The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
Subject: Re: Automotive EMI
From: Bill Paul
NNTP-Posting-Date: Mon, 23 Sep 2002 19:05:52 CDT
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly
Date: Tue, 24 Sep 2002 00:05:52 GMT
Chris Matthaei wrote in
> I've been trying to do some low rate (50samples/sec) data acquisition
> of some sensors on my engine (Ford 5.0). I noticed that as the load on
> the engine increases, I see a large increase in noise in the signal.
> I'm guessing this is due to the spark voltage increasing with load.
> Anyway, I'm wondering how I can clean this up. I was thinking of using
> a simple active low pass filter using a 741. 10Hz would probably be a
> good cutoff. Does anyone think this will help? Any other suggestions?
You should run your ADC as fast as it will go, then average the signals 50
times per second. Everyone elses filtering suggestions seem good as well,
but as long as you are taking one sample, there will always be some
quantization error or noise on the signal. If you can sample at 1mS, and
average 20 samples, you will be in really good shape. Enough so that you
can remove alot of your analog filtering.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup