....it's quite a primary concern!!
The problem with filter capacitors is their relatively large series
inductance-ESL.
Since most diode killers are fast rising transients, of relatively short
duration, most of the transient voltage develops across the ESL and the cap
doesn't help.
In modern TV sets there is a special low ESL film capacitor- about
2uF- connected across the input line, ahead of everything except the fuse.
This is the best protection you can reasonably have. Tackling longer
duration transients with high energy content would require such massive
components that you couldn't afford them, or else, some kind of cutout
circuit to disconnect the power supply from the line during the transient.
This was usually done in military vehicular equipment.
Alex 4Z5KS
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Bill Turner
Sent: Sunday, September 15, 2013 5:49 AM
To: Amps
Subject: Re: [Amps] Combiners for SS amps + cooling issues.
ORIGINAL MESSAGE: (may be snipped)
On Sun, 15 Sep 2013 08:59:59 +0900, Leigh wrote:
>A secondary concern would be decoupling the direct rectification
>circuitry from transients and large amplitude spikes often riding on
>the incoming mains voltage. These spikes would need to be adequately
>suppressed from reaching the FET drains lest there be a risk of breakdown
damage.
>
>Leigh
>VK5KLT
REPLY:
If the bridge rectifier is feeding a large capacitor directly, shouldn't
that be enough protection against transients?
I'm no expert on power line transients so I'll defer to those who are.
73, Bill W6WRT
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