PSN-L Email List Message

Subject: Re: Etc.
From: twleiper@........
Date: Sat, 22 Jan 2000 15:39:17 -0500

On Sat, 22 Jan 2000 10:47:08 -0800 Karl Cunningham 
>At 06:29 PM 1/21/2000 -0500, you wrote:
>>All one has to do is pass a sample of that error voltage through a 
>>pass filter (only dynamic elements with a period LESS than say 300
>>seconds are measured) and on to the signal processing circuittry.
>>After one or two integrations (this always seems to kick up a few
>>postings...let's see.  The first integration of acceleration 
>>would give velocity and then integrating velocity gives
>>displacement...I think.  But there again, is the high pass filter 
>>actually the first integration? I think so, so the >signal at 
>>that point would be velocity. See what I mean? ).
>I guess I'll have to start going to those meetings again... Poster's
>Anonymous.  I thought I was strong and could resist posting a reply 
>about integration.  But alas, I've succumbed to temptation...

Typical complex discussion follows focussing on the difficulties of 300
sec to .2 sec
period signal processing...

Actually the 300 sec high pass was suggested as a simple way to eliminate
drift. I am
sure that a 50 sec floor would be just as good. That's why I prefer
direct acceleration detection
(coil and magnet) instead of loop derivative detection.

To be sure, my circuits and component values are almost always SOT
(select on test)
and often don't get off the breadboard for years. But it certainly is
good to know that what
I have found to actually work can also be backed up by the theory...


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Larry Cochrane <cochrane@..............>