Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang
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Jason -
I suspect the Sigtomics you are using has a relay to short out whatever
surge protection device they are using once the initial time period has
passed.
Here is one type of NTC carried by Mouser. Essentially they have a cold
resistance and a hot resistance. It's a trade off between the higher
cold resistance to limit the current surge at turn-on, and the hot
resistance which can be significant if you have a large delta I. One
of shortcoming is if the power is interrupted momentarily, there is no
protection because the NTC doesn't have time to cool off. Another is
that they generate considerable heat, and so have to be mounted clear of
temperature sensitive objects.
73, Garey - K4OAH
Atlanta
Drake C-Line Service Manual
<http://www.k4oah.com>
[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] made an utterance to the drakelist gang
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On Thu, 19 Jan 2006, Keith Hamilton wrote:
Has anyone tried the soft-start current limiting boxes sold by Sigtomics
(http://sigtomics.com)? Would that help prolong the life of the on-off
switch as well as the transformer? My AC-4 really "thumps" when I turn
my T-X4C transmitter on. Seems a better solution than a cheap computer
power strip. Or not?
I've got the 600/1000W version for amps. I've used it with my R-4B and
T-4XB plugged into a power strip from the lower wattage outlet on the
sigtomics box - when plugging the sigtomics box into a wall outlet the
R-4B and T-4XB (and AC-4) are silent when coming on... no thump at all.
If I knew what make/model of thermistors were in the sigtomics box I'd buy
a few (they can't cost more than a dollar each) and put them in the power
strips. The voltage does not sag between idle and key down - so despite
my earlier concerns about thermistors and voltage sag it seems to work
quite well.
--
73 Jason N1SU
http://n1su.com/
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