[ARC5] Circuit Help Needed

[Tom Lee]

If the unregulated supply has very poor filtering, then setting the 
average value high indeed helps, as then the worst-case ripple never 
gets close to letting the supply drop out of regulation. That said, 700V 
does seem like overkill. Beefing up the filter capacitor and reducing 
the unregulated voltage to, say, around 500V, would cut dissipation in 
half, which can't be a bad thing (except, maybe, in winter), without 
affecting regulation in any significant way.

I no longer know what the cost of a suitable capacitor would have been 
at the time. Maybe it was high enough to drive the design decision. 
Guess it's time to dig out some old radio mags to see what the cost 
equation might have looked like then.

--Tom

-- 
Prof. Thomas H. Lee
Allen Bldg., CIS-205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu
650-725-3383 (public fax; no confidential information, please)

On 2/10/2017 11:59 PM, WA5CAB--- via ARC5 wrote:
> With respect to the value of the unregulated upstream voltage, 
> although decreasing it does reduce the dissipation in the pass 
> elements, increasing it improves the regulation somewhat.  Most 
> noticable when driving a step functiion load such as a CW transmitter.
>
> Robert Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20170211/e892abc0/attachment-0001.html>