The most popular protocol by far is a 25 kHz PWM signal to change fan speed. All you have to do is send a square wave at this frequency to the fan, and the duty cycle will determine the fan speed. That is precisely what the circuit below will do . The control input is usually an open-drain or open-collector output with a 5 V or 3.3 V pull-up. The PWM control signals are square waves of high frequency, usually 25kHz or above, to make the noise from the fan above the audible human range
The PWM fan controllers have many advantages against other rpm fan controllers. Yet, they tend to be difficult in construction when high frequency is required. The PWM controllers usually generate acoustic noises, when the PWM frequency is within the acoustic spectrum (20Hz to 20KHz). A high frequency PWM controller usually operates above the 20KHz, thus the human ear cannot hear this sound. Moreover, PWM controllers can achieve very stable and low speeds without the possibility of a fan stall These fans take a PWM signal on their 4th pin to control the speed of the fan, from the spec's of the fan it says it requires/expects: The following requirements are measured at the PWM (control) pin of the fan cable connector: PWM Frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to 28 kHz Maximum voltage for logic low: VIL = 0.8 V Absolute maximum current sourced: Imax = 5 mA (short circuit. also die Amplitude wird bei PWM logischerweise immer gleich bleiben und ich denke mal das wird wohl 12V sein. In welchem Frequenzbereich die PWM agiert kann ich dir aber leider auch nicht genau. .formfactors.org/developer\specs\REV1_2_Public.pdf. This is much faster than the usual Arduino PWM frequency of around 600Hz. I reprogrammed one of the counter/timer registers to generate a 25kHz PWM signal PWM-Lüfter arbeiten in einem Bereich um die 25 kHz, welches bedeutet, dass ein kompletter Zyklus (ein und aus) 25.000 mal in der Sekunde abläuft. Nebengeräusche können zwar entstehen, sind..
Example schematic for a single 12V fan: PWM control. This is the tricky part. The specs require a PWM signal with a frequency of 25 kHz (with tolerance, 21-28 kHz), but our usual analogWrite function doesn't output anywhere near that frequency. By using some timer tricks, we can make it generate 3 PWM signals at the correct frequency. I'll show you the code first and then explain it AW: PWM LÃ¼fter ohne PC betreiben. So hab viele Infos durch den Hersteller bekommen. Hier ein paar Infos bezüglich dem PWM Signal laut Richtlinie: Frequenz: 25kHz normal, 21-28kHz sind akzeptabel (mein Lüfter liegt bei 18-30kHz) Maximale Spannung: 5,25V (Soll aber bei max. 5V liegen Intel specification (July 2004, Rev 1.2) defines the intended operation of a fan that implements the Pulse Width Modulation (PWM) control signal on the 4-wire fan interface. The following requirements are measured at the PWM (control) pin of the fan cable connector: PWM frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to 28 kH But you can't set different frequencies for pins that are controlled by the same prescaler (e.g. pins 6 and 5 must be at the same frequency). If you use the default values set by the Arduino Diecimila's bootloader, these are your PWM frequencies: Arduino Pins 5 and 6: 1kHz. Arduino Pins 9, 10, 11, and 3: 500Hz Hello, any chance of controlling the speed of 4 PIN computer fan directly from ESP8266 (Wemos D1)? According to the PWM specification, the signal should have: PWM Frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to..
Well, almost all fans die if the voltage is lowered under 5V, but with PWM control, the fans can reach really low operation speeds of 300-600 RPM. They don't die literally; they just shut down and stop spinning, and that is why often the declared speed range of the fan can only be achieved by using PWM regulation. At these speeds, the fans are dead silent, and some fans can even be turned off completely via PWM regulation. One more very cool thing about PWM regulation is. Pulse-width modulation (PWM) is a common method of controlling computer fans. A PWM-capable fan is usually connected to a 4-pin connector (pinout: Ground, +12 V, sense, control). The sense pin is used to relay the rotation speed of the fan and the control pin is an open-drain or open-collector output, which requires a pull-up to 5 V or 3.3 V in the fan. Unlike linear voltage regulation, where the fan voltage is proportional to the speed, the fan is driven with a constant supply. From the standpoints of acoustic noise, reliability, and power efficiency, the most preferable method of fan control is the use of high-frequency (>20 kHz) PWM drive. Besides eliminating the need for noisy pulse stretching and the commutation noise associated with low-frequency PWM, it has a much wider control range than linear control. With high- frequency PWM, the fan can be run at speeds as low as 10% of full speed, while the same fan may only run at a minimum of 50% of full speed using. Zum Einbau der PC-Buchse (Molex) musste die Platine etwas aufgebohrt werden. Der Mikrocontroller arbeitet mit der integrierten (ggf. nicht sonderlich stabilen) Frequenz von 8 MHz. PWM erfolgt nur via Software. Die Standard-PWM-Frequenz von 25 kHz ist mit geringer Auflösung (0-10) möglich, fiept aber Just wondering, what PWM frequency is this running at? I couldn't work out from your code, but I read that the default PWM freq for the Arduino using analogWrite is 980Hz, much too low to be out of audible range. Do you think it would be quiet if I ran an n-channel mosfet using PWM at over 25kHz, even with the capacitors/resistors omitted
Pwm Pc Fan Controller Circuit. by Saum Hadi Posted on November 6, 2018. High frequency pwm fan controller attiny85 based temperature dependent fan controller ics protect and enhance arduino pwm fan controller pwm fan controller bit tech. Circuit Converts Pwm Fan Drive To Li And Reduces Acoustic Noise. Pwm Fan Controller Bit Tech . So You Want Pwm Control Of Your New Cpu Fan Techpowerup Forums. The PWM switching frequency has to be high enough not to affect the load, which is to say that the resultant waveform perceived by the load must be as smooth as possible. The rate (or frequency) at which the power supply must switch can vary greatly depending on load and application Die Frage, ob sich ein PWM-Lüfter lohnt, ist mit einem klaren Jein zu beantworten, denn wie so oft, gilt auch hieres kommt drauf an. Wenn du deinen PC vergleichsweise stark beanspruchst und/oder viele Stunden pro Tag daran zubringst, lohnt sich eine solche Investition schon allein aus rein finanziellen Gesichtspunkten. Schließlich ist die Energieeinsparung über einen langen Zeitraum. About this project. I have been wondering about this project and how to control my 4 pin PWM fans. I had 5 laying around and thought mine as well give it a shot. The frequency values can be adjusted between 125 HZ -- 8 MHZ as well as a variable duty cycle. The circuit utilizes the mode 10 PWM phase-correct on timer 1 OCR1A (Pin 9) and ICR1 (Pin.
It is very simple to set up a PWM signal at any frequency you desire, with any resolution you desire, provided you don't exceed the maximum 'bandwidth': the frequency multplied by the resolution must be less than half the clock speed of the device. The full explanation with relation to the ESP-IDF is available here Blue : PWM input; Yellow : Tacho output (Frequency Generator) Red : DC 5V; Black : Ground; Package contents: 1 x 92x92mm Cooling Fan (DC 5V) 8 x M5 PC Fan Screws . Related products Wishlist. Quick View. Cables USB3.0AM L type to Micro USB Cable $ 2.00. Add to cart. Wishlist. Quick View. Out of stock. Memories 128GB eMMC Module H2 $ 45.00. Read more. Wishlist. Quick View. Out of stock. Cases. Re: PWM speed control frequency of modern 4 wire computer fans? « Reply #3 on: January 11, 2021, 10:08:05 am » Doctorandus_P described the situation as it was some 15 years ago Next, head over to the Advanced tab. Make sure manual mode is selected for all PWM controlled fans. Set a minimum and maximum spinning speed for the fans in the Speeds tab. Next, go to the Fan Control tab and set up a temperature curve for each fan. This is extremely important because it helps you monitor the effect your changes will have. After all of this is done and you've saved the. fan speed [rpm] = frequency [Hz] × 60 ÷ 2 The calculation for the above example waveform is: 86 [Hz] ÷ 2 × 60 = 2580 [rpm] If the fan rotor is locked, the tachometer output signal will remain either at high or low depending on the position of the rotor. Noctua PWM specifications white paper Designed in Austria, Noctua's premium cooling components are internationally renowned for their.
AN-CM-248 PWM Controller for PC Fans.gp, GreenPAK Design File, Dialog Semiconductor GreenPAK Development Tools, GreenPAK This application can be used to adjust the frequency of each fan with I 2 C commands that are generated by the application. Figure 19. C# Application GUI The application pings all 16 I 2 C addresses once per second and populates the GUI with the slave addresses that are. Closed Loop high frequency PWM PC Fan Controller. This circuit is the natural evolution of the previous High Frequency PWM Fan Controller and the PIC 3-Wire Fan RPM Controller. In a first glance, the circuit appears to control the duty cycle of high frequency PWM pulses with a potentiometer. Yet this is not the actual operation of this circuit «PWM» est un terme issu de l'ingénierie électrique, c'est l'abréviation de «Pulse Width Modulation», parfois traduit en français par «modulation de largeur d'impulsion». En bref, dans notre cas, il s'agit du fait que vous pouvez utiliser le PWM pour paramétrer la vitesse de rotation d'un ventilateur comme bon vous semble The fan clips fit any 120mm fan so a PWM replacement is feasible. Some of my gamer family members had X58 systems during the 2008/9 period, and they used the Noctua NH-C14 with just one 120mm PWM fan on the top and found it perfectly OK. The contemporary PWM fan of choice was the Akasa Apache which had a 600 to 1600 speed spec, but typically would idle using the Asus BIOS Silent Profile in the. In the case of PWM-driven fans, most PWM drivers produce common mode noise at high frequency reaching into the MHz range. Inductive motors driven with PWM can induce common-mode noise in nearby circuits through the power lines as conducted EMI, which may affect your EMC rating. This type of fan driving is more common in computers that require speed control. Note that this also requires the use.
PC-Lüfter über PWM ansteuern führte zu Rauchentwicklung Anzeige. Hallo alle. Ich habe für einen Aufbau extra die PWM Frequenz so hoch gesezt (10kHz), dass ich mit einer kleinen Spule eine einstellbare Gleichspannung erzeugen konnte mit der der Lüfter dann wie gewünscht lief. Nachdem ich dann die relativ hohe PWM Frequenz vor Ort nich so leicht erzeugen konnte habe ich in. I will demonstrate the use of transistors by controlling PC fans from a computer's LPT (parallel) port. Then I will implement a simple form of PWM (pulse-width modulation) to control the fan's speed. This demonstrates the ability of transistors to use low-voltage, low-current signal lines (such as a parallel port or microcontroller IO line) to control higher voltage, higher current devices.
If the frequency of the PWM signal is too slow, the fan's speed will noticeably oscillate within PWM cycle resulting in undesirable fan noise. The frequency can be also too high. But PWMing the fan and therefore the internal commutation electronics too quickly can cause the internal commutation electronics to cease functioning properly. Remember these electronics were designed to run on. I recently had the need to control the RPMs of a 4-wire fan (like these used in PC cooling), so here is a simple schematic that does it. It is based on the 555 integrated circuit, connected in astable configuration. In the following: 3 and 4-wire fans; 555 25 kHz PWM schematic; How does it work. 3 and 4-wire fans In PC cooling you can find 2-wires, 3-wires and 4-wires fans. In 99.9% of the. FanController/FanController.cpp Line 55 in 785590a analogWrite(_pwmPin, 2.55 * _pwmDutyCycle); I love the way you architected this class. Seriously very nice. And I.
The PWM frequency is just 1/T where T is the period of each cycle. You can set the frequency to any value you want depending on what you're trying to control. We'll dig deeper into this in future tutorials, but for now, we'd like to dim an LED. So a PWM frequency of 1kHz will be good enough for this application. The last PWM parameter, the Resolution is a measure for how many discrete. Just testing at the moment but I have a standard PC PWM fan, runs from a minimum of approx 30% to 100%. I have connected the PWM wire to pin 9 (&10 &3) of a UNO, then a 12v power supply to the fan positive and the negative to the ground on the UNO as well as the fan. So far so good, fan sppeds up to maximum then down to min and stays there. SO then I tried both of the PWM options inside sketch. SmartFusion cSoC: DC Fan Control Using PWM 4 3-Wire Fan The 3-wire fan has three pins: power, ground, and tachometer. This fan can be controlled either by varying the DC voltage or by using the low frequency PWM drive signal. The 3-wire fan has a tacho signal, which indicates the speed of the fan. Based on the tachometer readings, you can.
level 1. Sen0rClean. · 4m. I've done something similar using a Sonoff SV running Tasmota to turn the fan on and off, and also generate the PWM signal. It generally worked well - the only thing is that the PWM on the ESP8266 is software, so it can only generate fairly low frequency pulses (adjustable - 4kHz max) where PC fans usually specify 20kHz The PWM frequency is 25KHz nominal, with an allowed range of 21-28KHz. Lots of other info here. The main thing is, the fan itself has to contain some smarts. No 3-pin fan can be made into a 4-pin PWM fan by one of us ham-handed DIYers. Evidently, the 4-pin smarts include defaulting to full-on when no pin-4 control signal is present, which accounts for the observed behavior. (I googled 4 pin. PWM fan-speed controller to adjust the speed of up to two cooling fans, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases. Speed control is accomplished by tachometer feedback from the fan, so that the speed of the fan is controlled, not just the PWM duty cycle. Accuracy of speed measurement is ±4%. The MAX6639 is.
Scenario: I want to control a PC fan using the Raspberry Pi. The 4-wire-fan (MGT9212UR-W25) has its own power supply (12V) and can be controled via PWM. I would like to control it with a Python script using the RPi.GPIO module, which unfortunately leads to bad results with a loud creaking noise. The fan's PWM input is connected to the Raspberry Pi on pin 12 (BCM) In a PC * The PWM control from the motherboard will have no effect on the fan speed. In a DIY Project. Controlling the Fan. In a PC. In the mainboard BIOS, you can activate and configure the PWM fan speed. Please refer to your mainboard manual regarding the settings in your BIOS. Some mainboard may able to adjust the fan speed in manual mode to customize according to your own preference. Fan. (BIG PROMO) US $2.55 18% OFF | Buy 12V PWM Voltage Regulator DC Motor Temperature Speed Controller Regulator Fan LED Light Dimmer Control Switch 4 Wires From Merchant CZB6721960 Store. Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. Shop Quality & Best Motor Controller Directly From China Motor Controller Suppliers
The PWM frequency (or width) to the fan's motor. itself could be completely different then the PWM frequency the motherboard is switching at. When the board calls for 50% fan. speed, it sets the PWM duty cycle to 50%. The actual motor's speed in the fan is seldom linearly proportionate to duty cycle This articles documents how to build a 12V PC fan PWM controller with Dialog GreenPAK configurable mixed-signal ICs. The project involves rotary encoding, PWM control, PCB design, and C# application programming. The design can control up to 16 3-pin computer fans, uses a pair of Dialog GreenPAK configurable mixed-signal ICs to control each fan's duty cycle, and includes two ways to change. The route might be different for you. Make sure you're using absolute path. The '&' symbol means this script runs in background. If you don't want to know the theory part, than go ahead to: Reading RPM Signal PWM uses square wave's duty-cycle to reduce the average value of voltage, if the duty cycle is 50%, the fan will spin at 50% of it's full speed; duty cycle 75%, fan 75%, and. Aqua Computer Forum » Weitere Foren » English forum » Multiswitch PWM - what period/frequency? etoel. Junior Member. Beiträge: 38. Multiswitch PWM - what period/frequency? Freitag, 4. April 2008, 12:01. 1; Since hooking up normal fans to the pwm outputs on the multiswitch is not such a good idea I started to look into how pwm based fans work. Most motherboard use a 4 pin header on the CPU. with low noise and reduced fan frequency disturbance. This performance fan has several unconventional fan design approaches that can greatly dissipate heat efficiently and quietly. 4-PIN PWM DESIGN XPG has teamed-up with Nidec, improving the original GentleTyphoon design to provide a tailored solution for modders and PC absolute best. Pulse Width Modulation (PWM) allows motherboards to alter.
PWM Frequency. A frequency or period is specific to controlling a particular servo. Typically, a servo motor anticipates an update every 20 ms with a pulse between 1 ms and 2 ms. This equates to a duty cycle of 5% to 10% at 50 Hz. Now, if the pulse is at 1.5 ms, the servo motor will be at 90-degrees, at 1 ms, 0-degrees, and at 2 ms, 180 degrees. By using PWM we can feed the DC motor with different voltages, based on a duty cycle and on a PWM clock frequency. We must remember that a DC motor needs some current to run. Our digital device can output, say, either 0V or 5V, but with a low current. In order to drive a real fan, some additional circuitry is needed. This circuitry will, most likely, change the 5V output into a 12V output and. The PWM signal generators adjust the WIDTH of the signal (how much it's on vs off). The second one listed allows frequency adjustment, which is what you need. Run it off of 5v only and hook the output to the fan signal header. You may need to play with the settings to get the right minimum frequency. Jul 12, 2016
Well, you can also change or control fan speeds manually but the process is a bit tricky. You need to connect a manual fan controller to your Windows system with knobs and this will set fans to different speeds.. So, it is best to go for the automatic option via software to control the computer's fan speed. The automatic PC fan speed controller software monitors temperatures from numerous. Fan Speed not matching Curve Controller (30. November 2020, 14:33) English forum » Parts for Aquaero 6 (Fan Output Chip) (26. Dezember 2013, 08:13) English forum » Aquaero 5 PWM output frequency change (17. Januar 2013, 23:15) English forum » Output on PowerAdjust not working (14. März 2012, 14:22) Wasserkühlung » Wakü Neuling!! Was. This 140mm PWM quiet fan can be used as a PC case fan or on heatsinks and liquid cooling radiators. Airflow and static pressure figures for this fan stand at 59.5 CFM and 1.08 mm H2O respectively. This silent fan is a fine product of German engineering and is one of the best silent 140mm fans out in the market. Yes, it is a bit on the expensive side but is totally worth it Frequency spectrum of the Arctic P12 PWM as case fan. Let's next look at the frequency analyses of all measurements for all fans measured and all three speeds tested in the process. The graphs speak for themselves: 500 rpm 1000 rpm 1800 rp High Frequency Pwm Fan Controller. Fan Controller Ics Protect And Enhance Electronic S . Controlling 3 Pin Fans Or Water Pump Using 4 Pwm Control From Mobo Techpowerup Forums. Why And How To Control Fan Sd For Cooling Electronic Equipment Og Devices. Hw 585 Pc Cpu Fan Sd Controller. Hw 585 Pc Cpu Fan Sd Controller. So You Want Pwm Control Of Your 3 Pin Fan Techpowerup Forums. 4 Wire Pc Fan. So.
Variable Frequency PWM Arduino . In this example, we will control the output frequency of waveform between 10 Hz and 100 Hz at pin 9 with the help of a potentiometer at Analog Pin A0. Calculate Required Frequency for PWM. The following formula determines the value be entered in the register ICR1 for a particular frequency It is now time to configure our pwm fan controller's analog to digital converter (which is built into the Launchpad RM57L MCU). Go to the ADC1 tab and set the FiFo size to 1, as that's all we'll need for this project. Also select Enable Pin 7, as that is what we will connect the temperature sensor to.Pin 7 is marked 'AI1_7' on the underside of your Launchpad development kit It spins fine at all frequencies,including slowest speed, when connected to a separate desktop PWM fan controller. However, when using above-mentioned commands to turn fan on at full speed (255 out of 255), it will only stutter and fails to start spinning. IF pushed along with a toothpick, it starts up and spins fine. I have tried breaking it in by running it on nano at full speed, as. Sie sind an der richtigen Stelle für pc fan pwm high. Mittlerweile wissen Sie bereits, was Sie auch suchen, Sie werden es auf AliExpress sicher finden. Wir haben buchstäblich Tausende von großartigen Produkten in allen Produktkategorien. Egal, ob Sie nach hochwertigen Etiketten oder günstigen, kostengünstigen Großeinkäufen suchen, wir garantieren Ihnen, dass es sich hier auf Aliexpress.
Servo motors and fan speed control (you may notice that case fans for a computer will sometimes be rated as with PWM) are two common implementations of PWM. New technology such as what is found in. PWM technique can be easily defined in terms of duty cycle and the frequency it takes to repeat the duty cycle per second. The duty cycle highlights the amount time the signal switches between ON and OFF position. It is described in percentage. If the signal remains ON half of the total duty cycle and remains OFF in another half, then the duty cycle will be 50% That combined with the default suggested range of 100 gives a PWM frequency of 100Hz. You can lower the range to get a higher frequency, at the expense of resolution, or increase to get more resolution, but that will lower the frequency. If you change the pulse-width in the driver code, then be aware that at delays of less than 100μS wiringPi does it in a software loop, which means that CPU. Enabling FAST_PWM_FAN results in unstable serial communication for SKR 1.4 turbo (LPC1769) and 250000 baud. Tested back and forth with different cables and could reproduce instantly. Bug could also be related to wire-routing or board-routing. I did not test other baud rates. My Configurations. Configuration_adv.h // Increase the FAN PWM frequency. Removes the PWM noise but increases heating in.
In addition, the fan propeller is meticulously designed to reduce the disturbing frequency fan noise to a more refined vibration tone better suited to human ears. In addition with the 4 anti-vibration rubber pads, XPG VENTO PRO 120 PWM operates at mere 28dB(A) even at its maximum fan speed of 2,150 RPM (100% duty cycle) ASUS ROG Strix XF120 Whisper-quiet PWM Fan, 1800rpm. Optimal blend of airflow and static pressure: Enables use as a PC case, radiator or CPU cooler fan. MagLev bearing: Stabilizes rotor for reduced friction and noise, and offers 400,000-hour life span. Minimized acoustic profile: Whisper-quiet, 22.5 dB (A) cooling performance and tuned to. (190-Hz Electrical Frequency = 5700 RPM) Figure 7. Drive Currents of Competitor Device With Sinusoidal BEMF Motor (190-Hz Electrical Frequency = 5700 RPM) The human audible hearing range is 20 Hz to 20 KHz. Cooling fans inside of laptops, notebooks, an
To avoid acoustic-noise problems, the minimum PWM frequency is set above 23 kHz. This green-mode function enables the power supply to meet international power conservation requirements, such as Energy Star®. With the internal high-voltage startup circuitry, the power loss caused by bleeding resistors is also eliminated. To further reduce power consumption, FAN6605 uses the BiCMOS process. Lesen Sie pwm pc fan Erfahrungsberichte und pwm pc fan Bewertungen - Kaufen Sie pwm pc fan mit Vertrauen auf AliExpress Die Pulsdauermodulation - kurz PDM (englisch pulse duration modulation); auch Pulslängenmodulation (PLM), Pulsbreitenmodulation (PBM), Pulsweitenmodulation (PWM; abgelehnt in IEC 60050, auch englisch) und Unterschwingungsverfahren genannt - ist eine Modulationsart, bei der eine technische Größe (z. B. elektrische Spannung) zwischen zwei Werten wechselt I replaced the rear intake and the 2 HDD fans with 2 of these NF-S12A PWM fans and my computer is now silent even under load. It's amazing that I'm running this beast of a PC and it's completely silent. The Noctuas have a much improved motor and PWM IC design, so they have no commutation noise. PWM fans usually have this ticking sound, no so these ones. While I could live with the commutation.
ARCTIC F12 PWM PST - 120 mm PWM PST Gehäuselüfter, Case Fan mit Standardgehäuse, PST-Anschluss (PWM Sharing Technology), Reguliert RPM synchron, 230-1350 U/min., AFACO-120P0-GBA01, Schwarz - Kostenloser Versand ab 29€. Jetzt bei Amazon.de bestellen Arctic PC fan F 8 PWM PST CO 8 cm. Perfect blower control with PWM The PWM-function is signalled via the motherboard exactly to determine the speed of the fan running. This guarantees a maximum cooling performance at minimum noise level. Patented PWM sharing technology (PST) reduces the noise leve
How To Auto Control Your Pc S Fans For Cool Quiet Operation Fan controller ics protect and enhance electronic products circuit converts pwm fan drive to linear and reduces acoustic noise high frequency pwm fan controller high frequency pwm fan controller. Whats people lookup in this blog: 4 Pin Pwm Fan Controller Ic; About author. Sante Blog . Add a comment . No comments so far. Be first to. PCのPWMファンには規格があるので、まずはそれを押さえる。 PWM Frequency: Target frequency 25 kHz, acceptable operational range 21 kHz to 28 kHz; Absolute maximum voltage level: VMax = 5.25 V (open circuit voltage) PWMの周波数は、目標値は25kHzだけど、21-28kの範囲まで許容する。この辺の値は. •PWM Controller signal, this device can simultaneously drive a fan, •PWM Frequency: 10Hz to 40kHz monitor remote sensor diode temperatures, and Duty Cycle: 0% to 100%, 8 Bits measure and control the fan speed so that it operates •Automatic Fan Speed Control Loops with minimal acoustic noise at the lowest possible speed. •SMBus Interface •Power: 2.7V to 5.5V The AMC6821 has three fan.