Neither are needed any longer.
The capacitors were required because the recovery time of old rectifiers was
soo bad, that you could hear the noise generated in any close by amplifier.
This is no longer the case thanks to much improved manufacturing processes
now in use.
The resistors were needed because the junction capacitances were so
different from diode to diode, that simply by voltage divider action the
voltage spread across the diodes could cause some t exceed the PIV rating
(the ones with lower junction capacitances). I remember measuring junction
capacitance spreads of over 10 to one on diodes FROM THE SAME BATCH! It's no
longer the case today.
Alex 4Z5KS
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Vic K2VCO
Sent: Friday, September 13, 2013 7:54 PM
To: amps@contesting.com
Subject: Re: [Amps] Rectifier equilization?
The resistors are definitely not needed. I used capacitors in my recent
project in order to eliminate switching noise which might appear in my
receiver -- I don't know if this was needed, since I didn't try it without
the capacitors first!
They should also provide some protection against transients, although I also
have MOVs in the primary.
On 9/13/2013 9:28 AM, Hardy Landskov wrote:
> I have just rejoined the amp list after a few years and am wondering
> if the diode equalization question was ever resolved. I am building a
> new bridge HV PS and it uses
> 12 diodes per leg. Rich Measures says using a .01 & 470K across each
> diode is no longer needed due to improvements in semiconductor manf.
> processes. I have 100 1N5408's that came off the same reel so I feel
> they should be matched fairly close. I would like to hear a few
> opinions. Thanks 73 Hardy N7RT
> _______________________________________________ Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
>
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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