Fan tastic fan

[Epbowen]

It finally arrived...gaads! It's huge! There goes my roof. I knew it was 14 in but it really didn't sink in until I got the thing. Now, since my trailer is 4x9, I need to slow the thing down. I saw a post on instructables where the guy use an lm34 current controller. Any one else try that setup with a pot for speed control. I know it'll burn some extra juice, but from what I've read going the pwm route can make the even noisier in a small space. So, thoughts and suggestions??

[MtnDon]

I have one of these as a speed control. It operates at 15kHz which with the state of my hearing puts it in my "can't hear a thing" zone.

[Epbowen]

MtnDon, yeah my hearing is shot at some freqs. The wife on the other hand hears great. I plugged a usb charger into our power outlet and she could hear it...me not a thing.

[48Rob]

Don,

I see it has a small heat sink.
Does it run "hot" as a result of reducing the current?

Rob

[Shadow Catcher]

A pulse width modulation controller (I used one to do a test on LED's) less power consumption.

[Epbowen]

I got the lm317, a 15k ohm pot and some resistors. Made the voltage controller and tried it out on the fan. It works well on settings 1 and 2. Setting 3 draws too much current for this device. I ended up putting 550 ohm resistor for the divider instead of the 270, this gave me almost full use of the pot for speed control. From dead stop to 1.5 amps it works great... I did put the lm317 on a heat sink, it was warm after about 30 min at full current. Not too hot to touch, warm. So for $6 and change at radshak it's worth a try.

[jonw]

I replaced the 3 speed switch on mine with one of these from Amazon:
http://www.amazon.com/gp/product/B0087ZCFP8/ref=oh_details_o09_s00_i00?ie=UTF8&psc=1

Works great. You will need to get a new knob from the hardware store for it..

[Epbowen]

Ordered the pwm....the reg circuit just ran too hot! So, just put the fan in and will live with too much fan until the pwm comes in.