[time-nuts] WWVB "repeater" (was: WWV Simulator Programs)

M. Simon msimon6808 at yahoo.com
Mon Jan 6 21:32:34 UTC 2014


May I suggest United Chemi-Con EKZM series capacitors. They are very long life electrolytics.  

Data sheet: http://www.chemi-con.com/components/com_lcatalog/uploaded/8/4/4/79794946651719ba91258a.pdf


They are rated 6,000, 8,000, and 10,000 hours at load (max ripple current) depending on case size. The actual life is longer at lower temperature (below 105C) and lower current. The relationship with current and temperature is non-linear. Mouser carries them: http://www.mouser.com/Search/Refine.aspx?N=1323043&Keyword=ekzm


Reliability

http://www.chemi-con.com/index.php?option=com_content&view=article&id=11&Itemid=17  

Capacitor life
http://www.chemi-con.com/index.php?option=com_content&view=article&id=12&Itemid=19

General page including the above links
Understanding The Aluminum Electrolytic Capacitor

http://www.chemi-con.com/index.php?option=com_content&view=article&id=13&Itemid=5


Simon


====


Date: Fri, 03 Jan 2014 13:25:10 -0700
From: Clint Turner <turner at ussc.com>
To: time-nuts at febo.com
Subject: [time-nuts] WWVB "repeater" (was:  WWV Simulator Programs)
Message-ID: <52C71CA6.10704 at ussc.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Sometime in the late 1990s, a friend of mine who works for a local city 
government asked me if there was something that I could do about some 
WWVB clocks located in a conference room, downtown, on a middle floor of 
an office building amongst computers and fluorescent lights that never 
managed to get the correct time.

Together, we built this:

http://ka7oei.blogspot.com/2013/03/getting-atomic-wwvb-clocks-to-work.html

It's been in operation since it was installed, except for two occasions:

- After a few weeks it quit working so my friend opened the cover of the 
outdoor unit to take a look.  Once the water drained out, it started 
operating again.  (He then drilled a drain hole and sealed everything 
else a bit better.)

- Last year - after somewhat more than a decade of operation - it quit 
working when the electrolytics in the transformer-type "wall wart" that 
powered it dried out and there was several volts of AC riding atop the 
DC output.  A new wall wart was procured and I added a large capacitor 
in the indoor amplifier's box as well.


======




Engineering is the art of making what you want from what you can get at a profit.


More information about the Time-nuts_lists.febo.com mailing list