wiring for Hoots Cohesive Air cooling setup?

[e_storm]

Pardon me if this has been covered already in previous posts..I did a search but didn't come up with the answer.

I need to know how to wire up the electrical part of the cohesive air cooling rig. Heres what I have so far:

The blower (obviously)
banana plugs
LM338K -5 amp Adj position volt reg (digikey)
5k ohm potentiometer (radio shack 271-1714)

I haven't messed with electronics/electricity in a long time so I don't remember enough to construct a circuit board with proper voltages/current/resistance.

From the article, it appears that:
1) I was supposed to get a 1-2k ohm potentiometer?
2) I still need 1 fixed resistor (120ohms?)
3) I still need 2 capacitors (.1uF and 1 uF)

Once I know exactly what parts I need, I can figure out the hookup part. I just wanna make sure I have all the right stuff before I fry something and the article is a bit confusing. :D

heres the article: http://www.overclockers.com/tips461/index03.asp

heres a pic of the schematic..

[jbslow]

I ender up using the "2C647A" blower its exactly the same shell but it runs with an AC motor. I also built a nice filter box but its all in the spare room now I'm working on the H2O rig .:cool:

[e_storm]

bump..

If no one knows, no big deal... I got an electronics/circuitry book today and will figure it out given a little time. :)

[Hoot]

Unfortunately, that article was followed up by a lengthy thread in the cooling forum that might have been missed. In the follow-up,

http://forums.overclockers.ws/vb/showthread.php?s=&threadid=13998&highlight=cohesive

I recommended either getting the 2C647 instead of the DC version, or if you already got the DC version, getting the AC equivalent to that DC motor (Grainger sells one) and an AC fan speed control, which makes the process a lot simpler.

If you still want to go ahead with the DC version and not losing what you already have invested, then yes, you will need those components. Unfortunately, I could not find a 120 ohm resistor at Radio Shack, but a 220 will work. Also, if you can not find the .1uf tantalum at your Radio Shack, you can use 1.0 uf for both caps. You will also need a small heatsink for the LM-338K. I started putting together a comprehensive article on the step-by-step construction, but got real sick and wound up never completing it. It had slipped my mind until I stumbled upon the collection of pictures I had started compiling to guide people through the process of building the DC regulator. After I had gotten over my infection, the AC version was so popular, I put the project on a back burner and you know how that goes.

Here are some pictures from that never finished article:

Hoot

[Hoot]

-and-

[Hoot]

typical surface mount heatsinks available. Any one will do.

[Hoot]

You will need to drill the mounting holes somewhere convenient on you case chassis, preferably near an exhaust fan since a little heat comes off the regulator heatsink. Use the pre-drilled heatsink as a template. Here is a small piece of aluminum I chose to use as a build example from here on:

[Hoot]

Grease up the bottom of the heatsink

[Hoot]

Grease up the bottom of the regulator.

[Hoot]

Open up the mounting kit and remove the Mica insulator. Seat the Mica insulator on the regulator. Try not to lose the rest of the hardware in the mounting kit. :D

[Hoot]

Grease the Mica insulator

[Hoot]

Seat the regulator with Mica insulator onto the heatsink.

[Hoot]

Unpack the rest of the mounting kit hardware. You should have all of these:

[Hoot]

Seat the heatsink / regulator assembly onto your drilled chassis spot. Make sure you de-burred the drill holes so there are no rough edges on them, before you seat the assembly. Insert the screws and slide on the shoulder washers. If you drilled carefully, the shoulder washers will center themselves in their holes and that, combined with the screws tolerance will center the heatsink assembly so that the two lead coming from the regulator do not touch the sides of the holes in the chassis. This is critical as you do not want them to short out to the chassis.

[Hoot]

Install the rest of the hardware. The small lug will be the electrical connection to the regulator case, which is the output of the regulator. You can put the lug on either screw, to aid in layout. The shoulder washers are non-conductive and the flat washers sitting on top of them do not touch the chassis. After you are done tightening the nuts, check the regulator case and two pins with an ohmeter to make sure none of them are shorting to the chassis.

[Hoot]

I apologize for the bandwidth this has taken so far. Unfortunately, this is where my article left off. I have yet to show how to mount the resistor and two capacitors, nor the output control pot and inter-related wiring. Some of you may be able to figure it out from here. For the rest, I will finish this some time soon. Sorry for the let-down, so close to the climax.

Hoot

[e_storm]

thanks Hoot..

[Hoot]

Okay, here's the final installment.

Some build notes are in order though.

The voltage adjust pot is pictured very close to the regulator for the sake of fitting it in the picture. You can mount it anywhere you want. The size of the wire going from the pot to the regulator is not critical. Anything >= 26ga. will do. I recommend using either twisted pair or parallel pair (zip cord) to reduce the chance for common mode noise problems. This is not a big deal, just nit-picking.

I did not show the actual +12V wire from the PSU going to the regulator, nor the wire going from the regulator to the blower for the sake of keeping the picture from getting too cluttered. You can figure it out, I'm sure. Use as large a guage as practical. Anything >=18ga. will do. Ditto on the return wires (black) also not shown.

If you have any questions I have not covered, feel free to post them here or PM me.

73, Hoot

[e_storm]

I'm in the middle of learning about circuitry for this project, got a book and a few components, but your pictures and explanation will help trememdously.

[e_storm]

For those planning on undertaking this project and see Hoot refer to a regulator a number of times but only see the underside of it in the pictures above. It is the LM338K 5amp adj position voltage regulator, and can be bought from Digikey.com (I had trouble finding the right one from radioshack).

I am attaching pics of the packaging with the item number, as well as the actual component itself.

[e_storm]

and the component...
this is the best pic I could get that would show the writing on the regulator.

[e_storm]

I put together a breadboard to test the new circuit. 2 questions,

1) seems that wherever I put the 2 leads going to the blower, I get full power at the blower, the Pot doesn't reduce the V...perhaps I just need to put the leads in different places, not sure.

2) is the wiring on the breadboard correct.

I was just gonna PM u, but I needed you to see the pic.