Date: Fri, 27 Sep 2013 03:13:19 -0700
From: Bill Turner <dezrat1242@yahoo.com>
To: Amps <amps@contesting.com>
Subject: Re: [Amps] ?Direct rectification of AC mains to drive the
amp,
>
>Yes all that you mention below is correct Jim. That's why I commented in an
>earlier post that an individual QRO amp builder would get away with doing
>this questionable 3 kW power supply realization technique, but no commercial
>SS amp manufacture would be able to do this due to the electrical codes in
>respect of EU power factor rules and product compliance certification.
REPLY:
Power factor correction is an area I am a bit hazy on. Could someone explain
why the power factor would be different between a direct-rectified PS and a
transformer-isolated one? Either one charges the capacitors with a series of
pulses. What's the difference in power factor?
73, Bill W6WRT
## There is NO difference in PF between direct rectified and a xfmr! It’s
virtually
impossible to try and implement PF correction with either scheme...esp with
ssb-cw
PF is typ .85 to .90 with a high C filter..with or without Xfmr.
## PF correction is done all the time with the newer style switching supplies.
Then you
end up with unity PF at all phase angles. The typ switcher will also operate
on anything
from 170-325 vac on its input....and from 40-70 hz. Telcos and cell sites
have switched over
en masse to the new style switchers. 3.3 kw each in the typ 52 vdc @ 63A
unit....with 6 in
a 25 inch wide rack. They are only aprx 7 inch tall X 14 inch deep. with a
huge load on em,
they are not even luke warm. We literally brought in truck loads of em 2-3
years ago. Zero
failures...and they are on 24-7-365. At $475.00 each.... they are a bargain
for what you get.
Apparently they can also be strung in series, but I have not verified this.
## Still, I would not get wound up about PF correction with any ham gear...
nor V regulation
Jim VE7RF
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|