[time-nuts] float chargers for oscillator backup power
bob at evoria.net
Sun Oct 26 23:42:05 EDT 2014
The little brick says it's happy with 18-36V.
From: Bob Camp <kb8tq at n1k.org>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Sunday, October 26, 2014 10:37 PM
Subject: Re: [time-nuts] float chargers for oscillator backup power
We seem to have drifted a bit.
This started out as a supply for the Z3xxx Lucent GPSDO’s. In those units, you have a 24 volt switcher that is driven off of the battery or linear supply. Since it’s designed as an isolated supply, I doubt the switcher in the GPSDO is looking for a very clean input. The same is true of it’s need for a tightly regulated input. Yes it’s efficiency will vary a bit with input and so will heat in the box. Still, not a real big deal if the voltage drops a volt or so when you go onto backup. The GPS is still running to keep everything lined up.
How fast to you need to re-charge the battery bank? For me, not very fast. To keep the batteries healthy, maybe a bit faster than I would like. Lower charge current is another reason to go with a smaller battery if you can get away with it.
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