Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: BANE on September 30, 2010, 05:48:24 PM

Title: computer rpm signal wire?
Post by: BANE on September 30, 2010, 05:48:24 PM

Hello all,
I'm currently working on my hacked power chair's motor controller and happened to include 2 80mm fans (probably overkill, but cool looking) to it.  http://www.xoxide.com/thunderblade4.html (http://www.xoxide.com/thunderblade4.html)
My question how and what can i control with the rpm wire?  I'm assuming i can control the fan's speed. it is serial or pwm?  
thnx,
bane

Title: Re: computer rpm signal wire?
Post by: Soeren on September 30, 2010, 07:37:35 PM

Hi,

Quote from: BANE on September 30, 2010, 05:48:24 PM

My question how and what can i control with the rpm wire?

Nada.
It's a sense wire that is used to measure the speed of the fan (the page actually tells you so).
You can control it by either a varying voltage or PWM on the positive wire and then get feedback from the sense wire, to make a closed loop.

And yes... Humongous overkill  ;D

Title: Re: computer rpm signal wire?
Post by: madsci1016 on October 01, 2010, 11:53:52 AM

Quote from: BANE on September 30, 2010, 05:48:24 PM

what can i control with the rpm wire?  

A fan fail alarm. Something that will just buzz or even shut down the controller if a fan fails.

Title: Re: computer rpm signal wire?
Post by: BANE on October 01, 2010, 04:05:07 PM

thnx, i'm just going to control both fans with a relay so i'll just cut that wire off.   Just out of curiosity, the signal form of the signal wire?  is it Analog? I/O? Serial?

bane

Title: Re: computer rpm signal wire?
Post by: BANE on October 01, 2010, 05:45:25 PM

just in case anyone wants to see the power chair's motor controller unit :)    Has a 70amp 24v relay between the sabertooth2x25/circuitry and batteries controlled by the landing gear toggle on my heli RC controller.  I decided to install this e-stop feature after loosing control of this robot and having it crush a hole in the wall.