'Analogic' Fan/Volt Monitoration

Hey guys!

Anyone has any clue on how to monitore volts and fan RPMs with a needled multmeter?

My idea is like this:
A PWD fan controller.
A needled multmeter showing RPMs for the 'selected' fan -- I guess a normal swith, like those ones with On/Off, but with three or four positions would do the 'selecting' job(Was thinking of something that would also allow the MB sensor to detect the RPMs. Maybe grounding up the multmeter's GND with the motherboard's fan's GND, and plugging back the white wire on the MB. Just don't know how to get the fan's pulses and make it hold a needle in it's place, like a voltmeter).
Another needled multmeter showing the selected voltages (Again, not affecting MB's sensors. Just don't know how I would get the same voltages as the MB measures with the sensors).
[edit]How could I forget it? Also, another multmeter for the temperatures.[/edit]

The thing is that I don't want to buy an LCD (VFD) because it's too expensive; and I would build one (digital), but I also don't want anything that would depend on a software sending it the informations (and wasting resources that could be used to render games. lol). Besides, I think building a VFD display with it's own sensors from scratch would be too much effort expent on something that wouldn't be worth it.

So, in short: it would have it's own sensors (independent of MB's sensors) and show them on 3 multmeters - one for voltages, one for RPM, one for temps.

By the way, it could use the MB's temperature sensors, it it's not messy soldering around the MB.

-- Just noticed it would look a bit like the 'musketeer'... lol



Anyone seen that before; anyone think it's impossible; or has any idea on how to 'build' it? =))

Well the a fan checks RPMs by pulling the motherboards signal line to ground every 2 rotations. So i guess you could use a PIC microcontroller to count your RPMs and then output to say a LED display (like the kind in alarm clocks).
Here is a 2x20 character LCD for REALY cheap. It has a backlight and everything.
They have Many other LCDs for decent prices at that site. Im planning on buying one of their 4x20 LCD modules. Also LCD smartie uses up almost no resources whatsoever. Using Speedfan and LCD smartie together to display my core temps and rpms on a 2X20 LCD used almost nothing. Also noting that LCD smartie gives me a constant readout of my CPU usage. You will notice nothing. I wish I could help you out on the RPM monitoring. In theory with a 10k resistor from 5v to the signal line of the fan with a small capacitor you should get a voltage fluctuation differance on the capacitor at different RPMs. There is probably a formula to figure such a thing out but I dont know. With a variated voltage one could easily convert it to RMPs with a multimeter if the formula is known. hmmm.


EDIT

as for temps there is a simple program using a PIC that can determine temperatures and output them to an LCD display.

Hum... I don't know, the needled gauges won't get off my mind since I [recently] saw the musketeer... lol

I don't know anything about electronics (only a small idea about 'what a capacitor is for', 'what a resistor is for', 'what a transistor is for' etc); but I think anyone could build small circuits. I have done a small sound amplifier once, with NO knowledge at all -- in fact, I guess I was 12 or something. And that was the only thing I've done with electronic components. lol

Anyway, I'm pretty sure the "wave's" shape sent by the FAN's RPM is squared. If only it was 'synoidal', I guess it would behave exactly like AC, and could be converted to DC with some diodes or something.

Damn! I'm so excited about it! lol
I was thinking of orange leds sticked inside the gauges, and something like a switch just like those from aircrafts to turn on and off each gauge led, each fan and a 'master power' (for a secondary PSU).


Just for the record: I called an electronic components shop and they said they don't have the "IC PC Board multi-purpose - 417". Is there any other I can use to build the PWD?
By the way: Where does it fit into your scheme ?

for the fan, you can put a voltmeter between the rpm sensor and like the 3.3 or 5 V rail, and it should even out somewhere, but it wont show a true RPM, just show changes in RPMs.

tempos can be measured with an ohmmeter and a thermistor, it should have a reference of what resistances are what temps.

then voltage... well... just use the voltage probes.

Yeah, I figured I'd need some IC to keep the needle steady...

But maybe some transistor trick would do the job...


Oh, how does an 'ohmmeter' work? Is it used in serial or paralell?


BTW: how do I spot the voltage probes on my MB?
It's a (deffective) TUV-4X for now. Maybe I'll get myself a CUV-4X temporarily, but I'll most likelly upgrade the hole the swear filter's here for a reason -eobard to a '64 939. lol

if your mesuring voltage or resistance its paralell but if your mesuring current its in serise.
If you are speaking of the mesurment points, on alot of board they will be small round soldered pads and will sometimes have the referance voltage printed on the PCB beside them. You may have to get a repair guide to get dedicated test points. Although there are many points that can be used as test points that arent used by technitions.

Well, I guess I found something usefull for the RPMs...
This forum might be of help. =)


But, er... Just thought something: Wouldn't the PWM affect the RPM's pulses...?
I mean, is it possible to have some 'wave interpolation' where the fan would try to send a pulse, but is not beeing fed by the 12V?


By the way, Skeith:
The components stores don't have the "IC PC Board multi-purpose - 417".
Where exactly does it fit in your scheme ?
Is there any 'similar' I can use?

No basicaly the fan uses a small hall effect sensor (a magnetic sensor). The hall effect sensor acts like a small transistor and swithes the signal line to ground (through a puldown resistor to keep from direct shorting) I dont beleive the fan needs 12v to pull the signal to ground. It just needs a fixed ground plain. The PWM doesnt effect the pulses I have used the PWM on my computer and the RPMs read just fine. Also because the frequancy of the PWM is so high its a very low probablility that even if the fan required 12v it wouldent be off long enough to efect anything.

The board I bought from radio shack, so other supplyers might not have it. any prototypeing board will do you'll just have to comprimize when building it if its a different style board. Bassicly all you have to do is make sure all the connections are hooked up as they show in the shcematic, It doesnt have to be layed out exactly as I have it in the guide, just did that for people that are less adept at problem solving in their heads and might have trouble finding out where to place the components.
I have the actuall PCB template almost done. I'll try to post it with a guide on how to make a homemade printed circuit board with a readily available etching kit by tomorrow.

Oh, sorry... Read 'IC' and thought it was an IC, not a PCB board... LOL

Sorry sorry, really. My bad. lol

Yeah thats ok. The IC just means that it made to ocomadate ICs on it.

So anyone has any clue on the RPM thing?

And is it possible to measure temperatures from 20 to 100°C, with 20°C outputting like 8V and 100°C outputting like 16V DC? Maybe with the circiut beeing fed by +12V and -5V...

I mean, the only voltmeters I've found were from car batteries, and the scale is from 8 to 16~17V...

http://www.mpja.com/listitems.asp?dept=53&main=51&type=1

plenty of meters there.

http://www.allelectronics.com/cgi-bin/category/385/Meters_(Panel).html
http://www.halted.com/commerce/catalog/spcategory.jsp?category_id=3003&czuid=1139428338156
http://www.xcess.com/GME/Analog Panel Meters.htm
http://www.sayal.com/SAYALtop21_index.asp?ListCLASS=Panel Meters


theres a list of stuffs i found, should be some nice pickins.

I'll look for those specific models here in my country. =)

The car battery voltmeters are a bit too expensive for my taste, and they "only" go from 8 to 16V or so (also, a bit too high for my taste).

So... I can still mod'em, right? Hehehe
The ones from MPJA seem to be easy to make'em smaller and round (maybe cutting off a bit of the needles).

But well, I guess I still need to know what kind of voltmeters i'll need (depending on the circuitry I manage to get, right?), so I'll leave to buy em after the scheme has been planned (by a third party, probably paying for it, I guess :-\).


Thanks a lot, man! =)