[time-nuts] newbie question Thunderbolt supply

J. L. Trantham jltran at att.net
Sun Aug 26 02:28:34 UTC 2012

I would recommend a linear regulated supply rather than a 'switching'


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Arthur Dent
Sent: Saturday, August 25, 2012 9:25 PM
To: time-nuts at febo.com
Subject: [time-nuts] newbie question Thunderbolt supply

>I think I remember comments about it being used by the DAC.  Wasn't there 
>some mention of the TBolt working with a dead -12 supply, but only as long
>the DAC output was above 0.

That was the conclusion. Actually the units these Thunderbolts were removed 
from used -7VDC instead of -12VDC. Many Thunderbolts will operate with 
the -12VDC line grounded but it shouldn't be left floating. It wouldn't be a

good idea to run the Thunderbolt without some negative voltage on this line 
and where it's easy to find a triple output supply, why take the chance. The

+12VDC is mainly for the oven  and internal to the OXCO it goes to a 
+5VDC linear regulator for the oscillator circuit so the +12VDC isn't as 
critical as the +5VDC.

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