anemometer

[jacub]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

 

[John Fields]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

 

[Fred Bloggs]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

Run a search through Electronic Design or EDN for design ideas by
Woodward- he has several good anemometer designs published. The 3.3V
limitation will have to be handled by boost power supplies on board.

 

[Winfield Hill]

jacub wrote...

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

You won't be able to achieve 3% precision over the whole range.

 

[Fred Bloggs]

jacub wrote...



You won't be able to achieve 3% precision over the whole range.

He wants a digital circuit anyway.

 

[Fred Bloggs]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

This might be more in line with what you're looking for:
http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=1978

 

[jacub]

This might be more in line with what you're looking for:
http://www.elecdesign.com/Articles/Index.cfm?AD=1&ArticleID=1978

I think it's good idea. This seems to be fine also.
http://www.edn.com/archives/1996/031496/06di3.htm

 

[Fred Bloggs]

I think it's good idea. This seems to be fine also.
http://www.edn.com/archives/1996/031496/06di3.htm

There was one he published just after that expanding upon the technique
and improving the accuracy. Note that his circuits consume *lots* of
current too.

 

[jacub]

So this method will be more precision?

 

[jacub]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

Hmm. What do You think about idea with Wheatston bridge and broken bulb.
Voltage from bridge will be passed on ADC converter.

 

[Sjouke Burry]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

At least, make it differential,one wire shielded from the moving air,
the other not,that gives you temperature compensation,and less
dependancy on the type of wire.Feed both wires with a current source,
and measure the voltage difference between them.

Burry.

 

[Jim Thompson]

At least, make it differential,one wire shielded from the moving air,
the other not,that gives you temperature compensation,and less
dependancy on the type of wire.Feed both wires with a current source,
and measure the voltage difference between them.

Burry.

Works with thermistors as well. I did such in my Bachelor's thesis on
blood flow measurement with catheter-mounted thermistors (MIT/Harvard
Med School/Peter Bent Brigham Hospital, 1962).

...Jim Thompson

 

[jacub]

Works with thermistors as well. I did such in my Bachelor's thesis on
blood flow measurement with catheter-mounted thermistors (MIT/Harvard
Med School/Peter Bent Brigham Hospital, 1962).

...Jim Thompson

Have You any example schematic or some materials?

 

[jacub]

At least, make it differential,one wire shielded from the moving air,
the other not,that gives you temperature compensation,and less
dependancy on the type of wire.Feed both wires with a current source,
and measure the voltage difference between them.

Burry.

The best results I should achieve when I'll use a platinum wire, but I
have a problem to get this wire.

 

[John Woodgate]

The best results I should achieve when I'll use a platinum wire, but I
have a problem to get this wire.

Nichrome wire is not costly and is easily obtained. It is durable even
when red hot, as in electric heaters.

The disadvantage of Nichrome is that its resistance varies very much
less with temperature than that of platinum. But you may get enough
variation for your purpose.

 

[Jim Thompson]

Have You any example schematic or some materials?

I've got a schematic, but it's Germanium transistors ;-)

...Jim Thompson

 

[Barry Lennox]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

There was the dual metal ball one that was in the Nov 95 issue of
"Scientific American" A number of folk got good results from these,
and claimed accuracy of a few % and resolution of better than 0.1m/s.
However it operates off 9 volts. DC-DC switcher?

 

[Don Lancaster]

I'm going to build simply hot-wire anemometer. It have to work width
3,3V supply. Precision: 1 meter per second. Full scale: 0m/s to 30m/s.
Have you any idea?

We have two real ones up on eBay.

--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Rich, Under the Affluence]

The best results I should achieve when I'll use a platinum wire, but I
have a problem to get this wire.

IOW, if you could afford platinum wire, you could afford to hire
somebody to tell you how windy it is? ;-D

Cheers!
Rich

 

[Winfield Hill]

Don Lancaster wrote...

We have two real ones up on eBay.

I couldn't find them.