Keep in mind the following about me as you read this post... electronics knowledge: 0 soldering experience: 0 clue: 0 Now that we're past that and you understand that some of what I ask may be stupid, on to what I want to do. I want a rheobus. OK you're saying, so why don't I go and buy a nice quality pre-made fully assembled kit like PCmods one or the maelstrom since I don't know what I'm doing? Well...this is where it gets complicated.... I'm kinda after a slightly more custom solution. I will be fitting this into a 5.25 bay, but a good half the width of the bay will be taken up by something else. Therefore this little bugger has to be fairly compact. I only need 3 rheostats at the most (possibly only 2, details on this still have to be planned out once I order my new case and can take more accurate measurements). All the pre-made kits come with 4 big knobs and they're spaced far apart to fit in the bay evenly. I'm fine with smaller knobs placed much closer together. For an example, take a look at those fugly new Enermax cases with the temp monitor/rheobus built into a 3.5 bay http://www.enermax.com.tw/products/cs-5190al.htm That's about what I'm looking for size wise. That all said, here's what I assume are my options: 1. Buy a pre-assembled one and try to modify it to my needs (somehow I don't think cutting it in half or moving stuff around is possible, but figured I'd mention it anyway) 2. Pay somebody with a clue to assemble one to spec for me. 3. Take on building it myself using online guides from bit-tech, virtual-hideout, etc. and a hell of a lot of help from forum people I'm assuming the 1st option won't work (correct me if I'm wrong), and the second has proved rather hard to accomplish (unless any of you are willing to do it!! ), so that leaves me with doing it myself. That also knocks down the quality of this piece considerably, and requires me to track down or buy many of the tools I don't have (which will make it all end up costing a lot more, not including the time and effort). And I'd really rather this be a functional and professional quality piece. So... what are your suggesstions? Oh, and one last question I forgot to put in before, can you control a cold cathode light with a rheostat? I don't want to dim it or anything, just turn it on and off like a regular switch would. Whew! Sorry about all the questions
Your instincts are pretty good. Option three is the rewarding way, the way of the modder. You can almost certainly do it yourself. Professional quality, maybe not the first one, but you will learn a lot, and the second one will probably be outstanding. You can dim a CCFL with a rheostat, sure. For on/off, you would probably want a switch. Try one of these xBus plans on for size: http://www.bit-tech.net/article/52/ Note that a pure rheobus uses rheostats, usually 5W ones, and they are kind of big. They need to be to handle the current. A voltage regulator design will allow you to use small (tiny even) potentiometers to control the fan voltage since the regulator ICs are dissipating the power. (Very little power is dissipated through the pots in a regulator fanbus.) We're here to help. You shouldn't need lots of tools, just a soldering iron and wirecutters I believe, plus a tool to put holes in your faceplate (I like a tapered reamer, but a drill will work or even a knife in a pinch).
Thanks! OK, so I'm assuming "voltage regulator design" would be the elctrobus version of fanbus and I can therefore use the electrobus BT article as a guide. Lucky for me I don't want LEDs so that makes things a lot less complicated. Now one thing I'm confused about. Tthe first circuit is just variable speed (is that just a knob you turn to increase/decrease speed? can this type do 0% or 100%?). The second is a switch variety. Does that mean just toggle switches? The toggle switch functionality is probably closer to what I need, but (call me girly) toggle switches are ugly And seeing as this mod is mostly for functionality, but also for looks, I kinda wanted to avoid toggle switches. Is there a rotary knob-like item that would accomplish the same thing? In other words, like something you'd turn and it'd have 3 positions that it would click on or something... on/off/variable. Does that make any sense?
The voltage regulators can vary the voltage from 0 to 12 volts, but since most fans won't work safely under 7 volts, that's probably all you'll want to do. The fan is still spinning quite briskly at 7 volts. Yes, they do make rotary switches. Try DigiKey.
Yeah, you've got options. The first two of macro's designs just give discrete control of the fan speed. on/off in the first case, and hi/lo/off in the second. As far as switches go, there are many flavors to choose from, so if you don't like toggles, maybe some rockers or pushbuttons would suit you. The last two options offer continuous variable control of your fan speed, so they have rotating knobs for control. As I observed above, proper rheostats are probably too big for what you want to do, so you'd be building a voltage regulator xBus. Voltage regulators are protected against short circuits, they're cheap, and readily available, so they're pretty nice for this application. I kind of like this design by cpemma (you'll see him around here) because the voltage varies between 6.5 V and almost 12V rather than 0-12V. the 0-6V range isn't as useful--it may not spin your fan at all. Since you asked about rotary switches, that's a fifth option for you. You can get off/5V/7V/12V with nothing but a rotary switch and some tricky wiring. you can get more discrete steps than that by either using fixed voltage regulators (like the 7809, a fixed voltage +9V reg) or other tricks. Turning to cpemma again, he's got a novel design using diodes and a rotary switch to get a series of discrete voltages. That circuit would be cheap, flexible, and just about bulletproof. My only concern is that you may have trouble sourcing rotary switches that aren't big and clunky.
Thanks for all your help guys. You've really pointed me in the right direction. I learned quite a bit from the resources you've all listed. Luckily, I was able to get ahold of a good friend of mine who just happens to be an engineer and he's willing to help me out building the thing. Thanks to you guys I at least have more of a clue what to ask for and how to explain to him what I'm trying to do. I'll be sure to post some pics whenever I have some
Clunky? Moi? 26.2mm max diameter for the switch, and I make a bay panel 149mm, so three would be only a shade more than half the width. If you use 21-22mm knobs to hide the mounting nuts (no tat here) any 3-channel baybus will need around the same width. To pick up some soldering tips, have a look at the EPE Basic Soldering Guide , get some bits of stripboard and practice with bits of wire before trying components. Best of luck!
You saw that jennyfur wanted to do something like this (http://www.enermax.com.tw/products/photos/5190vr.jpg), right? So yeah, I think you may be a little clunky for that, although it may work.
It's a double-decker bus! Take your point, I'm looking to build one that sort of area on the Maplin Transfer Panel (macroman review), it really needs a sub-panel behind to mount some 9mm pots with wee knobs. Room for two in comfort, three would look cramped.
