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Cass-Ole

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July 5th, 2015 05:00

Aurora R4 Windows 10 Upgrade Success Command Center 3.5.10 & AlienFx

10Fx.JPG

edit 11/21/15:

My post here has been edited; it began as an Insider Preview thread last summer, but today I upgraded W7 to W10 successfully & have a working CmndCntr. As always before a Windows install, I unplug my Master I/O board;s usb connector - install Windows (this time as an upgrade to 10) - and when my install/upgrade is done I plug the mio usb connector back in; Windows will detect the MIO as a usb device & install the drivers for it. I was running CC3.5 on W7, so CC came along for the ride as part of the upgrade process; after I plugged the MIO usb cable back in, booted up, CmndCntr was pre-installed & took over duty as normal. I have the option of using CC3.6 if 3.5 spazzes out with 10, but so far so good.

I did not experience the dreaded 100% systems fans at startup after the 10 upgrade

Visit Dell.com's Aurora R4 driver page for all of your newer W10 driver needs

System Fans @ 100%?

{edit: see this post: two users have reported a 'cure', one, using the jumper reset method, & two, installing CmndCntr using Windows 7 or 8 Compatibility Mode - which is a suggestion I made - but which no one has verified as a cure until now.}

edit: posted by JasperY

"The problem with Command Center (Thermal Controller and Alien FX) is that windows 10 disables the service that helps detecting hardware monitoring. You need to reactivate it in the "Services". Go to Services, and set "Windows Sensor Monitoring Service" to active, and startup mode to "Automatic". It should fix it".

Many users since July 29 have had 10 do some voodoo on their system, where fans are/were running at 100% at startup. I avoided that somehow, but do not know how or why, and it is possible my system will be stricken later with this issue, who knows.

I'm using the top of my post here to archive threads regarding 100% fans in Aurora & Area-51; whatever info I had as to possible cures & fixes has been posted in them & I've nothing more to add until my own fans go to 100% where I can troubleshoot it hands-on. The 1st thing to try is an uninstall/reinstall of CmndCntr, followed by going into Thermals & setting manual control, set the fans 'low' (start at 10% etc & see how your Alien responds). The correct procedure to uninstall CmndCntr is found later below:

archive of issues related to models using a master i/o board on W10

R4's have 5 CmndCntr versions to play with, all should install on the R4 mthrbrd 'without issue':

W10 > 'turn windows features on/off' > turn on .net3.5, it might help regardless the CC version

at the very bottom of this page I've posted 'stuff', a project idea to mechanically reduce fan speed by using either a dedicated fan controller (NZXT Sentry Mesh or similar) or just an in-line resistor of the correct value, similar to the photo below (sold as fan speed noise blocker or similar); the pre-assembled speed-blocker resistor u see in the photo below is a bit whimpy & is meant for low-power fans of about 0.5amps or less so we can't use that on our hi-power stock fans.

Keep in mind that one strategy is to start by replacing the stock hi-power (1amp - 1.5amp) 4pin Delta fans & replace them with low-power 4pin fans rated at 0.5amps or less in combination with a pre-built speed-blocker or hand-made blocker (project) as I've posted at bottom of page:

fan speed - Copy.jpg

 fans @ 100% on start-up --> your 1st lines of defense / things I would try <--

  • power dissipation 'reset' > if no good:
  • uninstall / reinstall CmndCntr > if no good:
  • perhaps uninstall CmndCntr 1st > do a jumper reset > reinstall CmndCntr
  • some users report that entering CmndCntr Thermals menu, set fan control to manual > set fans to 5%-10%, restart & leave the setting or gradually increase % setting as you look to restore normal operation
  • if you have your own method that fixed your fans, post them in this thread or create your own

Note: never install CmndCntr from the Resource DVD or the MIO board will probably 'brick' / 'ruined'. Always get your CmndCntr download from your Dell.com drivers/apps page:

Alienware Desktops MIO (Master Input/Output) Troubleshooting & Policy

Correct procedure to reinstall Command Center on Area-51 and Aurora systems

1. Uninstall Command Center from the Control Panel > Programs and Features.

2. Open My Computer, click Folder and Search Options, choose the View Tab and enable Show hidden files and folders. Click OK.

3. Go to C:/Program Data/Alienware/Command Center/Thermal Controls and delete the Profile.xml file.

4. Go to C:/Users/ /AppData/Local/Alienware/Alienware AlienFX/Themes and delete all *.ath files.

5. Verify that the device manager doesn't have any unknown devices under Universial Serial Bus Controllers. If there are unknown devices see note

6. Restart the computer.

7. Download the latest version of Command Center available and run it.

8. Complete the Alien Command Center installation by answer Yes to all dialogue pop-ups. During the installation process, the Master I/O board firmware will be updated. Do not shut down the computer at this time. If the firmware update process fails, please contact Alienware for support.

9. Restart the computer.

10. Verify that there are no Unknown devices under Universal serial Bus Controllers. If there are unknown devices see the note below.

11. Launch Command Center

Note: If there are unknown devices on the device manager, or no device is detected please do the following: a. Verify the Master I/O board USB cable is properly connected to the motherboard and to the Master I/O board. b. Drain the MB power for 1 minute.

guide below was created & posted by an owner who doesn't mind editing the registry; if editing the registry makes you want to faint, skip step #3:

"The steps below may not be necessary but I like to make sure all the junk from left over programs is completely removed.

1. Uninstall Command Center via control panel -Programs and Features-(do not reboot when asked).

1A. Go to C:\ProgramData\Alienware and delete Alienware folder (if it is there)

1B. Go to C:\Users\xxxYour Account Name Folderxxx\Appdata\local\Alienware (delete AW folder if it is there)

1C. Go to C:\Users\xxxYourAccount Name Folderxxx\Appdata\roaming\Alienware (delete AW folder if it is there)

2. Download and Run CCleaner's registry cleaner to remove left over keys from the old Command Center uninstall. { http://www.piriform.com/ccleaner }

3. Open Regedit (Winkey + R...Type Regedit), press control + F. In find what type Alienware and make sure the keys, data, and value is checked and click find next. After deleting each object (key, value, or data) related to Alienware press F3 to find the next Alienware location and delete. Repeat until done. DO NOT DELETE ANYTHING IN THE SYSTEM INFORMATION FOLDER WHEN YOU GET THERE.

4. Download and install the latest AW Command Center from Dell's website. Search by your service tag. Then reboot when prompted

My Summer Time Insider Preview Post

Moving on, below is a Summer post on the success I had on the  W10 Preview ... there may be useful tips & links in this post related to 10 that you're welcome to look over as well. If you don't get answers on this forum you can also try to post on www.AlienwareArena.com/forums ...

ohhh say can u see, by the dawn's early light ...

red (1).JPG

I'm pleased to report that my baby knight fury Toothless has declared his independance from win7 & is happily flyyyyying up up & away with the latest W10 Preview build 10162:

DESK - Copy.PNG

and AlienFx is along for the ride:

8623.snip.PNG

{as of July 16 I'm on the latest / last 10240 build without issue}

To help make W10 a reality, I used Acronis disk-cloning software to image / move my every-day-use W7 install onto a different hard-drive; from there, instead of doing a clean install, I 'upgraded' W7 to W10 & kept all my files/software, namely the Cmnd Cntr. On the flip-side, my original W7 install is kept alive & well on its own drive for safe-keeping & in working order. The key here is to make sure you do not erase your original W7/8 install, & do your W10 clean install or upgrade on a separate drive, or use similar safe-guards relative to your original 7/8 image (imaged onto dvd's / external hdd etc).

5722.PTDC0005.JPG

With my system off, I unplug the master i/o board's usb connector; by doing this, I'll ensure the mio stays out of the data-loop while W10 installs. From Tesla's Post:

MIO-Board Notes: I have installed and re-installed Windows on my Aurora many times and never had a problem. However, some users have had problems with their MIO-Boards (they get locked up) after clean installing Windows (they weren't using this guide, and might have done other things incorrectly, but still ... it warrants caution I suppose). Therefore, I have added the additional steps to dis-connect the MIO-Board from the motherboard while Windows is installed and setup for the first time. While this step is likely un-neccessary, it's one way to side-step any potential issues. (Added 3-2-2012)

7888.PTDC0004.JPG

with mio usb disconnected, power-on, AlienFx will revert to white led's up-top, an indication the mio has power but isn't communicating with the mthrbrd, which is what I want:

3438.PTDC0010.JPG

after W10 installs, I'll power-down, reconnect mio usb, power-up:

1881.PTDC0012.JPG

system displays all red led's - a good sign - & CC should act as normal, which eventually it does ...

To begin the upgrade process, with my mio usb disconnected, I boot into W7, mount my W10 ISO in my dvd tray, then click on setup; I'm online when this happens, W10 looks for & snatches some updates then begins to install itself over W7; after about 40 minutes the install's complete. Once my initial W10 desktop appears, I power-down, reconnect mio usb, power-up, & this is what happens:

  • AlienFx / case lights all revert back to red, a good sign
  • but oops: the pci-e fan is loud now & spins fast, hmmmm
  • I launch CmndCntr & I can change AienFx colors
  • but in Thermal Controls I get tell-tale signs it isn't working: system fan = 0%, no manual control over hard drive or pci-e fan etc

Not sure what to make of it, so I hit 'restart':

  • pc restarts
  • I hear the pci-e fan simmer down
  • from there the CmndCntr reverts back to normal
  • odd but true, & it was probably a mio initial driver install + restart issue

Now I have full control, CC & AlienFx go back to theIr normal working condition as if nothing were amiss. By upgrading from W7 to W10 & having the Cmnd Cntr carry-over & come along for the ride, I do not have to reinstall CC, it is in-place once W10 installs & eventually works which is what I was after.

Disconnecting the mio usb before any type of a Windows install is advice that's been used for several years now which is why I followed that advice, it works. In the past we disconnected the mio usb so that the mio wouldn't 'go off-line' during the install & be troublesome getting it up & working again after the install, so the advice is to disconnect it & by-pass the issue itself. If you upgrade from W7/8 to W10 & do not disconnect your mio usb 1st, I don't know how or if it will affect your CmndCntr or mio, nor do I know if it is always necessary to disconnect 1st prior to your upgrade/install or to leave it alone, nor will I attempt leaving it connected to 'find out what happens' during some different reinstall, since I'm not up for more wear & tear on my pricey system. Disconnecting it 1st had no undesirable affect here other than needing a restart in order to restore normal operation & I'm satisfied the procedure & the advice itself 'works'.

I won't be doing a clean install of W10 on my R4 anytime soon. Since CmndCntr / AlienFx is the priority software issue to worry about, there will be a real debate in the coming weeks over whether the best method is:

  • a clean W10 install followed by a new CmndCntr install
  • upgrading to W10 directly form your W7/8 install & allowing CC to carry-over
  • whether both methods will work eqwally well & there are no issues to worry about
  • whether disconnecting or leaving the mio usb in place are eqwally tried & true methods

For now, if you try a clean Preview install followed by a CmndCntr install & you have issues, you can start-over & use this method, which hopefully does the trick. Having done a clean W10 Preview install on my Area-51 R1 a few months ago, I do not see any problems with Aurora either, but who knows.

All of my core system drivers (chipset / network / audio / video / usb) were present either because they carried over from W7 or because W10 installed them itself, or a little of both, but I did not have to install drivers afterwards nor did my device manager show any issues. Lovely.

I do not use Win8/8.1, & so do not have 8/8.1 info. I'm running the earlier CmndCntr version 3.5.10, not the latest CmndCntr 3.6.5, & do not know how that version behaves with W10 Preview. What I can say is that if you 'upgrade' your W7/8 to W10, your CC will in the least carry-over & at the most may even work ... & hopefully you'll have the same success & issue-free install as I did.

Since this is an experimental version of Windows, I can not Know yet if the very next W10 update will make CmndCntr crash or mis-behave, but, for now it works & hopefully this remains true when the real-deal launches in 24 days.

Win10 How-To, Related Info Tips & Help

10 Tips before installing the latest Windows 10 build:

Latest W10 ISO: http://windows.microsoft.com/en-us/windows/preview-iso-update?os=win10

Do a build to build upgrade using Windows 10 ISO file:

How to install the latest Windows 10 build:

Do a clean install of Windows 10:

Do a custom installation of Windows:

Microsoft Community Help:

My other Win10 Preview forum posts:

  • upgrade to Windows 10 July 29 for free
  • [DEAD LINK /owners-club/alienware/f/3746/t/19639047]http://en.community.dell.com/owners-club/alienware/f/3746/t/19639047

(for advice w/your Area-51 R1 & Aurora):

Help >Forum Post > Windows 10 Aurora R4 Fans

 "Hello everyone, this is my first post here, Just wanting to let you know, when you upgrade to windows 10 ( in my case the insider verison) Your PCI fan and your Hard drive fans Will go full song all the way up to 100%. After several Days of looking into this, which about drove me crazy, I saw a post about this issue only it was for windows 8.1 and a Alienware Command Center issue. The Resolution for this happening on windows 8.1 worked for me if you are having the Fans issue. The resolution that worked for me is as follows.

Download the most up to date version of Command Center for windows 8.1 (3.5)

Uninstall the old version with a program such as IO Bit Uninstaller, this is to make sure you get all of the registry entries off before installing the newer version. then once the uninstall and the registry edits are made, reboot the machine. Now, once you are back to your desktop, install the newest version of Command Center, once again when it completes, reboot the machine. And TADA no more fan noise! ( at least for me). I hope this helps someone if they are having this issue, or will have this issue if you decide to get windows 10 on your Aurora R4".

My note: I have qwestions about the scenario which led to full-speed fans that couldn't be fixed on day one. It says 'uninstall the old version', which was what old version? What was version 3.5 being upgraded over? In otherwords, what older version didn't work on win10? At any rate, 3.5/3.6 are the last versions. If you read in my notes above, when you upgrade to W10 & carry-over your CC(the version you have that works right now) - if it doesn't work for you after your W10 upgrade, try the advice given above, which reduces to 'uninstall older / reinstall newer CC version'.

edit: 7/19 Aurora R4, W10 & BIOS version A11

I was contacted by a fellow Grey here at Starfleet with an urgent message:

  • 'reserved W10 upgrade / Aurora R4 / predict my upgrade should have no problems / my only worry is the BIOS / still running A09 / your thread didn't mention what BIOS you're on / long story short: should my BIOS be completely up-to-date (version A11) to ensure w10 upgrade with no major issues on my R4? I'm a bit scared to flash the bios

The answer is I don't know. The answer is, flashing your BIOS is always a risky venture. It may be too late to try the W10 Preview for a test-drive, in this instance as a pre-release window into how A09 behaves on the preview. My answer is, upgrade to W10 on its own hard drive / SSD & try it with A09. If no good? Wait for others input here, make a post describing the issues, see what people think. Flashing up to A11 to me is a last resort.

There is Aurora BIOS information scattered everywhere on the forum during the past few years, it isn't consolidated in any single thread, but here is a post I made with links, you'll have to sift through the old forum threads & do a simple search such as 'Aurora BIOS' & go where the results take you:

Tesla1856 is our resident Aurora & BIOS guru. Take care to sift through the threads he created and took part in which described how to perform a BIOS update & how to possibly recover from a BIOS update gone wrong (a bricked / dead motherboard).

There were people who tried to jump from A02 directly to A11 & failed because it was best thought to move to newer BIOS versions in incremental jumps (A02 >A05 > A07 > A11 for instance). My mthrbrd is running A11 because I bought it that way; I too would be paranoid if it'd had an earlier version, arrived here with A09 & if so I would probably still be on it, for fear of bricking which Aurora's developed a reputation for over the years. When in doubt about moving up to A11, do yourself a favor & make a forum post 1st, asking for the best way to handle it, as special steps may be reqwired (flashing your BIOS outside of Windows) with a higher probability of success than inside of Windows (?)

Repository of Aurora BIOS versions:

Project Idea / Last Resort: Fan Controller or In-Line Resistor to Reduce Fan Speed

I'm posting this info here so I can store it for myself for later use possibly but you're welcome to browse the info I've collected below (I'm thinking out loud to myself here, listen in if you prefer). Years ago I bought a fan of some sort that had a 'speed reducer' adaptor which is nothing more than a resistor soldered in-line to the red / positive 12volt-wire in heatshrink; the resistor helps reduce fan speed:

2133.PTDC0001.JPG

this is similar to a pre-built item found online:

fan speed - Copy.jpg

Note that a pre-built kit like the one above is probably designed for a low-power fan; in reality our high-power system fans would probably need 3 or 4 of those SAME resistors (in-series) in order to safely work. photo shows the project idea only, chances are you can not buy what u need & have to make it

If worse comes to worse, in order to stop high-speed 100% fans at start-up in my Aliens due to a Windows 10 glitch relative to CmndCntr software & the mio board I can either install a basic fan controller like an Nzxt Sentry Mesh or similar (our system fans are 4pin pwm-types such that the Sentry Mesh & most other brands will use a 3pin fan connector & aren't exactly compatible out-of-box with our 4pin fans & would need a mod due to it)(if you shop for a fan controller you can look for those which accept 4pin pwm fans) ... from there I'd set my fans to manual control adjusting dials & such, or I can make my own harness like the photos above:

1323.reo2.jpg

SentryMesh & other fan controllers typically come eqwipped w/3pin fan connectors. to me it's as simple as buying new empty 4pin connectors - taking the 3pins off - putting new 4pins on it instead:

ele-946 - Copy.jpg

http://www.frozencpu.com/products/14300/ele-946/FrozenCPU_31-pin_Male_PWM_Shielded_Fan_Connector_-_Black_.html?tl=g51c387s1555

4p 3p.jpg

http://www.ebay.com/itm/4Pin-PWM-Male-to-3Pin-Female-Adapter-Cable-Black-sleeved-CB-PWM-3F-/271136606286?hash=item3f2100484e

- someone else might look into a simple 4pin-to-3pin adaptor -

- or install new 3pin fans into your system which is pricey perhaps but a certain possibility -

Moving onto a resistor project, note our system fans are typically high-powered at a current of 1amp (Aurora hard drive & pci-e fans) to as much as 1.4a to 1.5a (Aurora rad-fan)(Area-51 R1 rad & pci-e fans) & would need a more robust resistor than you saw in the photos earlier. An exact resistor value needed can be divined using basic math & algebra using formulas. Below I've dug up a pair of articles you can browse.

I haven't done the math yet on 1amp & 1.5amp fans; the info below is a strict copy/paste; later if I have to I'll do the math on possible resistor specs based on higher-power 1amp / 1.5amp fans. Resistors that can dissipate the higher heat generated by 1a/1.5a fans would be needed than what the articles describe. Browse over the info & work out the math for yourself if you plan to make your own in-line fan-speed reducer. I won't be fielding any questions on 'how-to make one', ok? Look at the info & decide what to do with it. If the day comes & I need to make my own speed-reducer-kit I will post my results & the resistor types / values I used. Also note that any 'store-bought' pre-assembled speed reducers are probably a bad idea & probably only work on low-power fans of 0.5amps or less. When in doubt, message the vendor & ask if the harness is rated for a 1amp or greater fan. If not, do not buy it.

Reducing Fan Speeds: http://www.blackfiveservices.co.uk/fanspeed.shtml

"... a safer option for slowing down a fan is to place a resistor in series with the fan.
In this way, you can achieve any voltage drop you like, provided you don't mind doing some heavy math to get there. Here's how we would calculate the resistor value required to run a fan at 7V from a 12V power source, dropping the voltage by 5V. So to achieve a voltage drop of 5V, we would need a resistor with value of 42 Ohms, and capable of dissipating 0.6W of power. This highlights one potential pitfall of this method - you can't safely use 1/4W resistors for this, unless you make up the target resistance using several smaller resistors (of equal value) in series..."

Scenario Below: 12Volt DC Fan rated @ 0.2amp

*** Note that a project like this may be a FIRE HAZARD ***

ohms law.JPG

using this chart, a person can plug-in values for a 1amp & 1.4a / 1.5a system fan & learn the correct resistor values to purchase or use in a fan-speed-reduction project. Below I've plugged-in some values off the top of my head, like a 1.5amp fan that I wish to slow-down by running at 9volts (not 12volts). The probable resistor I need to drop the voltage & handle the current can be found at the bottom:

Rated Fan voltage: 12V
Rated Fan current: 1.5A
V = I x R  (Ohm's Law) --> 12v = 1.5a x R --> R = 12v / 1.5a = 8ohm
Rated Fan resistance = 8 Ohms
Target voltage: 9V
V = IR --> 9v = 8 x I --> I = 9v / 8ohm = 1.125amps (3 d.p. / three decimal places)
Target current: 1.125A
Voltage drop across resistor: 12v - 9v = 3v
V = IR --> 3v = 8ohm x R --> R = 3v / 1.125a = 2.67
Target resistance: 2.67 Ohms
Power dissipated by resistor (Volts x Amps = Watts) 3v x 1.125a = 3.375Watts

{ As an example, I can now look for a 5watt resistor of approx. 2.5 - 3ohms to do the trick }

5O5W - Copy.jpg

immediate choices are 3ohm 5watt military or ceramic; a stop into RadioShack might provide a different assortment to choose from for testing fan speeds

*note* a resistor can be useful to drop a fan's speed but it will also get hot, perhaps very hot in the process, so be careful & don't catch your pc on fire or death & destruction may result. Normally a resistor which is too weak in your wiring scheme to handle the current will invariably burn-up. That's why when the chart called for a resistor of 3.375w, I would choose a beefier 5watt rated resistor.

Modifying PSU Fans from 12v to 9v: http://www.tomshardware.com/forum/342276-28-modifying-fans

{Scenario Below: 12v Dc Fan rated @ 0.12amp}

"I'm guessing you calculated thus: R = V/I = 9/0.12 = 75 Ohms. Wrong. That answer is close to the effective "resistance" of one fan motor IF it continued to draw 0.12 A when supplied with only 9 V (and it would not). It's actually a good number NOT to use.

First, to reduce 12 VDC down to 9 V, you need the drop across the resistor to be 3 volts, not 9. Next, the current flowing in the circuit. If I read your post right, EACH fan claims to draw 0.12 A, and there are two of them in parallel. If you are planning on one resistor in the line that is shared by the two fans, then the total current is 0.24 A when they have the full 12 VDC supplied. However, you propose to give them less voltage, so the current will be lower.

So, let's work with the total resistance and see where we get. Apparently each motor behaves as if it were a resistance of R = V/I = 12/0.12 = 100 Ohms, so two in parallel is like 50 Ohms. You want to add a second resistance of R in series with that, so the the voltage split is 9 V across the 50 ohms, and 3 volts across the R. Thus R is 16.67 ohms. Don't know where you can get one of those, but you might get one at 20 ohms. This would make its drop a little over 3 V, and the motors would get 8.57 V, not 9. If you did that, the current in the line would be I = V/R = 12/70 = 0.17 A, and each motor would be running on about 8.57 V with a current of 0.085 A. However, that all assumes that the motors continue to act like pure resistances, which is not true. At lower speeds the probably offer slightly less "resistance" and the real values in operation are harder to predict.

For resistor power rating, P = I^2*R = 0.17*0.17*20 = 0.58 Watts. A 1 Watt will do. However, 2 Watts is a good idea, considering the impact of starting currents.

You should be aware that, for a few seconds at start-up, a motor will pull a current of 2 to 3 times its running current because its impedance is very low when nearly stalled. In your proposed circuit, the effective "resistance" of the two motors in parallel during start-up is more like 16 to 25 ohms, not 50, and thus the voltage drop across the resistor you plan is greater - perhaps 6 V - leaving only 6 V drop across the motors to start them up. This is getting close to the minimum necessary to start the motors, and they might NOT start up this way. And even if they do when you first put this together, in two years when the motor bearings start to wear and their friction is higher, the motors will need MORE starting voltage. but won't get it. So you may be setting up a failure, now or in future. Consider how the mobo controls case and CPU fans when it is set to do so "automatically". Of course, its control system is more complicated than a simple resistor, but it does accomplish fan speed control by varying the voltage supplied to them (at least, that's how 3-pin fans work). If you observe closely, though, you will see that most of these systems work by applying the full 12 VDC to the fan for a few seconds at start-up. Then the control system takes over and reduces the voltage AFTER the fan is already running at full speed. A simple series resistor can't do that.

I can understand that you believe your other fans already provide a significant air flow into the case and through, and hence probably also through the PSU, so that the full speed of these two fans is not needed. But you don't know that, and you really have no way of testing whether some components inside your PSU are overheating. So doing what you plan is taking a risk with no way to check it yourself.

Not quite - the problem is that with only 9 V across the motor, it won't draw the same current of 0.12 A. Do it with the resistances, where you don't need the amperage.

Motor "resistance" = RM ("Resistance" of Motor) = 12/0.12 = 100 ohms

Add a resistor R in series so that voltage drops are 9 V across 100 ohms (I know, at slower speeds the motor's impedance will not be 100 ohms, but it's approximate) and 3 volts across R. Then R must be 100/3 = 33 ohms. Now you can estimate the current as I = 12/133 = 0.090 A, and the resistor power dissipation as P = 3*3/33 = 0.272 Watts.

So you need approximately a 33 ohm, 1/2 Watt (or 1 Watt) resistor for each motor's hot lead." ----

Note: the above discussions can be used to help choose the right resistor values

Note: look online to find other articles & discussions related to resistors & fan-speed-reduction

https://www.google.com/#q=DC+fan+speed+resistor

 

 

 

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