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Re: [Amps] Step-Starts

To: amps@contesting.com
Subject: Re: [Amps] Step-Starts
From: Steve Thompson <g8gsq@ic24.net>
Date: Sat, 13 Aug 2005 14:16:08 +0100
List-post: <mailto:amps@contesting.com>

Harold B. Mandel wrote:

> 
> What damage would occur if the step-start period were too long,
> considering that the stepping timer and drive were run by a full
> voltage supply and didn't chatter?
My personal views:

Running against most opinions, I see no problem in having a 'long' soft 
start - where there's going to be insignificant power drawn from the 
supply until after the soft start is over. I won't quote GW4FRX at 
length on this, but I'm happy to be over cautious looking after a big 
transformer - especially where a replacement is either expensive or 
never the right shape or size. For my requirements, 5secs doesn't 
matter.  I use a forced timer rather than something that monitors the 
rising voltage - if there's a fault, the fuse blows when the resistors 
are bypassed.

I have no dual voltage issues, but still use two resistors - why not 
spread the heat and the stress, that's simply good engineering. DP 
relays are hardly rare or expensive.

Steve
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