positive, (or negative).
>
> > I'm not sure the transformer characteristics would be to happy about it
> > as you'ld basically be feeding the primary unfiltered dc. Current might
> > go through the roof.
>
> > Anybody have any experience with this idea, or should I screw pennys
> > in behind my fuses first? ;-)
>
> > Daniel Hess
> >>
>
> Daniel,
>
> I'm not sure how the tranny would react either. Another interesting
> approach would be to try using half wave rectification into the tranny,
> for 60 BPS, using a 120BPS type rotary.
>
> John Freau
Daniel & John,
Feeding a rectified voltage into the primary *will* result in *BOTH*
polarities being produced. The output is assymetrical, but clearly
contains BOTH polarities. The further removed the input is from a
pure sine wave, the greater this assymetry. Keep in mind that the
polarity of the output is not a function of the polarity of the input,
but rather the direction of the slope of the input. In any wave that goes
up and then down, you will have both a positive and then a negative slope.
Don't confuse the sign of the slope with the polarity of the input... they
are two totally different things.
Any DC bias present will go towards DC magnetizing the core. Put in enough
of this DC bias and the core will saturate and output will drop.
There is no way to get DC out of a single standard transformer. You have to
rectify
it AFTER it comes out of the transformer.
A simple experiment with an oscilloscope will demonstrate this.
Hope this helps.
Fr. Tom McGahee