DIY Anemometer

[willib]

I started with a pc powersupply fan (pcf or ppf ), one with ball bearings , cut the stator/ armature off and it spins as free as the wind.

did a little rewireing , very little .

and connected it to my meter reading frequency , and got the graphs shown below.

each graph is later in time than the one before it.

cool huh?

[willib]

anemometer

crap could someone fix the spelling please

[commanda]

I take it you have one of those multimeters with the serial RS232 pc connection?

I've got one of them. Wonder if anyone has any Linux software for it so I can actually use it some day?

Amanda

[willib]

yeah its just a rat shack ,but i like it

[Flux]

You shouldn't let it loose with your amoebas, it probably mated with them.

Flux

[willib]

cheerio ole chap

pass me a tea if ya would

thanks so much ..

[tecker]

Oh You take the dequency of the fan hall with your neter compare the out put with a working annomomer  and then throw the annomomer in the  ebay.

[TomW]

(blank)

[TomW]

Commanda;

Google up "zmeter" its pretty fair and I think its on Sourceforge.

Ibedonc hacked up a version for me.

Cheers.

TomW

[TomW]

http://sourceforge.net/projects/zmeter/

[commanda]

Tah, I'll check it out.

Amanda

[willib]

the fan circuitry is made for 12V , but if i put in 5v or so power i get a 5v squarewave out. nice for digital work..

and the fan consumes less than 5mA at 4.5 volts

removing the armature is key to  success

i used a dremmel to cut the armature off , being careful not to cut too deep into the bearing mount.

[willib]

yes i use the hall switch in the fan and the magnet , so the output is two changes in digital per revolution.

say it starts out low...

it will go high , then low ... then high and back low in one revolution

[willib]

at 80 hz i calculate it was spinning at 2400 rpm , not bad ..

[willib]

ok i got the program on a laptop now,

and i am powering it with a 12V battery , should be good to take out for a ride , and calibrate it with the cars spedometer

its an old micron go book with an external battery as the "only" battery..

funny thing i had to fool the external battery into thinking i was using the cells included ..

when in fact i cut the negative and put in a jack for 12V

it had something to do with the equilization of the six batteries that were in there..

anyway i soldered three 10K resistors to the tabs between cells and it works now..

this Micron is a power hungry beast

[willib]

a pipe really..

[dinges]

It's a nice experiment, but whether it'd make a really suitable anemometer I have doubts of.

Like a windgenerator your anemometer would need a tail to keep it directed straight in the wind (or you'd have to manually do that).

The 'eggcup' anemometer doesn't have that requirement. In effect, it's a VAWT, whereas your anemometer is a HAWT...

A while ago I found the cup for an anemometer. Mated it to a small DC motor, which gives plenty of voltage at low RPMs to use a small analog display. I still need to calibrate it though. What I like most about such a DC motor and analog display: it doesn't require external power. The wind provides the power for the readout. Can't get more 'RE' than that.

http://www.anotherpower.com/gallery/dinges/anemometer_resized

Yours is a nice experiment though.

[willib]

Well peter i went out tonight and took some frequency measurements vs MPH of my car.

i did two runs for each mph , one one way , one the other way , this is what i came up with

[willib]

i had to beef up the gauge mount ,so i started with an arbor(sp) , like the one i sent ghurd

i filed the end of the stick so it fit inside the arbor , used a large screw to hold it on ,right down the center of the stick, then i put a small HD platten on top of the arbor.

drilled and tapped two 4-40 screw threads , used two "washers" and mounted the disk, this made a nice platform to mount the wind gauge

then i just used some steel wire , and put it through the "fan" mounts and twisted it closed

it would take more than a gale wind to knock the gauge off the stick

in this photo i got carried away with the hot glue ( to hold the wires in place),but they havnt come off yet so i suppose its ok

[willib]

did ya get a fan open yet?

if anyone was gonna try what i did it would be you

to get the signal out of the fan , i connected a wire to the drain of one of the tiny fets on the circuit board.

if you put the hall switch near an alternating magnetic field ,you can scope out the signal pretty easily , then just apply 5V power and the signal is a 5V square wave out..