[time-nuts] Using a common power supply among few time standards

[Charles Steinmetz]

Chris wrote:

> How about using the open frame linear supplies like the ones from Power One or Lambda?

I have had very good results with Deltron open-frame linear supplies. 
They have selectable mains voltage and low output noise (1mVrms/5mVp-p). 
  I have used many (i.e., hundreds) of the Model W303E triple-output 
supply.  These have one, 5v/8A section and two sections, each selectable 
between 5v/12v/15v at 0.7A/1.7A/1.5A.  [*NOTE* there is an overall 55W 
output limit, so they will not do all of that at once.]  Each section 
can be adjusted +/- 5%.   These show up regularly on ebay.

As for switchers, I have been satisfied with the performance of 
Integrated Power Designs (IPD) products.  [IPD is a different company 
than Power Designs, who made some of the best lab and bench power 
supplies of the 1960s through 1990s.]  One in particular may be of 
interest to time nuts: the Model SRW-65-4006.  This is a four-output 
supply (5v/5A, 24v/1A, and +/-15v/2A) [*NOTE* again, there is a 65W 
overall limit, so it won't do all of that at once].  It is available 
open-frame or with a chassis and cover.  For installation close to other 
circuitry, and particularly inside a piece of equipment, I strongly 
recommend the model with both chassis and cover (options CH and CO). 
Check ebay and look at distributors.

Assume you will need to post-filter the switcher output, either with L/C 
filters or low noise linear regulators.  Note that I did not say "LDOs". 
  I don't know why, but everyone seems to be stuck on LDOs these days. 
Active regulators (including LDOs) *always* perform better with more 
headroom (up to 4v or so).  The only excuse for designing LDO is if you 
have a gun to your head from a power budget you can't otherwise control. 
  [Here, "LDO" is mostly a matter of how you use the part, not of its 
claimed capabilities -- "LDO" regulators work much better with at least 
4v of headroom.]

Best regards,

Charles