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[Amps] Filament Inrush Control

To: <amps@contesting.com>
Subject: [Amps] Filament Inrush Control
From: dj2001 at mn.rr.com (dj2001@mn.rr.com)
Date: Fri Mar 28 16:58:24 2003
I have watched the HV come up when I turn on the AL-80A, it comes up 
very fast and I find it hard to tell when it is at that point and the 
relay clicks in.
I'll try a dc relay, I think the ac relay on the 115 line (the AL80A 
is wired for 220) maybe comes in too fast.
tnx Phil

73
Dale K9VUJ



>  > The delay isn't really a key parameter. The big current surge is over
>>  within a 3-4 mains cycles. After that, the current slowly ramps down, so
>>  you can short out the series resistor as soon as you like. When the
>>  relay pulls in, there is a second current surge - a step-up in current
>>  to the normal standby level.
>
>When I design from scratch with a typical step-start circuit, I adjust the
>delay on the relay until the reading on the HV meter is 2/3 the way up
>to normal value. By this time, all surges are over, and the filter cap(s)
>are almost charged. This assures that the step-start is not operating too
>fast, nor is it hanging in too long, heating up the resistor(s) in series
>with the a.c. mains. This saves a lot of set-up time if the power source
>for the relay comes from other than the transformer being step-started.
>
>Just one of many ways to end up with an effective circuit.
>
>(((73)))
>Phil, K5PC
>
>
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