I need to replace two hard-to-find 70 mm 12V DC 3-wire fans.

Hey,

just found your thread via the Part No. of the fans of the Sayno PLV-Z4.
Recently bought a used Sanyo Z4 and anyway I'm just a bit annoyed by the rattling noise those fans make. That's why I was looking for suitable fans to replace those Sanyo used.

So according to your findings there's no suitable 70mm 12V fan out there on the market, than can give the projector the needed tachometer signal?

For example something like this Papst fan does also provide a tachometer-signal...or is the signal the projector expects different from those which mainboards use?

 

Resurrecting this still relevant thread.

I'm not logged in that often, and apparently notifications on my threads is off in some settings somewhere.

Hi nattfoedd!

Thanks for stopping by in the ol' thread o' dread regarding the Sanyo Z4 fans and their noises!

Recently bought a used Sanyo Z4 and anyway I'm just a bit annoyed by the rattling noise those fans make. That's why I was looking for suitable fans to replace those Sanyo used.

So according to your findings there's no suitable 70mm 12V fan out there on the market, than can give the projector the needed tachometer signal?

For example something like this Papst fan does also provide a tachometer-signal...or is the signal the projector expects different from those which mainboards use?

It is a rattling noise indeed.

I am useless at searching for replacements of electronic components because:

1. I'm limited to retail outlets, which is severely limited when it comes to raw electronic parts.

2. Google, etc. can find lots of references to chip plants, pdfs and parts stockpiles in Taiwan and China, but rarely help a person find a part, even less a place where he/she can buy it.

3. I don't have any experience sourcing parts, except this kind of situation which has returned throughout my life. There's always something broken that needs a ridiculously specific part that is manufactured for less than a dollar, but the only one who can sell it to me wants to order it via two other industrialized nations and charge over 300 dollars for it.

Venting a little frustration there. Sorry.

So to answer your question: I'm absolutely sure there's a whole category of tach-signaling fans that are compatible with the Sanyo Z4 motherboard.

I just don't know of a way to tell!
I wish I knew the following:

A: What is this kind of tach signal called?
B: Does it have a term that is not specific to a manufacturer?

If you find out, please put it in this thread!

To reiterate, the tach signal appears give max speed by DC=+Vcc and rotation stopped is given by DC=0V

The RPM of the unit is given somehow in proportion to the pulse width (PWM duty cycle). The precious little info in the data sheets tell me all you need is the right experience to understand everything about this tach signal.

Edit:
However, as I found before: my 555-circuit with 50% duty cycle appears as 1600 RPM.
The simplest guess is that RPM is in linear proportion to the PWM duty cycle on the tach pin.

R = k * C

R := fan rate in RPM
C := duty cycle between 0-1
k := MAX rpm = 1600 * 2 = 3200 rpm

However, it could devilishly relate to the driving PWM on the power pin of the fan, or be dependent on frequency as well, but I tend to think they chose a simple solution.

Edit: The single linear scale would also be consistent with the metaphor "tachometer" which is a usually a linear dial instrument.



Here's a sad update on my Z4: Since my "hack" the three radial fans have given up too. Yes that's right there are three radial and two axial fans for a total of five whopping fan rattlers in there.

The two radial fans under the big filter in the back, are really trenched under the optic path, right on top of the panel cleaning holes. I can hear the curses I could be thinking as I try to get to them. :/



I called Sanyo's official service center in my city, they want $650 for replacing all five fans, including the parts. Just the spare fans cost $300. They have to order them from another european service center, who order them from Sanyo in Japan.

I will give it a go myself again.
Any help greatly appreciated as always.
I'll keep you posted.

I hope you return to the thread, nattfoedd!

 

Sounds liike common 3 wire fans to me. Since this thread was started nearly all fans have the tach wire and NewEgg has tons of different sizes. 70mm wasn't uncommon on some CPU heat sinks.

 

Sounds liike common 3 wire fans to me. Since this thread was started nearly all fans have the tach wire and NewEgg has tons of different sizes. 70mm wasn't uncommon on some CPU heat sinks.

Thanks, that's good input, but what do you mean with common 3-wire fans? I suppose, by the reference to NewEgg, that you mean the kind of 3rd wire found in the cooling fans for the common PC? That has been my guess as well, I just didn't have a good way to test it.

Noone would be happier than me if the "tachometer signal" which is treated as a self-explanatory metaphor everywhere, would be a standard thing.

If I google "fan tachometer signal" I find, among other things, this:
http://www.comairrotron.com/fan_monitoring.shtml

..which says "On most fan models, the tachometer will have 2 pulses per revolution."


Two pulses per revolution is a pure frequency-based signal, which according to the above quote is the most common, so the closes we get to a standard. I believe the PC form factor standard uses this definition.


Then I find this:
http://www.analog.com/library/analogdialogue/archives/38-02/fan_speed.html

..which says about 3-wire fans "while the ideal tach is representative of the actual speed of the fan, the PWM drive in effect “chops” the tach signal output and may produce erroneous readings."

..and "In order to be sure of a correct fan speed reading under PWM control, it is necessary to periodically switch the fan on long enough to get a complete tach cycle. "


My theory thus far is that the fans in the Z4 are not like "most fan models" but instead have a mysterious PWM output.

I would accept if I'm wrong and my circuit works due to some luck. I would love to understand the matter.

 

I seriously doubt they were anything more than today's common tach signal and in most cases the circuit that monitors that signal only does so to set a fault should the fan quit rotating. It usually cares not about the number of poles thus resultant frequency it sees.

I just mentioned NewEgg as I've spent about $10,000 with them over the years on various items, you can probably find these fans locally on an older CPU heat sink for $5 at a computer sales &/or repair shop - they may even give it to you.

 

My theory thus far is that the fans in the Z4 are not like "most fan models" but instead have a mysterious PWM output.

True PWM fans didn't come along until recently and most have 4 wires. If they used the tach wire from a 3 wire fan in a PWM feedback loop it's going to be a normal fan.

 

Well, the idea came from the manufacturer documents.

This you can see in the link to nmbtc.com, posted by eng1ne above, and the post just before that by Bertus.

The 9 at the end of the NMB part numbers I got, is called "Sensor Type" as distinct from:

0 Standard type
8 2-speed type
7 Temperature detecting variable speed type / PWM control type
6 Temperature detecting variable speed type / Sensor type
5 2-speed type / Sensor type

The last component of the part number, which these fans don't have printed on them, is read as:

00 - Locked Rotor Alarm Signal (Standard)
01-99 - Potential custom variants of "Locked Rotor" or "Tachometer" signals:

01-49 Locked Rotor Alarm Signal (Custom)
50 - Tachometer Signal (Standard)
51-99 Tachometer Signal (Custom)

So the most probable way to read this is: Something that NMB calls "Special Control Function = Sensor Type, Individual Specifications = Standard Locked Rotor Alarm Signal". I have no idea what that means.
Edit: clarified the above sentence.

Thanks for your insights and your serious doubt, and any other helpful stuff you can do here.

 

I doubt it means anything. If one of the fans is still working why don't you just try it in a PC that also has a three wire socket.

Download SpeedFan and see if it picks up on the fan and shows a speed.

 

I doubt it means anything. If one of the fans is still working why don't you just try it in a PC that also has a three wire socket.

Download SpeedFan and see if it picks up on the fan and shows a speed.

I'll try that, in fact I'll give all the stuff in this thread another go shortly, as soon as I have a evening to spend on it. I'll keep you posted.

Thanks!

 

Fans are in stock at service centres of sanyo and cost around 35 euros for the radial ones here discussed. Keep in mind that Sanyo promised to keep parts in stock for at least 8 years after they sell any projector.

 

The tach outputs are usaully a standard 2 or 4 pulse per RPM, I forget which is the most common but it's like 95% are of that type so most any should do.

Go to http://www.newegg.com then drill down through the menu on the left until you get to 70mm fans.

In my opinion Scythe makes the best fans and ThermalTake is also a good fan along with a couple of other name brands. As you go down the line from there they become nothing more than generic chinese fans but they still operate the same, usually cheaper bearings, noisier and less air output for the size.

I can bet you 0.05 these are nothing more than common 3-wire fans they've assigned a special part # (and price) to.

 

hmm marshall, so just copy the amperage / fan size and one is settled?

I can imagine different fans running different rpm's although they are they same size and amperage. The airflow has to be at least the same or more then in the original situation of course. One might find a fan that does the job better but also at the cost of more sound than originally was heard (The sanyo z5 is very quiet projector, thats why i got it in the first place). I settle for the original fan at the service centre right now; altough 300% paying to much.

if i am unlucky and another fan starts whining its good to try the scythe option..
might as well do the job properly or even better, who knows?? ,
Still strange stuff: amperage doesnt say much about: magnets and copper windings inside the fan !!! I would die to know just the amount of air the original fan pushes trough at min / max!!! (Generated air flow/ CFM )

 

Due to the "new age" of quiet computers being the in thing you'll see a lot of very low RPM/CFM fans on the market, just get a decent one that's around or better than the observed midrange CFM in that size.

 

here are the specs for the radial fans: http://www.widus.co.kr/eng/sub3/pro1_3_1.php

SERIES P/N Rated voltage Rated current Rotating speed Maximum airflow Maximum voltage Noise Download
[Vdc] [A] min-1 [m³/min] [CFM] [Pa] [dBA]
SF SF51H12 DC12 0.16 5800 0.15 5.3 175 33
SF SF61H12 DC12 0.15 4600 0.18 6.3 145 32

from the plv-z3... i think they're the same as in the z4...

 

Those kind of fans are a lot harder to find, they're squirrel cages. You might look around eBay or some of the electronic wholesale main and bargain websites