Rheostats and You!

Manufacturer: Sidewinder Computers
Supplied by: Sidewinder Computers
Price: $11.50

by Dean Barker  (9/27/2001)

Rheostats and You.  Ok, so it sounds like a film you saw in eighth grade P.E.  The thing is, that Rheostats can be much more useful than people realize.  To start with, let’s explain what a Rheostat is being that you will hear about it often, but rarely what it does or how it works.  The most direct explanation without getting all into electrical resistance and such, is that a Rheostat is a small device that controls the voltage flow via a dial or knob.  Less voltage means less power to turn, for instance a fan, so you get lower fan speeds and lower CFMs if your Rheostat is controlling a fan.  More voltage means more power, more spin, more CFMs on any fan attached.  Modders who play with these have a choice of wiring up one or a bunch in a BayBus.  There are several excellent articles out there on making your own Rheostat BayBus out there.  A BayBus is a small box with several Rheostats that let you control the speed of multiple fans.  Or if you don’t need that much control, you can just wire the Rheostat between two Molex connectors and have a pretty fast and easy control for your devices.

Gary over at Sidewinder Computers was kind enough to send over more of his soldering craftsmanship.  You guessed it a Rheostat with a Molex on each end.  Ready to plug and play.  Hearing about these devices for some time I never really put much thought into needing or using one.  My four year old daughter's computer, has a 120mm fan as intake up front.  Every bit as loud as she is at bedtime.  Her machine of course, has educational Mickey Mouse and Pooh games which are about as demanding on the CPU as Solitaire.  But I also use the machine as a test bed on occasion.  My dilemma was I did not want to turn off that loud 120mm fan, because if I did, that also meant turning the overclocked Duron back to the factory 800MHz, lest I or she get a lock up.  I bet my daughter is the only kid at daycare who has “Numbers with Pooh” being pushed by 963MHz!  When the Rheostat showed up at my door, the lights came on.  As you can see below, now I can control the fan speed from low to full honk by a simple spin of the knob.  I mounted it into a blank 5 ¼ inch bay cover with the locking nut that was included with it.  This is simple, reasonably easy to make yourself item, like the RPM cable we showed you some weeks back.  However, $11.50 to just have it and not to have to drive around to every Radio Shack in town looking for blank Molex connectors and the Rheostat mechanism so you can make it yourself, sure does make things nice. 

Sidewinder Computers can hook you up with one of these very useful and frequently overlooked devices many PCs could use.  The Rheostats they sell are 5 watt jobs.  The total power consumption of the fans you hook up to it cannot exceed 0.70 amps or you can overload it.  This means you can run either a single 120mm fan, two 92mm fans, or three 80mm fans without much fear.  Thank again go out to Sidewinder Computers for hooking us up yet again.

 

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