Power Fan below threshold

Richard

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Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I recently install a ASUS motherboard in my old case and see a message
"Power Fan below threshold" from the ASUS utility software. There is a
CPU fun and a CHA fun for the case. I can not find the POWER fun for
the POWER supply.

Does that mean the Power Supply Fun stop working? Do I need to buy a
new Power Supply 300W?

Thank you in advance
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

"Richard" <ehope8@gmail.com> wrote in message
news:1123559373.575160.208030@o13g2000cwo.googlegroups.com...
>I recently install a ASUS motherboard in my old case and see a message
> "Power Fan below threshold" from the ASUS utility software. There is a
> CPU fun and a CHA fun for the case. I can not find the POWER fun for
> the POWER supply.
>
> Does that mean the Power Supply Fun stop working? Do I need to buy a
> new Power Supply 300W?
>
> Thank you in advance
Unless a connection is made to the fan, if the motherboard has monitoring
for this input, it is going to report 'below threshold'. There should be a
connector on the motherboard for the power fan. Many power supplies now
have a extra connection to feed the tacho signal from the power fan to
this. You don't say which motherboard, so we cannot help you to find the
connector. However, provided the machine is stable, working well, and
temperatures are OK, just turn off monitoring of this in the CMOS setup.
Unfortunately, '300W', really means nothing!. The key figures are normally
the peak current available on particular rails (rather than the total
delivered by the supply), and different makes of supply, vary wildly in
how accurate/optimistic their reported power outputs are. Again you don't
say what motherboard, and processor are involved, with the power needed
varying massively between different processors on the market (for example,
the power needed for a fast P4 system, with an upmarket video card, can
easily be 100W more than an AMD64, with a slightly 'lesser' video card...

Best Wishes
 

Paul

Splendid
Mar 30, 2004
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Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <1123559373.575160.208030@o13g2000cwo.googlegroups.com>,
"Richard" <ehope8@gmail.com> wrote:

> I recently install a ASUS motherboard in my old case and see a message
> "Power Fan below threshold" from the ASUS utility software. There is a
> CPU fun and a CHA fun for the case. I can not find the POWER fun for
> the POWER supply.
>
> Does that mean the Power Supply Fun stop working? Do I need to buy a
> new Power Supply 300W?
>
> Thank you in advance

There are several options for power supplies.

A cheap power supply might have no monitoring capability at
all. If there is no monitoring cable on the PSU, then the
PSU cannot talk to the motherboard.

If the PSU has a two wire cable, with a three pin connector
on the end, that is a fan monitor cable. The two wires are
"tachometer_output" and GND. When this PSU cable is connected
to a fan header on the motherboard, the motherboard should
be able to measure the RPMs. It does this by measuring the
period between pulses.

If the PSU has a two wire cable, with a two pin connector
on the end, this could be a thermistor output. A negative
tempco thermistor, nominal resistance 10K ohms at 25C, with
a beta of 3435, would be the typical component used. Most
monitoring chips and associated software would expect this
kind of component, and the temperature is computed with
the assumption that the thermistor is one of that type.
The thermistor inside the PSU allows the motherboard to
measure the temperature of the PSU, and with the right
software, you might be able to raise an alarm if the PSU is
too hot. Recent motherboards don't seem to have the
necessary two pin header - my P4B has a TRPWR header, but
I don't think my other boards have one of those.

Since the fan speed is typically measured by measuring
the period between pulses from the fan, the measurement
register has a limit to the amount of counts it can hold,
before it overflows. The slower the fan goes, the more
counts that accumulate in the counter. The operation
looks something like this:

| <--- Motor pulses twice per one fan revolution ---> |
_____________ _____________ ___
___| |______________| |____________|

_ _ _ _ _ _ _
_| |_| |_| |_| |_| |_| |_| |_

| <- seven counts in total-> |
counter = 0x07 hex

The monitor chip makes those tiny measurement pulses, and the
frequency of the pulses has to be selected to give good
resolution and good min to max range. The pulses are created
by a chain of divide-by-two flops, and the BIOS sets up the
right value for the divide chain before Windows boots. I think
both the BIOS and the OS/applications have access to the
monitor chip, and it could be that the OS/applications are
not allowed to change the divider chain (there is no standard
for the interface that I've heard of, so this is just a guess).

Now, imagine a thought experiment. The BIOS designer at Asus
expects the fan to spin at 3000 RPM. They set the divider so
that the 8 bit counter (max value 255 decimal) will catch
128 pulses in the time it takes the fan to generate one full
pulse. Now, the customer gets the motherboard, and plugs in
a PSU with a fan that spins at 1500 RPM. When spinning at 1500
RPM, the pulses are stretched out by a factor of two. Instead
of 128 pulses accumulating in the 8 bit counter, a total of
256 accumulate in the counter. That is one more pulse than
the counter can hold, so an overflow bit is set (or equivalent
thereof).

When the software detects an overflow, it doesn't know if the
total counts are 256 or a gazillion (when the fan stops). The
fan speed is somewhere between 0 and 1500RPM, but due to the
measurement method, there is no way to know. In a situation
like this, the BIOS reports "0 RPM", even though you can see
your fan is still spinning.

So, in some cases, there may still be room in the divider
chain, to adjust the frequency of the measurement pulses, and
bring the pulse period measurement back within the 1..255
count range limit of the counter. But whether the software
is allowed to do that or not, is something I cannot answer.

You may ask the question, "why do they measure the period
of the pulses, when they could count the revolutions ?".
The answer is, the period measurement method allows the
speed of the fan to be computed faster. The measurement
time is bounded by the time it takes to overflow the
counter. The question one has to ask, is why the silicon
chip designers could not use a larger register to accumulate
counts, like maybe a 16 bit register. With sufficient register
bits, there wouldn't even be a need to adjust the divider
chain.

The RPM value you see, is not the value extracted raw from
the chip. The readings are averaged, to reduce the jitter
in the values seen. Averaging the values increases the
latency in seeing a change in fan speed, but it avoids
the RPMs being annoyingly unreadable by a human.

For monitor chips that sit on the SMBUS, rather than an
LPC bus, it is possible for two software programs to
interfere with the readout of registers from the monitor
chip. When this happens, a program like MBM5, Speedfan,
or Asus Probe, might report the fan at one moment is 0 RPM,
and at the next instant is 10000 RPM. The SMBUS has no
semaphore to prevent simultaneous accesses by two programs,
and the serial data on the SMBUS is cut off in mid access.
The result is garbage values seen by the software.

Much of the above is supposition and assumptions on my
part, as the datasheets do not describe in clear English
how this stuff works. I hope (most of) the above is correct.
At least it may help explain why programs readout "0 RPM"
when the fan is still spinning.

HTH,
Paul
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Paul wrote:
>
> In article <1123559373.575160.208030@o13g2000cwo.googlegroups.com>,
> "Richard" <ehope8@gmail.com> wrote:
>
> > I recently install a ASUS motherboard in my old case and see a message
> > "Power Fan below threshold" from the ASUS utility software. There is a
> > CPU fun and a CHA fun for the case. I can not find the POWER fun for
> > the POWER supply.
> >
> > Does that mean the Power Supply Fun stop working? Do I need to buy a
> > new Power Supply 300W?
> >
> > Thank you in advance
>
> There are several options for power supplies.
>
> A cheap power supply might have no monitoring capability at
> all. If there is no monitoring cable on the PSU, then the
> PSU cannot talk to the motherboard.
>
> If the PSU has a two wire cable, with a three pin connector
> on the end, that is a fan monitor cable. The two wires are
> "tachometer_output" and GND. When this PSU cable is connected
> to a fan header on the motherboard, the motherboard should
> be able to measure the RPMs. It does this by measuring the
> period between pulses.
>
> If the PSU has a two wire cable, with a two pin connector
> on the end, this could be a thermistor output. A negative
> tempco thermistor, nominal resistance 10K ohms at 25C, with
> a beta of 3435, would be the typical component used. Most
> monitoring chips and associated software would expect this
> kind of component, and the temperature is computed with
> the assumption that the thermistor is one of that type.
> The thermistor inside the PSU allows the motherboard to
> measure the temperature of the PSU, and with the right
> software, you might be able to raise an alarm if the PSU is
> too hot. Recent motherboards don't seem to have the
> necessary two pin header - my P4B has a TRPWR header, but
> I don't think my other boards have one of those.
>
> Since the fan speed is typically measured by measuring
> the period between pulses from the fan, the measurement
> register has a limit to the amount of counts it can hold,
> before it overflows. The slower the fan goes, the more
> counts that accumulate in the counter. The operation
> looks something like this:
>
> | <--- Motor pulses twice per one fan revolution ---> |
> _____________ _____________ ___
> ___| |______________| |____________|
>
> _ _ _ _ _ _ _
> _| |_| |_| |_| |_| |_| |_| |_
>
> | <- seven counts in total-> |
> counter = 0x07 hex
>
> The monitor chip makes those tiny measurement pulses, and the
> frequency of the pulses has to be selected to give good
> resolution and good min to max range. The pulses are created
> by a chain of divide-by-two flops, and the BIOS sets up the
> right value for the divide chain before Windows boots. I think
> both the BIOS and the OS/applications have access to the
> monitor chip, and it could be that the OS/applications are
> not allowed to change the divider chain (there is no standard
> for the interface that I've heard of, so this is just a guess).
>
> Now, imagine a thought experiment. The BIOS designer at Asus
> expects the fan to spin at 3000 RPM. They set the divider so
> that the 8 bit counter (max value 255 decimal) will catch
> 128 pulses in the time it takes the fan to generate one full
> pulse. Now, the customer gets the motherboard, and plugs in
> a PSU with a fan that spins at 1500 RPM. When spinning at 1500
> RPM, the pulses are stretched out by a factor of two. Instead
> of 128 pulses accumulating in the 8 bit counter, a total of
> 256 accumulate in the counter. That is one more pulse than
> the counter can hold, so an overflow bit is set (or equivalent
> thereof).
>
> When the software detects an overflow, it doesn't know if the
> total counts are 256 or a gazillion (when the fan stops). The
> fan speed is somewhere between 0 and 1500RPM, but due to the
> measurement method, there is no way to know. In a situation
> like this, the BIOS reports "0 RPM", even though you can see
> your fan is still spinning.
>
> So, in some cases, there may still be room in the divider
> chain, to adjust the frequency of the measurement pulses, and
> bring the pulse period measurement back within the 1..255
> count range limit of the counter. But whether the software
> is allowed to do that or not, is something I cannot answer.
>
> You may ask the question, "why do they measure the period
> of the pulses, when they could count the revolutions ?".
> The answer is, the period measurement method allows the
> speed of the fan to be computed faster. The measurement
> time is bounded by the time it takes to overflow the
> counter. The question one has to ask, is why the silicon
> chip designers could not use a larger register to accumulate
> counts, like maybe a 16 bit register. With sufficient register
> bits, there wouldn't even be a need to adjust the divider
> chain.
>
> The RPM value you see, is not the value extracted raw from
> the chip. The readings are averaged, to reduce the jitter
> in the values seen. Averaging the values increases the
> latency in seeing a change in fan speed, but it avoids
> the RPMs being annoyingly unreadable by a human.
>
> For monitor chips that sit on the SMBUS, rather than an
> LPC bus, it is possible for two software programs to
> interfere with the readout of registers from the monitor
> chip. When this happens, a program like MBM5, Speedfan,
> or Asus Probe, might report the fan at one moment is 0 RPM,
> and at the next instant is 10000 RPM. The SMBUS has no
> semaphore to prevent simultaneous accesses by two programs,
> and the serial data on the SMBUS is cut off in mid access.
> The result is garbage values seen by the software.
>
> Much of the above is supposition and assumptions on my
> part, as the datasheets do not describe in clear English
> how this stuff works. I hope (most of) the above is correct.
> At least it may help explain why programs readout "0 RPM"
> when the fan is still spinning.
>
> HTH,
> Paul

Paul

I posted the other day about my enermax PS (EG465P VE-SFCA), not being
able to send a rpm signal to monitor via asus probe etc.
PS Fan has a 2 pin lead for the MB, another poster said the MB (K8V SE
DLX) can only read 2 rpm's at a time and I should disconnect the chassis
fan rpm wire from the 2 wire chassis fan lead if i want the PS fan rpm.
Will this work?

Thx
Gordon
 

Paul

Splendid
Mar 30, 2004
5,267
0
25,780
0
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <42F8FEF4.BAFAF19D@shaw.ca>, Gordon Scott
<gordsmail@NOSPAMshaw.ca> wrote:

>
> Paul
>
> I posted the other day about my enermax PS (EG465P VE-SFCA), not being
> able to send a rpm signal to monitor via asus probe etc.
> PS Fan has a 2 pin lead for the MB, another poster said the MB (K8V SE
> DLX) can only read 2 rpm's at a time and I should disconnect the chassis
> fan rpm wire from the 2 wire chassis fan lead if i want the PS fan rpm.
> Will this work?
>
> Thx
> Gordon

I cannot say I like Enermax's model numbering system. There are
several EG465P VE models on Newegg. I tried looking at the pictures,
but cannot see any monitor cables in the pictures. In the
reviewer comments section, one guy mentioned that his power supply
had a two pin cable, which is apparently a temperature measurement
option for the power supply (you would need a thermistor for something
like this to work). If your power supply came with a
manual, you might look for an explanation in there. The
claim is, the PSU will function without monitoring external
temperature, so there is no need to connect the two wire/two pin
connector to anything.

If the PSU has a three pin connector, with two wires on it,
that could be the fan speed monitor. Try another fan header
on the motherboard, and see if any reading results. According
to the K8V SE manual (in the BIOS section), only the CPU fan header
and the Chassis fan header are monitored. So, that means you
should be connecting the PSU three pin monitor cable to your
chassis header. You can connect your chassis fan to the
PWR_FAN header, so the chassis fan at least gets +12V to spin
the fan. (The datasheet for the Winbond 83697HF Super
I/O chip, says it only has two fan monitor channels. That means
the PWR_FAN header on your motherboard is not monitored - the
tacho wire on that header will not be connected to anything
on the motherboard. And that is why the BIOS screen in your
user manual doesn't have any entry for PWR_FAN RPMs.)

I'd download a manual from the Enermax web site, but I doubt
they are clever enough to provide a manual. Have a look through
the paper manual that came in the box, and verify the function
of those two and three pin connectors. I prefer to research
these things and give a definite answer, and right now, I've
got nothing I can use as a source of info to help you with
your Enermax supply. If the three pin connector has a label
on it, that might give a hint as to whether it truly is
intended for fan speed monitoring.

Paul
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Hi,

You sound like someone to try my latest wild idea on.

I have not looked at the Intel spec for fans yet, you seem to have
information from it.

I installed a "Zalman CNPS7700 AlCu CPU cooler" with Fanmate 2 for
controlling the fan speed.

It does such a great job cooling my CPU that even when set to the lowest
speed my CPU temperatures at max. load are way below normal temps.

Before with the Intel supplied fan the CPU temperatures were so high that
the CPU was limiting most of the time. (P4 640)

With the fan speed ~960 RPM both the BIOS and the Probe program complained
that the fan had failed.

The point that they stopped complaining was about 1200 RPM.

The ~960 fan speed was way too fast, there was noise being generated that
was not necessary.

I thought about patching the probe program and the BIOS to not complain
about the slow fan speeds, but I had not gotten around to looking into that
possibility.

Then I purchased a front panel display which has a Fanmate type control and
CPU fan speed display along with CPU, HDD and CASE temperature readouts.

The minimum fan speed is inside the special chip for the display panel which
again is too fast, 1250 RPM.

So the patching of limits idea will no longer fly. A hardware solution is
needed now.

I did some searching in my very old data books for a frequency doubler chip
and found one, but it was a reference to a chip documented in a book I did
not have and due to the book being 30 years old it must have been replaced
several times.

Today there probably many ways to do a frequency doubler and make the output
meet the Intel fan requirements.

So you can have a much slower fan speed and all the monitoring programs will
be quite happy but displaying the fan speed twice what it really is.

Will this hardware solution fly?

--

Stephen H. Fischer

Paul wrote:
> In article <1123559373.575160.208030@o13g2000cwo.googlegroups.com>,
> "Richard" <ehope8@gmail.com> wrote:
>
>> I recently install a ASUS motherboard in my old case and see a message
>> "Power Fan below threshold" from the ASUS utility software. There is a
>> CPU fun and a CHA fun for the case. I can not find the POWER fun for
>> the POWER supply.
>>
>> Does that mean the Power Supply Fun stop working? Do I need to buy a
>> new Power Supply 300W?
>>
>> Thank you in advance
>
> There are several options for power supplies.
>
> A cheap power supply might have no monitoring capability at
> all. If there is no monitoring cable on the PSU, then the
> PSU cannot talk to the motherboard.
>
> If the PSU has a two wire cable, with a three pin connector
> on the end, that is a fan monitor cable. The two wires are
> "tachometer_output" and GND. When this PSU cable is connected
> to a fan header on the motherboard, the motherboard should
> be able to measure the RPMs. It does this by measuring the
> period between pulses.
>
> If the PSU has a two wire cable, with a two pin connector
> on the end, this could be a thermistor output. A negative
> tempco thermistor, nominal resistance 10K ohms at 25C, with
> a beta of 3435, would be the typical component used. Most
> monitoring chips and associated software would expect this
> kind of component, and the temperature is computed with
> the assumption that the thermistor is one of that type.
> The thermistor inside the PSU allows the motherboard to
> measure the temperature of the PSU, and with the right
> software, you might be able to raise an alarm if the PSU is
> too hot. Recent motherboards don't seem to have the
> necessary two pin header - my P4B has a TRPWR header, but
> I don't think my other boards have one of those.
>
> Since the fan speed is typically measured by measuring
> the period between pulses from the fan, the measurement
> register has a limit to the amount of counts it can hold,
> before it overflows. The slower the fan goes, the more
> counts that accumulate in the counter. The operation
> looks something like this:
>
> | <--- Motor pulses twice per one fan revolution ---> |
> _____________ _____________ ___
> ___| |______________| |____________|
>
> _ _ _ _ _ _ _
> _| |_| |_| |_| |_| |_| |_| |_
>
> | <- seven counts in total-> |
> counter = 0x07 hex
>
> The monitor chip makes those tiny measurement pulses, and the
> frequency of the pulses has to be selected to give good
> resolution and good min to max range. The pulses are created
> by a chain of divide-by-two flops, and the BIOS sets up the
> right value for the divide chain before Windows boots. I think
> both the BIOS and the OS/applications have access to the
> monitor chip, and it could be that the OS/applications are
> not allowed to change the divider chain (there is no standard
> for the interface that I've heard of, so this is just a guess).
>
> Now, imagine a thought experiment. The BIOS designer at Asus
> expects the fan to spin at 3000 RPM. They set the divider so
> that the 8 bit counter (max value 255 decimal) will catch
> 128 pulses in the time it takes the fan to generate one full
> pulse. Now, the customer gets the motherboard, and plugs in
> a PSU with a fan that spins at 1500 RPM. When spinning at 1500
> RPM, the pulses are stretched out by a factor of two. Instead
> of 128 pulses accumulating in the 8 bit counter, a total of
> 256 accumulate in the counter. That is one more pulse than
> the counter can hold, so an overflow bit is set (or equivalent
> thereof).
>
> When the software detects an overflow, it doesn't know if the
> total counts are 256 or a gazillion (when the fan stops). The
> fan speed is somewhere between 0 and 1500RPM, but due to the
> measurement method, there is no way to know. In a situation
> like this, the BIOS reports "0 RPM", even though you can see
> your fan is still spinning.
>
> So, in some cases, there may still be room in the divider
> chain, to adjust the frequency of the measurement pulses, and
> bring the pulse period measurement back within the 1..255
> count range limit of the counter. But whether the software
> is allowed to do that or not, is something I cannot answer.
>
> You may ask the question, "why do they measure the period
> of the pulses, when they could count the revolutions ?".
> The answer is, the period measurement method allows the
> speed of the fan to be computed faster. The measurement
> time is bounded by the time it takes to overflow the
> counter. The question one has to ask, is why the silicon
> chip designers could not use a larger register to accumulate
> counts, like maybe a 16 bit register. With sufficient register
> bits, there wouldn't even be a need to adjust the divider
> chain.
>
> The RPM value you see, is not the value extracted raw from
> the chip. The readings are averaged, to reduce the jitter
> in the values seen. Averaging the values increases the
> latency in seeing a change in fan speed, but it avoids
> the RPMs being annoyingly unreadable by a human.
>
> For monitor chips that sit on the SMBUS, rather than an
> LPC bus, it is possible for two software programs to
> interfere with the readout of registers from the monitor
> chip. When this happens, a program like MBM5, Speedfan,
> or Asus Probe, might report the fan at one moment is 0 RPM,
> and at the next instant is 10000 RPM. The SMBUS has no
> semaphore to prevent simultaneous accesses by two programs,
> and the serial data on the SMBUS is cut off in mid access.
> The result is garbage values seen by the software.
>
> Much of the above is supposition and assumptions on my
> part, as the datasheets do not describe in clear English
> how this stuff works. I hope (most of) the above is correct.
> At least it may help explain why programs readout "0 RPM"
> when the fan is still spinning.
>
> HTH,
> Paul
 

Paul

Splendid
Mar 30, 2004
5,267
0
25,780
0
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <pxXKe.5041$RS.273@newsread3.news.pas.earthlink.net>, "Stephen
H. Fischer" <sfischer1@mindspring.com> wrote:

> Hi,
>
> You sound like someone to try my latest wild idea on.
>
> I have not looked at the Intel spec for fans yet, you seem to have
> information from it.
>
> I installed a "Zalman CNPS7700 AlCu CPU cooler" with Fanmate 2 for
> controlling the fan speed.
>
> It does such a great job cooling my CPU that even when set to the lowest
> speed my CPU temperatures at max. load are way below normal temps.
>
> Before with the Intel supplied fan the CPU temperatures were so high that
> the CPU was limiting most of the time. (P4 640)
>
> With the fan speed ~960 RPM both the BIOS and the Probe program complained
> that the fan had failed.
>
> The point that they stopped complaining was about 1200 RPM.
>
> The ~960 fan speed was way too fast, there was noise being generated that
> was not necessary.
>
> I thought about patching the probe program and the BIOS to not complain
> about the slow fan speeds, but I had not gotten around to looking into that
> possibility.
>
> Then I purchased a front panel display which has a Fanmate type control and
> CPU fan speed display along with CPU, HDD and CASE temperature readouts.
>
> The minimum fan speed is inside the special chip for the display panel which
> again is too fast, 1250 RPM.
>
> So the patching of limits idea will no longer fly. A hardware solution is
> needed now.
>
> I did some searching in my very old data books for a frequency doubler chip
> and found one, but it was a reference to a chip documented in a book I did
> not have and due to the book being 30 years old it must have been replaced
> several times.
>
> Today there probably many ways to do a frequency doubler and make the output
> meet the Intel fan requirements.
>
> So you can have a much slower fan speed and all the monitoring programs will
> be quite happy but displaying the fan speed twice what it really is.
>
> Will this hardware solution fly?

Well, as an unemployed engineer, I have actually thought about various
projects I could turn into a business opportunity. The frequency
doubler idea was an item on my list.

The requirements would be:

1) Circuit must be tiny, so it could plug directly to the
motherboard header.
2) Circuit must run from the +12V of the fan.
3) Must be able to tolerate pulsed power on +12V, and work even
if the +12V drops to 5V or so.
4) The pulse doubler must be able to deal with the 12V pulses of
the fan.
5) The pulse doubler output should be open collector, capable of
dealing with a pullup to +12V on the motherboard. Some motherboards
will use +5V or maybe even a lower voltage for their pullup.
6) Circuit must be bloody cheap. (That is the hard part. With
unlimited development funds, you just make a chip.)

I have found a cheap chip (maybe $1 or less) for the basic function.
I won't say what the chip is. The level of integration is probably
not high enough to meet the price point. I would need a voltage
regulator, an external buffer transistor, a couple caps for filtering
the regulated power and so on. This is making the solution a bit
on the large side, and the voltage regulator could be more expensive
than the doubler chip :)

I will give you an idea for free. The reason I'm giving this one
away for free, is it is too expensive to commercialize, but is
just fine for someone to build for themselves. It is simple enough,
that anyone with some basic wiring skills could try it.

This method would be termed an optical tachometer. Basically you
bounce a light off the blades of the fan. Normally, the fan produces
two pulses per revolution, but with a seven blade fan, you get seven
pulses per revolution. That is frequency multiplication by a factor
of 3.5 .

This device is a real beauty.

http://www.sharp.co.jp/products/device/lineup/data/pdf/datasheet/gp2a200l_j.pdf

It contains a modulated light source. Modulated light helps prevent
other stray sources of light, from influencing the detector. On the
photodetector side, they use synchronous detection (so the module
can only "see" the energy from the modulated light source). You will
notice the device has an open collector transistor output, suitable
for connecting directly to a motherboard fan header. The rest of
the details I put in a previous post:

http://groups.google.ca/group/alt.comp.periphs.mainboard.asus/msg/9b603feaec516cd9?dmode=source&hl=en

The Sharp module is about $5.00. Back in April, it was listed on
Digikey, and might still be there. As a safety precaution, in case
the module exhibits instability, you could also purchase a small
capacitor, that goes across the +5V and GND used to power the
chip. The capacitor might not even be necessary. You will also
need a three pin female fan connector, a Molex disk drive "Y" cable
(to get the +5V power for the module), and a bit of wire. The module
has three pins on it - one wire goes to the fan connector, the
other two wires go to +5V and GND on the disk drive cable.

The tricky part, will be building a mechanical support, to hold the
module so it illuminates the fan blades properly.

Have fun :)
Paul
 

Butch

Distinguished
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Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

On Fri, 12 Aug 2005 20:04:26 -0400, nospam@needed.com (Paul) wrote:

>In article <pxXKe.5041$RS.273@newsread3.news.pas.earthlink.net>, "Stephen
>H. Fischer" <sfischer1@mindspring.com> wrote:
>
>> Hi,
>>
cut cut>>
>> So you can have a much slower fan speed and all the monitoring programs will
>> be quite happy but displaying the fan speed twice what it really is.
>>
>> Will this hardware solution fly?
>
>Well, as an unemployed engineer, I have actually thought about various
>projects I could turn into a business opportunity. The frequency
>doubler idea was an item on my list.
>
>The requirements would be:
cut cut
>other two wires go to +5V and GND on the disk drive cable.
>
>The tricky part, will be building a mechanical support, to hold the
>module so it illuminates the fan blades properly.
>
>Have fun :)
> Paul

This all would not be needed if the ASUS engineers or the BIOS
engineers made an extra selection in the BIOS to change the treshhold
RPM.
So engineers. Wake up.
(Note. I have the same problem with the original CPU blower. It runs
to slow in the 'silent' mode.

Butch
 
G

Guest

Guest
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Paul wrote:
> In article <pxXKe.5041$RS.273@newsread3.news.pas.earthlink.net>, "Stephen
> H. Fischer" <sfischer1@mindspring.com> wrote:
>
>> Hi,

>>
>> Today there probably many ways to do a frequency doubler and make the
>> output meet the Intel fan requirements.
>>
>> So you can have a much slower fan speed and all the monitoring programs
>> will be quite happy but displaying the fan speed twice what it really is.
>
> Well, as an unemployed engineer, I have actually thought about various
> projects I could turn into a business opportunity. The frequency
> doubler idea was an item on my list.
>
> The requirements would be:
>
> 1) Circuit must be tiny, so it could plug directly to the
> motherboard header.
> 2) Circuit must run from the +12V of the fan.
> 3) Must be able to tolerate pulsed power on +12V, and work even
> if the +12V drops to 5V or so.
> 4) The pulse doubler must be able to deal with the 12V pulses of
> the fan.
> 5) The pulse doubler output should be open collector, capable of
> dealing with a pullup to +12V on the motherboard. Some motherboards
> will use +5V or maybe even a lower voltage for their pullup.
> 6) Circuit must be bloody cheap. (That is the hard part. With
> unlimited development funds, you just make a chip.)

1)Tiny not necessarily, but yes plug in line to the fan cable.
There is lots of room inside most cases.
It must plug into the cable coming from the fan.
Then both the front panel display and the BIOS monitor would see
the double speed.

2-6) Perhaps add "able to handle large temperature change cycles".
Not be sensitive to temperature, as long as the output
remains two times the input. This means, while the internal
values may change with constant frequency, the output remains
two times the input. No calibration needed.

> I have found a cheap chip (maybe $1 or less) for the basic function.
> I won't say what the chip is.

Well that info might save some searching time, living here in Silicon Valley
I have found many chips to be made out of unatainum anyway. That's one
reason I am a dormant electronics hobbyist. Note the reference to a
thirty year old data book.

>The level of integration is probably
> not high enough to meet the price point. I would need a voltage
> regulator, an external buffer transistor, a couple caps for filtering
> the regulated power and so on. This is making the solution a bit
> on the large side, and the voltage regulator could be more expensive
> than the doubler chip :)

Not a good project to try and make money. Too many conditions.

a) User must have an Intel CPU that produces too much heat.
Intel will fix this or have already done so. Short time period.

b) A "Zalman CNPS7700 AlCu CPU cooler" must be installed and
be able to cool the CPU with low fan speed.
I wonder if this occurs with any other CPU Heatsink / fan products.

c) User must be building a low noise PC like a HTPC.
This is being done more and more. A home built PC or upgrade
being done by the user. A small number of people.

The best solution would be to put more money in Zalman's pocket,
not yours. They may have possibilities of reporting the fan speed
two times the actual speed that the fan is rotating much cheaper.

Perhaps in the future the BIOS and probe programs will have
the ability to set the lower limits. And the upper limits for Probe.
The high end fixed at 6000 is also a problem as you can not
see small changes.

The front panel will take a long time to include this capability
and the time that BIOS and Probe can be changed also may be long.

Start sending your cards and letters to ASUS and Zalman.

Zalman I suspect will be first to respond putting a little more circuits in
their Fanmate 3 or higher.

Selling the Fanmate 3 to existing customers might cover the development
costs for Zalman.

> I will give you an idea for free. The reason I'm giving this one
> away for free, is it is too expensive to commercialize, but is
> just fine for someone to build for themselves. It is simple enough,
> that anyone with some basic wiring skills could try it.
>
> This method would be termed an optical tachometer. Basically you
> bounce a light off the blades of the fan. Normally, the fan produces
> two pulses per revolution, but with a seven blade fan, you get seven
> pulses per revolution. That is frequency multiplication by a factor
> of 3.5 .
>
> This device is a real beauty.
>
> http://www.sharp.co.jp/products/device/lineup/data/pdf/datasheet/gp2a200l_j.pdf
>
> It contains a modulated light source. Modulated light helps prevent
> other stray sources of light, from influencing the detector. On the
> photodetector side, they use synchronous detection (so the module
> can only "see" the energy from the modulated light source). You will
> notice the device has an open collector transistor output, suitable
> for connecting directly to a motherboard fan header. The rest of
> the details I put in a previous post:
>
> http://groups.google.ca/group/alt.comp.periphs.mainboard.asus/msg/9b603feaec516cd9?dmode=source&hl=en
>
> The Sharp module is about $5.00. Back in April, it was listed on
> Digikey, and might still be there. As a safety precaution, in case
> the module exhibits instability, you could also purchase a small
> capacitor, that goes across the +5V and GND used to power the
> chip. The capacitor might not even be necessary. You will also
> need a three pin female fan connector, a Molex disk drive "Y" cable
> (to get the +5V power for the module), and a bit of wire. The module
> has three pins on it - one wire goes to the fan connector, the
> other two wires go to +5V and GND on the disk drive cable.
>
> The tricky part, will be building a mechanical support, to hold the
> module so it illuminates the fan blades properly.

Visit a new construction site and pick up 6-8" of # 12 copper wire,
or perhaps # 10 or # 8. This can be bent into any shape by hand
and will remain in place if not bumped.

> Have fun :)
> Paul

That sounds like a good and cheap idea and one that I did not think about.

Power Supply fan speed would be able to be monitored for the older PS
that do not have a monitoring connection.
 

Paul

Splendid
Mar 30, 2004
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Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <vRDLe.5623$WD.1459@newsread1.news.pas.earthlink.net>, "Stephen
H. Fischer" <sfischer1@mindspring.com> wrote:

>
> 1)Tiny not necessarily, but yes plug in line to the fan cable.
> There is lots of room inside most cases.
> It must plug into the cable coming from the fan.
> Then both the front panel display and the BIOS monitor would see
> the double speed.
>
> 2-6) Perhaps add "able to handle large temperature change cycles".
> Not be sensitive to temperature, as long as the output
> remains two times the input. This means, while the internal
> values may change with constant frequency, the output remains
> two times the input. No calibration needed.
>
> > I have found a cheap chip (maybe $1 or less) for the basic function.
> > I won't say what the chip is.
>
> Well that info might save some searching time, living here in Silicon Valley
> I have found many chips to be made out of unatainum anyway. That's one
> reason I am a dormant electronics hobbyist. Note the reference to a
> thirty year old data book.
>
> >The level of integration is probably
> > not high enough to meet the price point. I would need a voltage
> > regulator, an external buffer transistor, a couple caps for filtering
> > the regulated power and so on. This is making the solution a bit
> > on the large side, and the voltage regulator could be more expensive
> > than the doubler chip :)
>
> Not a good project to try and make money. Too many conditions.
>
> a) User must have an Intel CPU that produces too much heat.
> Intel will fix this or have already done so. Short time period.
>
> b) A "Zalman CNPS7700 AlCu CPU cooler" must be installed and
> be able to cool the CPU with low fan speed.
> I wonder if this occurs with any other CPU Heatsink / fan products.
>
> c) User must be building a low noise PC like a HTPC.
> This is being done more and more. A home built PC or upgrade
> being done by the user. A small number of people.
>
> The best solution would be to put more money in Zalman's pocket,
> not yours. They may have possibilities of reporting the fan speed
> two times the actual speed that the fan is rotating much cheaper.
>
> Perhaps in the future the BIOS and probe programs will have
> the ability to set the lower limits. And the upper limits for Probe.
> The high end fixed at 6000 is also a problem as you can not
> see small changes.
>
> The front panel will take a long time to include this capability
> and the time that BIOS and Probe can be changed also may be long.
>
> Start sending your cards and letters to ASUS and Zalman.
>
> Zalman I suspect will be first to respond putting a little more circuits in
> their Fanmate 3 or higher.
>
> Selling the Fanmate 3 to existing customers might cover the development
> costs for Zalman.
>
> > <<snip description of optical tachometer>>
>
> That sounds like a good and cheap idea and one that I did not think about.
>
> Power Supply fan speed would be able to be monitored for the older PS
> that do not have a monitoring connection.

I'm afraid this project will have to remain a hobbyist fantasy.
There are many ways to solve this problem, and whoever tries
to commercialize it, will not be getting rich any time soon.

If might be better to build a complete fan monitor and control
center, and incorporate the feature in there. Even that market
is poorly served (which should tell you how much of a business
opportunity it is), and the issue is how do you make money doing
it. At least with a product like that, a direct-web-sales approach
might be possible. For cheap electronics, the distributor and
retailers eat all the profit, and even if you have extremely
high volumes, you are still "eating Kraft Dinner".

If the brushless DC fan motor had more drive phases on it,
that would give more pulses per revolution. It would also
raise the price of the fan motor. Building an optical tacho
into the hub of the motor, would not require the sync detection
method of the Sanyo module, and painting a contrasting pattern
inside the hub will give you whatever pulse rate you want. Cost
is a LED, some resistors, and a darlington phototransistor.
Same as the design I used to measure the RPMs on my central
air condenser fan.

Paul
 

Butch

Distinguished
Apr 1, 2004
20
0
18,510
0
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

On Sun, 14 Aug 2005 13:34:35 -0400, nospam@needed.com (Paul) wrote:

>In article <vRDLe.5623$WD.1459@newsread1.news.pas.earthlink.net>, "Stephen
>H. Fischer" <sfischer1@mindspring.com> wrote:
cut cut
>>
>> That sounds like a good and cheap idea and one that I did not think about.
>>
>> Power Supply fan speed would be able to be monitored for the older PS
>> that do not have a monitoring connection.
>
>I'm afraid this project will have to remain a hobbyist fantasy.
>There are many ways to solve this problem, and whoever tries
>to commercialize it, will not be getting rich any time soon.
>
>If might be better to build a complete fan monitor and control
>center, and incorporate the feature in there. Even that market
>is poorly served (which should tell you how much of a business
>opportunity it is), and the issue is how do you make money doing
>it. At least with a product like that, a direct-web-sales approach
>might be possible. For cheap electronics, the distributor and
>retailers eat all the profit, and even if you have extremely
>high volumes, you are still "eating Kraft Dinner".
>
>If the brushless DC fan motor had more drive phases on it,
>that would give more pulses per revolution. It would also
>raise the price of the fan motor. Building an optical tacho
>into the hub of the motor, would not require the sync detection
>method of the Sanyo module, and painting a contrasting pattern
>inside the hub will give you whatever pulse rate you want. Cost
>is a LED, some resistors, and a darlington phototransistor.
>Same as the design I used to measure the RPMs on my central
>air condenser fan.
>
> Paul
Out of interest i opened up a three wire fan to see how the speed
sensor works.
Below the motor there is an IC (with 4 connectings wires, i believe a
Hall effect sensor) a transitor and two resistors and a capacitor.
On the IC is printed "276 fB4". Looking at the internet i could not
find a specific datasheet of this IC.
Also i could not deduce the function of the transistor but i believe
its function is either voltage stabilazation (input voltage fluctuates
depending on speed setting) or an amplifier/emitter follower for the
output.

Has anybody more information on the IC?

Ofcource you can increase the sensors output frequency with some fancy
circuitry. But it is maybe easier just to put a second Hall effect |C
(180 degrees opposite) in the fan and put the two circuits in
parallel (assuming the output is an open collector).

Anybody any suggestions or comments?

Butch
 

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