This job ad has been posted over 90 days ago...

Contract Circuit design / programming

at (Anywhere)


I’ve got a small project for someone, and I would like to see who is up to the challenge. I’ve got a small data center, and I’ve seen our cooling costs explode with the amount of servers we have added recently. I’d like to be able to take advantage of free cooling at night (when the air is cool) but using an electronically adjustable louver door and a set of fans. I am basing this project (for the fan control) off of Alan Parekh’s idea for a PMW fan controller based on temp. (

I am looking to have sets of these plates, but for our prototype we will start with one. What I would like to have is a set of [5] 12V, 0.23A 3-pin fans set in a plate, and then have a louver on one side (to be able to close and open the openings to the fans based on temperature). I would also like to have the fans obey a set of simple rules, too.
• IF [(internal temp of room) >= 70*F] AND [(external temp) >= 70*F] THEN [do nothing, keep fans off, louver closed]
• IF [(internal temp of room) >= 70*F] AND [(external temp) < 70*F] THEN [open louver, turn on fans]
• IF [(internal temp of room) < 70*F] AND [(external temp) >= 70*F] THEN [do nothing, keep fans off, louver closed]
• IF [(internal temp of room) < 70*F] AND [(external temp) < 70*F] THEN [do nothing, keep fans off, louver closed]

The current PWM Fan project setup is about 80% of what I need, as you can set temps and then have fans go on and off at those temps. What I need to be able to do (and this is where I would call on your expertise) would be to have the chipset send out a signal to a DC motor (maybe relay) as needed (as all of this is going to be powered by 12DC wall wort adapter) to turn on (to open the louver door), and then stop once the louver was all the way open (like it hits a switch once it is open 100%). When it needs to close the door, it sends a reverse signal to the motor, and then the louver doors shut, until they are 100% closed, and then the motor shuts off.

The space for the plate is 43” x 10”. I’ve already assembled and mounted the fans, the holes have been cut in the plate, and I have a space for a project box at the top to keep the prototype electronics in. I have purchased the 5 fans (, and I have a power supply from a dead device that gives 12V DC, 1.7A. I can get more power if needed from another adapter, as I have plenty. I don’t care about individual fan speeds or individual fan control on this.

This is for a startup company data center. I’d prefer to bring in a good contractor rather than a firm for this. I like to get creative, keep things in-house, and fund projects to keep all of us here active, learning, and expanding our minds in areas we haven’t seen before.

I would like to learn some PIC programming along the way if you are so inclined to use a PIC, or maybe an arduino? I am quite handy, (drill, solder, weld, cut, some programming, etc) so the physical work and assembly I can take care of. I leave to you the circuit and chip programming :-D

Budget is negotiable, but it will be determined by your depth of understanding, experience, and of course after we communicate.

What do you say?



Please LOG IN to apply online.

« Go back to category
Is this job ad fake? Report it!   
Recommend to a friend
Published at 20-04-2011
Viewed: 2243 times