Dick Hanson wrote:
>
>Mauri....
>I agree with you and Marv. My experiences have been that the regulation,
>whatever type you choose to call it, is better with 1) the big zener, or 2)
>small zener in combo with pass trans. Now, if you can't find or don't have
>access to the 10-50 watt zeners, then I'll be first in line for the 5408's
>or whatever. I'm not much of a theoretician (sp?), but I've built more than
>a few amps.
The TL431 "adjustable zener" with a PNP Darlington pass transistor gives
very good voltage regulation - far better than is actually needed -
AND it's fully adjustable
AND the whole thing costs about $3 in parts.
If you're not familiar with the TL431, it's the voltage stabilizer in
almost every PC power supply ever made.
There's a circuit at (deep breath) http://www.ifwtech.demon.co.uk/g3sek/
boards/triode/triode-3.htm#4CathodeBias
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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