Help Science Fair.....

[Ppulot]

Hello yes, I'm trying to build a wind tunnel for science fair and I'm trying to find a way to change the rpm of fans without having to basically build a computer. Is there a way to do that, or do I have to trust myself with soldering electronic components. 

[emosun]

use a potentiometer fan controller

[imreloadin]

3 minutes ago, Ppulot said:

Hello yes, I'm trying to build a wind tunnel for science fair and I'm trying to find a way to change the rpm of fans without having to basically build a computer. Is there a way to do that, or do I have to trust myself with soldering electronic components. 

Something like this would work:

 

https://www.amazon.com/Computer-Chassis-Controller-Supply-Interface/dp/B07PYFRJ2S/ref=pd_day0_201_20?_encoding=UTF8&pd_rd_i=B07PYFRJ2S&pd_rd_r=5527db49-34d2-4d34-94b5-63cae0cc86df&pd_rd_w=4Kera&pd_rd_wg=uoKJ5&pf_rd_p=d495c3b6-b08c-488d-b587-92006fef8456&pf_rd_r=D46D0TJ5F43S2VEQS0XG&psc=1&refRID=D46D0TJ5F43S2VEQS0XG

 

You'll need a power supply though

[artuc]

Do you need to incorporate circuit design, soldering and assembly or programming into the project or are you looking for whatever just works ?

 

If electronics design, go with a pot on a FET or transistor driving a standard DC fan

 

For programming, go with a microcontroller or single board computer and use a PWM fan.

 

Otherwise an off the shelf solution.

[JustTheTip]

How much experience do you have with soldering etc?

[kelvinhall05]

17 hours ago, JustTheTip said:

How much experience do you have with soldering etc?

He doesn't need much experience, it's an extremely basic circuit, 4-6 joints max.

Spoiler

This should work.

[JustTheTip]

20 minutes ago, kelvinhall05 said:

He doesn't need much experience, it's an extremely basic circuit, 4-6 joints max.

  Hide contents

This should work.

Very true, was just checking as I have seen plenty of people scuff even the simplest of circuits during my undergrad ahaha. That said a quick YT tutorial and anyone can do it 

[mariushm]

Get an adjustable linear regulator like LM317 and make the circuit on a prototyping board or whatever ... besides the 3 pin chip, it's just a potentiometer and a resistor. 

 

The datasheet contains example circuit : https://www.ti.com/lit/ds/symlink/lm317.pdf

 

I simplified the example schematic from page 11 below : 

 

 

So basically a resistor, a potentiometer, 2 capacitors and optionally a generic diode. 

 

 

[ColinLTT]

3 hours ago, mariushm said:

Get an adjustable linear regulator like LM317 and make the circuit on a prototyping board or whatever ... besides the 3 pin chip, it's just a potentiometer and a resistor. 

 

The datasheet contains example circuit : https://www.ti.com/lit/ds/symlink/lm317.pdf

 

I simplified the example schematic from page 11 below : 

 

 

So basically a resistor, a potentiometer, 2 capacitors and optionally a generic diode. 

 

 

Not that this wouldnt work, but I think you should do some math on how much flow your tunnel will need before you decide on PC fans - the bigger the tunnel cross-sectionally the higher CFM you will need to move to attain the air velocity you need. If you can avoid building a circuit, I would, because if I were to show off a wind tunnel I would want to focus on what the tunnel can achieve/the science you can produce, not a breadboard that controls the thing, but ymmv. 

 

Don't forget to account for some extra length to accommodate a flow straightener - a bundle of plastic straws works well for this. Alternatively you can get honeycomb cardboard from some specialty vendors.