Re: Looking for advise on PC FlowMeter
From: GTD (duh_at_stoopid.net)
Date: 03/17/05
- Next message: R.Spinks: "Re: current sources not adding up"
- Previous message: videoman_at_ccountry.net: "Using a d cell battery to power a digital watch?"
- In reply to: Lord Garth: "Re: Looking for advise on PC FlowMeter"
- Next in thread: Rich Grise: "Re: Looking for advise on PC FlowMeter"
- Messages sorted by: [ date ] [ thread ]
Date: Wed, 16 Mar 2005 16:41:53 -0900
>Nice but you will have to have a way to multiply the paddle wheel pulses
>into the KHz range. Most system fans want about 3500 RPM to prevent
>a 'fan to slow' alarm. I am assuming that one revolution of the fan results
>in one pulse on the tach, you'll have to test that theory. Perhaps a phase
>locked loop (PLL) with a divider in the feedback path will do. Look at
>the spec sheet for a 4046 here:
>http://www.semiconductors.philips.com/acrobat_download/datasheets/HEF4046B_CNV_3.pdf
Thanks for the ideas, much appreciated. I could and probably will set
it up with 3 or 4 magnets, so it'l be that many pulses per rev. It
will have to have at least two just to keep the paddle balanced. The
software I'll be using is very flexible, and the fan speed alarm do
not have to be used.
>
>Don Lancaster has a section in his 'CMOS Cookbook' regarding this device.
>Don's web site is www.tinaja.com
I'll check it out, thanks.
>
>I'm guessing that there is a pump motor in this cooling system, what about
>stealing a tach signal from there?
This won't help me if a line gets plugged, the pump goes ntts, or
something stupid like that. Also, I'm interested in seeing just a
simple drop in flow rate as opposed to waiting for a complete stoppage
if something bites it.
>
>How about a temperature to frequency circuit?
I'd rather not wait for the temp to go up, by then it may be too late.
----------------------------------------------------------------------
You should start drinking prune juice and KY jelly cocktails right now,
that will make things a lot smoother.
-Felatio Love
- Next message: R.Spinks: "Re: current sources not adding up"
- Previous message: videoman_at_ccountry.net: "Using a d cell battery to power a digital watch?"
- In reply to: Lord Garth: "Re: Looking for advise on PC FlowMeter"
- Next in thread: Rich Grise: "Re: Looking for advise on PC FlowMeter"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
