[Elecraft] DC Filter Choke on low voltage power supplies

[Ron D'Eau Claire]

Isn't that why such filtering is usually done by "humungous" filter
capacitors? 

That would be my first choice to investigate. 

73, Ron AC7AC

-----Original Message-----
Ed,

Using a large filter choke in a relatively low voltage supply is 
difficult because of the voltage drop across the choke - and that 
voltage drop will change with current draw changes - so instead of 
improving the regulation, it will actually worsen.  The problem is in 
the size wire used to wind the choke.  In other words, a 25 volt drop at 
3000 volts is a drop in the bucket, but even a 10 volt drop at 50 volts 
is likely to be too much.

73,
Don W3FPR

On 2/5/2012 12:54 PM, Edward R. Cole wrote:
> Recent discussion of use of a filter choke with a battery powered K3
> prompts my question in another application.  I have a 50vdc 50amp
> switching PS which will power a 1100w sspa.  Output filtering may be
> needed to suppress switching impulses on the 50vdc output.  I have a
> large filter choke that was used in a 3000v PS which is probably at
> least 5-8Hy.  Do I need a bleeder resistor across it for protecting
> circuits when powering off the switching PS?  Or is using the large
> filter choke not a good idea at all.  What size filter chokes would
> be recommended?  The 50v PS is a HP PS intended for telephone industry
(51v).
>