• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Simple and cheap rheobus: do it yourself

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

chrismacan

Member
Joined
Mar 13, 2002
Location
Montreal, Quebec
I have recently installed a homemade rheobus...

It was very simple to build and install.

I bought 3 interior light dimmers from a 1993 Toyota Tercel at my local used auto parts supplier.

There are probably many others that will work, but this one is in plentiful supply.

I got them used for 10$ CDN each. That is about 6.50$ US.

First step is to remove the plastic at the bottom of the dimmer. It makes it easier to get at the pins. Then you solder the yellow 12volt in to one pin, the 12volt out to the other. The 12volt return (which is the black wire beside the yellow 12volt) needs to be connected only through the male and female ends of the molex connectors. Attach a molex connector (male on one end and female on the other) to each end. Then determine where you want to put your new rheobus. You will have to cut holes somewhere to secure it. I chose a drive bay. I drilled holes in the plastic plate, tightened them down and plugged them in.

These dimmers are designed to work on 12volts. They DO NOT get very hot and each one can control a large number of fans.

The first one I used was running my delta 80mm, 2 92mm Panaflo's and 2 120mm NMB's. The Panaflo's are 12volt .52 amps and the NMB's are 12volt .67amps. That makes a lot of power!

The single dimmer I used at first had no problem with all these fans. The only reason I added two more was so that I could vary the fan speeds for intake, exhaust and HSF to perfectly complement each other. But using only one is perfectly OK...

Just make damn sure you make your molex connector with GOOD connections or your fans may stop spinning.:eek: :mad: :mad: :(

All in all this project cost me about 43$ CDN or 29$ US. It took me only 30 minutes to build...Not including time to pick up the dimmers and other pieces.

I will try to post pictures in the future if there is enough interest. Except right now I don't have access to a digital camera. I will make a drawing using MSPAINT over the weekend to show this in more detail.

GOOD LUCK and I hope this saves you some money...
 

stool

Senior Member
Joined
Dec 20, 2000
Location
Albany, NY
I don't know if you have Radio Shack in Canada, but if you do, they sell 25ohm 3watt rheos for about $4.00 US. Add a 4 pack of knobs for $5.00 and you've saved about $20.00
 
OP
C

chrismacan

Member
Joined
Mar 13, 2002
Location
Montreal, Quebec
stool said:
I don't know if you have Radio Shack in Canada, but if you do, they sell 25ohm 3watt rheos for about $4.00 US. Add a 4 pack of knobs for $5.00 and you've saved about $20.00


There are much better places in Montreal for electronic parts...I use Addison and Active. Their prices make it not worthwhile going to Radio Shack again...

Problem is however, my 120mm fans pull at least (.67a x 12v = 8.04w). The 92mm pull at least 6.24w. I'm not sure but I think those rheos would burn out pretty fast with the loads I am running...

These automotive rheostats are rated pretty high. But I don't know the specs on them....:D
 
Last edited: