Search found 56 matches

by trident
Fri Mar 30, 2012 5:35 am
Forum: SPCR Article Discussion
Topic: Seasonic SS-350TGM 80 Plus Gold TFX
Replies: 48
Views: 31435

Re: Seasonic SS-350TGM 80 Plus Gold TFX

North America Availability :( I have been looking for a retail vender in the U.S.A. with little success. Received a reply from Stella Lo at SeaSonic Electronics that the SS-350TGM is not currently in stock at SeaSonic California warehouse, only available as a sample from HQ in Taiwan. The SS-300GTW ...
by trident
Fri Mar 02, 2012 8:03 am
Forum: Fans and Control
Topic: Reconciling soft-mounting and fan grills?
Replies: 9
Views: 2259

Re: Reconciling soft-mounting and fan grills?

I used the blue "EAR" grommets and 6/32 screws to decouple an exhaust fan on this pc7, but must take care with the compression of the grommets.
Image
by trident
Tue Apr 05, 2011 9:23 pm
Forum: Fans and Control
Topic: Technical collaboration: PWM to linear fan control
Replies: 8
Views: 1822

Re: Technical collaboration: PWM to linear fan control

the PCB would be way cooler if you used SMDs and made it small enough to hard-mount on the fan header :) (just sticking 1" off the header) I did a PC board with Eagle using 1206 chip resistors and a FMB3946 {a 2N3904 + 2N3906 in an SSOT6 package} and it was only about 30% smaller. To get a signific...
by trident
Tue Apr 05, 2011 5:13 am
Forum: Fans and Control
Topic: Technical collaboration: PWM to linear fan control
Replies: 8
Views: 1822

Re: Technical collaboration: PWM to linear fan control

You did not say where the the two capacitors were in the circuit, so I'm guessing they are the input and output caps for the 7805. From your description this is the circuit: pm.stacker_BJT.png If this is the correct circuit, then the BC337 is directly applying the PWM signal to the fan. As the duty ...
by trident
Sat Apr 02, 2011 7:41 pm
Forum: Fans and Control
Topic: Technical collaboration: PWM to linear fan control
Replies: 8
Views: 1822

Re: Technical collaboration: PWM to linear fan control

U1 is a TL431, Q1 is a PNP emitter follower, Q2 is a NPN emitter follower, Q3 is p channel FET. The current sourced from the base of Q1 is mirrored to the collector of Q2. The voltage drop across R4 drives the gate of Q3. Simulating with LTspice the output at 100% PWM is 11.9V into 60 ohms. Have a l...
by trident
Sat Apr 02, 2011 1:27 pm
Forum: Fans and Control
Topic: Technical collaboration: PWM to linear fan control
Replies: 8
Views: 1822

Re: Technical collaboration: PWM to linear fan control

Looks great pm.stacker.
Is the LED a voltage reference or for "bling"?
by trident
Fri Apr 01, 2011 7:56 am
Forum: Fans and Control
Topic: Technical collaboration: PWM to linear fan control
Replies: 8
Views: 1822

Technical collaboration: PWM to linear fan control

Looking to build a PWM to linear bridge that is small enough to reside on a 120mm fan.
Would like to brainstorm with like minded folks about circuits and PC board design.
It would be helpful if you understand in LTspice and Eagle.
Any one interested?
by trident
Sun Mar 06, 2011 7:08 am
Forum: Fans and Control
Topic: The 4-pin PWM fan specification document
Replies: 26
Views: 57182

Re: The 4-pin PWM fan specification document

sthayashi

Would you be interested in collaborating?
Been working on a circuit with LTspice that has a P-channel FET for the output.
Would post, but ".asc" files are not currently allowed in this forum.

Regards
by trident
Fri Sep 10, 2010 7:12 pm
Forum: Fans and Control
Topic: In need of 2-pin headers: where to buy them?
Replies: 9
Views: 1776

That is likely a XH connector housing. It is a 2.5mm pitch connector produced by several Asian vendors. Digikey sources them from JST. The two position housing [XHP-2] is digikey part number 455-2266-ND Tin plated crimp terminals, 22-28AWG for that housing are [SXH-001T-P0.6] digikey part number 455...
by trident
Tue May 25, 2010 5:38 pm
Forum: SPCR Article Discussion
Topic: Fan Test System, 2010
Replies: 89
Views: 31109

Great article Mike, very informative. I have a question. As you stated in the article, thermal systems (heat source, heat-sink and fan) are very difficult to model. As an example: heat-sink 'X' may out perform heat-sink 'Y' with a 137W input, but the reverse can happen at a different heat input. Thi...
by trident
Sun Apr 25, 2010 9:15 pm
Forum: Fans and Control
Topic: PWM 4-pin to 3-pin conversion, electrical advice wanted!
Replies: 9
Views: 6573

It would be more involved than just moving the transistor. That circuit is using the PWM signal to turn the transistor on and off, so it would still corrupt the Tach signal. Not familiar with the adapter you linked to or if it's any good. You could build something like this and it would be about the...
by trident
Sun Apr 25, 2010 4:42 pm
Forum: Fans and Control
Topic: PWM 4-pin to 3-pin conversion, electrical advice wanted!
Replies: 9
Views: 6573

To have the RPM sensor (Tach) work, the ground wire of the fan needs to be hooked directly to ground. The circuit in your post has the transistor between the fan ground and power ground, not so good for the Tach signal. What range of voltage do you want for the fan? Would say 5V to 11V be OK? How sm...
by trident
Sat Apr 17, 2010 6:48 pm
Forum: CPU Cooling
Topic: Difference between 3 pin and four pin fan?
Replies: 9
Views: 1581

PWM is digital and gives power to the fan in pulses. In essence it turns the fan on and off very rapidly. It is very power efficient, but as with may things there are trade-offs. Some motherboards with the 4-pin fan CPU fan header only support 4-wire fans, so if you plug in a 3-wire fan you have no ...
by trident
Mon Apr 05, 2010 7:16 pm
Forum: Fans and Control
Topic: Which PWM, CPU or Specialty Fan do you Want SPCR to Review?
Replies: 50
Views: 23452

Voted other, would like a review of 92mm and 120mm
Scythe Gentle Typhoons
by trident
Thu Mar 25, 2010 8:08 pm
Forum: Fans and Control
Topic: Control Apple Mac Pro 4 wire fans (not PWM though)
Replies: 7
Views: 9248

As a starting point: Try a low pass filter and emitter follower buffer. I'm at a disadvantage, not knowing the input impedance of the control pin on your Delta fans. If the input impedance is ~10K this may be all that's required.
by trident
Mon Mar 08, 2010 12:05 am
Forum: Power Supplies
Topic: anyone have a dead 120mm fan psu to donate?
Replies: 3
Views: 1183

Have an ANTEC TPII-380 shell. Has the original fan, line cord connector and the bushing for the output cables. Is missing the on/off switch and the 115V/230V switch. The guts went to e-waste recycling some time ago. PM if interested.
by trident
Sun Mar 07, 2010 11:32 pm
Forum: General Gallery
Topic: Diffrent Laptop HDD mod for NSK3400/3300
Replies: 2
Views: 2627

Taking a page from BTX airflow. I am thinking the M/B is less likely to have a dead air zone with a fan pushing air over it, because the rotating flow from the fan outlet tends to stir-up the air column more than a fan pulling air over the M/B. Don't know if it will work. The NSK3300 has plenty of e...
by trident
Sat Mar 06, 2010 12:06 pm
Forum: General Gallery
Topic: Diffrent Laptop HDD mod for NSK3400/3300
Replies: 2
Views: 2627

Diffrent Laptop HDD mod for NSK3400/3300

http://s3.postimage.org/dJjSS.jpg http://s1.postimage.org/tUIor.jpg http://s4.postimage.org/cLIfJ.jpg New holes in bottom of chassis and tray modded for laptop HDD. M3, 8mm long by 5mm hex male/female standoffs are used to secure the HDD with the original grommets. http://s2.postimage.org/tkXAJ.jpg...
by trident
Wed Dec 16, 2009 6:17 pm
Forum: Fans and Control
Topic: Speed fan error in controlling fan speed
Replies: 1
Views: 4288

rivet Your best source for troubleshooting info would be the support section of the SpeedFan Home Page . On the face of it, could be that a device is accessing the SMBus at the same time that SpeedFan is loading. Try disabling SMbus access for SpeedFan. Select the "Configure" button, open the "Optio...
by trident
Fri Nov 27, 2009 12:57 pm
Forum: Power Supplies
Topic: NSK3480 - EarthWatts 380 - PSU Fan Swap
Replies: 3
Views: 1629

nemo For the EA-380, I suggest a fan that starts reliably at 4 volts, otherwise the fan won't start ruining until the PSU heats up a bit. Several posts in the general gallery have used the Noctua NF-R8. I used an Adda AD0812MB-A71GL, salvaged from a NeoHe that suffered an early demise, with good res...
by trident
Mon Nov 23, 2009 9:11 am
Forum: Fans and Control
Topic: PWM to Voltage bridge
Replies: 43
Views: 35845

Shaggy My apologies, I did not consider the graphics card could be using low side drive. If this is the case, using the divider, the signal would be 180° out of phase. That is 12 volts @ 0% duty cycle and 3.3 volts @ 100% duty cycle. If you use differential sensing, low side drive won't be an issue...
by trident
Sun Nov 22, 2009 8:20 pm
Forum: Fans and Control
Topic: PWM to Voltage bridge
Replies: 43
Views: 35845

Shaggy
You are correct, the MAXIM circuit was designed for a 3.3 volt PWM signal, however you could add a voltage divider configured to divide buy 3.6 (100k and 39K) to scale the 12 volt signal to a 3.3 volt signal.
_______
trident
by trident
Sat Nov 21, 2009 9:36 pm
Forum: Fans and Control
Topic: PWM to Voltage bridge
Replies: 43
Views: 35845

Shaggy Your question doesn't have enough information for a definitive answer. What do you mean by low frequency and 2-pin? I am going to guess that you have a controller that outputs high current (500 to 1000mA) PWM that is capable of directly powering a typical fan. If this is the case you may want...
by trident
Mon Nov 16, 2009 2:14 pm
Forum: Fans and Control
Topic: Custom microcontroller fan controller - work in progress
Replies: 19
Views: 10952

Useful information about controlling fan speed. Maxim AN1784.pdf I do not wish to start an argument or claim there is only one best way to go. I offer this as another option. There are many ways to convert PWM to linear voltage, your design goals determine the best method for your application. If yo...
by trident
Mon Nov 16, 2009 6:51 am
Forum: Fans and Control
Topic: Custom microcontroller fan controller - work in progress
Replies: 19
Views: 10952

Greetings Hypernova The 2 amp limitation is because of the three pin fan connector {reference Molex 22-01-3037 and 80-50-0114}, with tin over brass contacts 2.5 amps is the max. current handling. Reviewing your project goals, "No more than 1V drop from the control circuits, range should be 5~11V", u...
by trident
Fri Nov 13, 2009 11:45 am
Forum: Fans and Control
Topic: PWM to Voltage bridge
Replies: 43
Views: 35845

Working on revised circuit, MOSFET selection not as critical(main requirements are Rds(on) @Vgs=10V: <100m Ohm and Vgss >12V). edit 18 Apr 2010: Experimenting with fixed integrator. The variable integrator has proven to be non-linear, due to a large difference in the charge and discharge currents an...
by trident
Sat Oct 03, 2009 11:01 am
Forum: General Gallery
Topic: PC-7 Updraft HDD cooling
Replies: 6
Views: 4310

Greetings ctrler, welcome to SPCR!
What part of the chassis would you like to see in the new pictures?
_______
trident
by trident
Wed Sep 09, 2009 6:14 pm
Forum: Power Supplies
Topic: Low watt PSU with modular design? Rec'd ones are modular
Replies: 18
Views: 3345

Greetings There is a caveat to soldering in modern PSUs in that many if not all use lead free solder and it is best not to mix legacy tin/lead solder with the current tin/copper alloys. 96SC (SAC387) which also contains silver is a good lead free rework solder, however it is quite expensive. In my l...
by trident
Mon Sep 07, 2009 1:56 pm
Forum: Fans and Control
Topic: Thoughts on a fan controller I have been tinkering with
Replies: 19
Views: 4978

Greetings mcmahad and EsaT Analog control will dissipate the excess voltage as heat, but the waste heat may not be as large as you may think. A brushless fan behaves similar to a fixed resistor, so the the current draw of the fan decreases with applied voltage. For a 12 volt fan with 0.3 amp running...
by trident
Tue Jul 14, 2009 2:33 pm
Forum: General Gallery
Topic: PC-7 Updraft HDD cooling
Replies: 6
Views: 4310

Things are progressing slowly as the current economic downturn is directly affecting me, have more time, but much less money. Modifications completed to date: Close front fan port with 3.2mm ABS sheet overlaid with AcoustiPack Add PC-60 HDD rack with suspension bungees and soft mounted updraft fan C...