PC Fan Simulation

[daVinci2793]

I would like to respectfully request the addition of a PC Fan simulation.

To be specific, I would love to see the standard 3-pin and 4-pin 12v 120mm PC fan added. These usually come with a tachometer and PWM control signal.

Here is a white paper from Noctua describing the PWM specification and tachometer functionality.

I know this is potentially a complicated request, but I love Wokwi and have thus far found it to be easily the best free Arduino Simulator (and for that matter better than all the paid simulators I have tried.) I really appreciate the whole project and plan on using your simulator for teaching and learning for the foreseeable future.

[urish]

Thanks for the information!

Here are the important bits from the datasheet:

PWM Input

Target frequency: 25kHz, acceptable range 21kHz to 28kHz Allowed duty-cycle range 0% to 100% The signal is not inverted, 100% PWM duty cycle (= 5V DC) results in maximum fan speed. The fans operate at full rated speed if there is no PWM input signal.

The fan‘s speed scales broadly linear with the duty-cycle of the PWM signal between maximum speed at 100% PWM and the specified minimum speed at 20% PWM (see www.noctua.at for individual fan specifications): For example, the NF-A12x25 PWM has a maximum speed of 2000rpm and a minimum PWM speed of 450rpm, so it will run at 2000rpm at 100% PWM, 450rpm at 20% PWM and around 1100rpm at 50% PWM. Operation below 20% PWM duty-cycle is not officially supported in the Intel specification (undefined behaviour). However, most Noctua PWM fans can be operated at below 20% and will stop at 0% duty-cycle. Only the following models keep running at their specified minimum speed when the input is below 20%: NF-A20 PWM, NF-S12B redux 1200 PWM and NF-B9 redux 1600 PWM

RPM Speed Signal

Therefore, the formula for obtaining correct RPM speed is: fan speed [rpm] = frequency [Hz] × 60 ÷ 2

[daVinci2793]

Yeah, that is about all of the useful information I personally gleaned from those documents. Thank you for the response!

[urish]

Do you have some ideas how to implement the visual part of the PC Fan?

[daVinci2793]

Well, I have my two cents, but it definitely doesn't need to be anything fancy. Probably just a simple "rotating fan" animation with a direction and speed indicator. Just something that gives a decent visual feedback without being overly complicated. The most important part of this addition would be properly simulating all the inputs/outputs which aren't strictly unique to PC Fans.

[yepher]

In case it helps I drew this PC Fan in case it can help. To animate just change id="pc_fan_cvs-fan" rotate to 0-360 degrees. I can probably do better on spacing of the fan blades if it triggers anyone OCD.

pc_fan.svg

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    <!-- Generated by PaintCode - http://www.paintcodeapp.com -->
    <g id="pc_fan_cvs-fan_page">
        <g id="pc_fan_cvs-frame">
            <rect id="pc_fan_cvs-rectangle2" stroke="rgb(22, 22, 22)" stroke-width="12" stroke-miterlimit="10" fill="rgb(22, 22, 22)" x="0" y="0" width="288" height="288" />
            <circle id="pc_fan_cvs-oval2" stroke="rgb(151, 151, 151)" stroke-width="1" stroke-miterlimit="10" fill="rgb(255, 255, 255)" cx="143.5" cy="144.5" r="137.5" />
        </g>
        <g id="pc_fan_cvs-fan" transform="translate(144, 144) rotate(-124)" >
            <ellipse id="pc_fan_cvs-fan_hub" stroke="rgb(151, 151, 151)" stroke-width="1" stroke-miterlimit="10" fill="rgb(22, 22, 22)" cx="0" cy="0.5" rx="44" ry="40.5" />
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Here is a demo of it in action: