[time-nuts] Z3801A Power Modules -- was time-nuts Digest, Vol 77, Issue 4

[GandalfG8 at aol.com]

In a message dated 03/12/2010 01:11:02 GMT Standard Time, jreed123 at cox.net  
writes:

An  curious thing
is that there are 2 DC to DC converters the main power  converter is 24
volts in and +12, -12, and 5 volts out and the input and  output
voltage is plainly marked on the side of the converter.  The  power
supply supplied with the unit is 24 volts DC and the that converter  is
working fine.  The second DC to DC converter is labeled  UMR-5/4000-D48
which according to the data sheets that I found is a 48 volt  DC in and
a 5 volt DC at 4 amps out unit.  I dont understand why the 2  DC to DC
converters would have a different input voltage with only the 1  power
supply  If anyone has any thoughts about this I would like to  hear
about them.
--------------------
Hi Jerry
 
I've just checked inside a 48 volt Z3801A, actually marked as 38 to 60  
volts, and that contains a Lucent CW025ACL-M module, marked as 36 to 75 volt  
input, and UWR-5/4000-D48, which I'm guessing is what you intended to write  
rather than UMR......
 
When I checked the data sheet for the UWR-5/4800-D48 I found  that although 
the nominal voltage is quoted at 48 volts it's specified  to work from 18 
to 72 volts.
 
 
The DC input for your Z3801A should be indicated on the back, either  19.5 
to 30 volts, nominal 24, or 38 to 60 volts, nominal 48.

 
Since it would seem that the UWR-5/4000-D48 is a suitable module for both  
versions of the Z3801A, and given that your other module is specified at 24  
volts I would say your Z3801A is indeed a 24 volt unit and the supplied  
power supply is correct.
 
There is additional circuitry for the outer oven PSU so it shouldn't be  
assumed that the UWR-5/4000-D48 itself is faulty without checking its actual  
output.
 
I have descriptions and schematics for the oven control circuit etc which I 
 can email direct but you'll also find them here on Didier's site.....
 
_http://www.ko4bb.com/cgi-bin/manuals.pl?dir=05%29_GPS_Timing_ 
(http://www.ko4bb.com/cgi-bin/manuals.pl?dir=05)_GPS_Timing) 
 
regards
 
Nigel
GM8PZR