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Topic: Solid-state anemometer (Read 9847 times) previous topic - next topic

AWOL

A number of years ago (probably at least seven), one of the American pro electronics magazines published a reader's circuit for a zero-moving parts anemometer.
From memory, it used three transistors on the apexes of an equilateral triangle, with a fourth reference device in the centre.

Does anyone have a link to this or a similar article, please?
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

Grumpy_Mike

Quote
it used three transistors on the apexes of an equilateral triangle,


I think those would be ultrasonic transducers. By measuring the flight time (in both directions) you can calculate the wind vector. There was a thread about this here a few weeks ago but I don't know if it ever amounted to anything.

AWOL

No, they were not ultrasonic - it had zero moving parts.
Could have been temperature sensors (something like a TO92 can), but I thought they were fairly ordinary transistors.
I'm guessing it was like a hot wire anemometer.

I really wish I'd photocopied the article.  :(
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

kg4wsv

I remember a similar article from years ago (the 50s maybe) reposted to some web site, about a couple of kids who used vacuum tube circuits to build an anemometer.  Had something to to with temperature measurements and cooling effects of the wind.

As best I recall it wasn't terribly accurate, but pretty neat all the same.

-j


AWOL

#4
Apr 15, 2009, 05:09 pm Last Edit: Apr 15, 2009, 10:05 pm by AWOL Reason: 1
Hot wire anemometers were good enough for the early NASA Mars probes, IIRC.
[googles] Still are, it seems.

The article I saw would have been late 90's / early 00's, and indicated direction (I think) as well as speed.
I forget, but I guess this implies some form of physical shielding of the sensors.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

blalor

Not to be pedantic, but I googled for "solid state anemometer" and found this: http://www.accessmylibrary.com/coms2/summary_0286-9311675_ITM
It looks like it might fit the bill...

AWOL

Yes, I googled that one too, but it isn't quite what I remembered.
It's a pity there's no circuit.
I *thought* the one I saw sensed direction as well as speed, and as I said, I distinctly remember the arrangement of the sensors.
I also had a thought that it was in a pro magazine; my impression is Electronics Now is not a magazine I would have had access to at the time.
Just remembered it may have been the one Bob Pease has a column in - off to trawl through "Electronic Design" archives.
Thanks all.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

AWOL

#7
Apr 16, 2009, 01:50 pm Last Edit: Apr 16, 2009, 02:01 pm by AWOL Reason: 1
Woo-hoo!
Got it via the author's name from Electronics Design, but this one was published in EDN.

http://www.edn.com/archives/1997/090197/18di_03.htm

Enjoy.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

blalor

Here's something that builds on the idea, and has a readable schematic: http://electronicdesign.com/Articles/Index.cfm?AD=1&ArticleID=1978, and there's another version by the same author here: http://ww1.microchip.com/downloads/en/AppNotes/91044a.pdf

I'm not able to find that Cyntec se102 thermistor...

anachrocomputer

It seems from that EDN article that the physical arrangement of the three transistors is critical to the operation of the sensor.  Shame that there's no diagram, or even dimensions of the most important part of the design.

AWOL

Agreed.
I'm sure the original printed article had better detail in that respect.
I'm going to try contacting the author directly.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

blalor

Found another link while searching for "thermal anemometer": http://www.fonema.se/anemom/anemom.html

blalor

This might be the mother lode: the Micro Gust Thermal Anemometer.

http://www.gellerlabs.com/MGTA%20kits.htm
and
http://www.nutsvolts.com/index.php?/magazine/article/micro_gust_thermal_anemometer_mgta

It would appear that the LM399 diode is obsolete, and I don't see a replacement. :(

quinezhu

#13
Jul 17, 2010, 12:30 pm Last Edit: Jul 17, 2010, 12:31 pm by quinezhu Reason: 1
http://www.edn.com/archives/1996/031496/06di3.htm
this article is incomplete.  but I found a complete one
http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/37619d1263040717-thermistor-based-airflow-sensor-opamp-help-airflow.pdf

AWOL

Yes, Woodward is the author alright (see reply #7), but although I contacted the college, I never got a reply.
Maybe he's retired.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.
I speak for myself, not Arduino.

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