[Boatanchors] Dropping Resistor Question

[Mark K3MSB]

Now that’s an interesting suggestion.

 For a 20 to 40V drop at 175 mA,  a few 21V 5W zeners should work nicely
(due in part because I think I have a batch of them…..).

Why zeners in series with each diode?  I would think placing the zeners
after the two diodes are combined would work the same?

 And just to make sure (as I don’t want to zorch anything),  for the
positive LV supply the zener cathode is towards the tranny secondary,  and
for negative bias supply the zener anode is towards the secondary.

I would also think doing this would predicate one using in-rush limiting……

73 Mark K3MSB



On Oct 5, 2017 4:51 PM, "David Stinson" <arc5 at ix.netcom.com> wrote:

>
>
> -----Original Message-----
> From: Jacques Fortin
> Subject: Re: [Boatanchors] Dropping Resistor Question
>
> I once had a "solid stated" supply that gave me 195V at full load when the
> "target" was 175V.
> I just used two 20V, 5W zeners, and everything is fine since.
>
> 73, Jacques, VE2JFE
>
> --------------------
>
> You beat me to it, Jacques.  I was also going to
> recommend Zeners, which will do job well.
> D.S.
>
> ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>