rheostat baybus LEDs idea
 

does anybody know of something i can use to switch on and off a few LEDs at different amounts of resistance? im trying to make a rheostat bay bus and i thought it would be cool for it to have an LED (red) turn on at the first third turn of the rheostat, another LED (yellow) for the middle third, and finally another LED (green) for the last third turn. oh, and only having 1 LED on at a time. hopefully there is a simple IC or something that can do this....

I can give you the basics, but not the circuit.

What you want to do, is use a comparator (chip) for the 3 voltage trigger points. Then you'd want to mix the signals through a logic chip (or transistors) so that you only turn one on at any one time.

If you understand that, then I might be willing to put in the time to draw the logic of the circuit.

thanks bigben, thats what i was looking for. i read up on comparators and seems to do what im looking for (a quad-voltage but only using 3 possibly?). as for the logic chip, what do you recommend?. also if you have a few spare minutes, could you draw that up for me? i have the bare minimum knowledge on electronics, but im learning more and more each day.

sounds like a sweet idea, and something new that i haven't seen before... i hope you succeed.

troy.

Sorry Tim, I missed this thread. (Try PM'ing me!)

I'll look into it, but you've got the gist of it.

I ordered a couple of LM311 comparators (DIP package). I should have a circuit drafted before I receive them!

In the mean time, here a link to The rheobus circuit .

(BTW, it's now sold with LEDs)

I used a 10 led bargraph for the fan controller I made (LM317T + pot - based rather than rheostat but same idea.

http://phaestus.procooling.com/baybus/baybus2_s.jpg

The bargraphs come in tri color (red, yellow, and green) I think. :)

Always on top, eh?:D

I thought about that too. Where did you source the led display?

wow! i had totally forgotten about this thread. thanks for taking the time bigben to do that! and pH, those bargraphs are pretty sweet too.

as for other projects, i had received my Maxim samples a while ago and thought i would mess with those. im currently putting together a MAX1668 with 4 remote sensors, and ive been working on some ideas for pelt water blocks that i can make in my dads machine shop. a home made aluminum case is still pretty far away after looking at my current case and trying to get some ideas from it. i also received some acrylic tubing from koslov that im anxious to start making some resevoirs/other stuff out of.

thanks again for taking an interest to this thread!

hehe!! SGStealth's mod... i'm making this currently.. completed one channel.. works very nicely.. very cool.. especially with my SB blue LED which gives those kinda freezing light.. not those cheapo blue light.. but those real cool blue ones.

:D

will post more info here when i'm done. BTW, rememebr to insulate ur LM317/T chip wif a mica sheet. :D

I got Maxim samples too. What did you have in mind?

I also got a tube from koslov! I'm done writing the article for it, but I have yet to find the time to build it!

I'm also trying to get together a block... Ok, you and I need to meet!!! Do you have access to a lathe or a mill (or both)?

Dreamie, what's the difference with the "SB blue LED"? I just ordered a couple of ultrabrights from alltronics.

Well...for the maxim samples i was gonna rig up a sort of water in and out temp sensors and for the other 2 remotes i was gonna put in and out (either air or water) temp sensors on the radiator. when i get around to building it....i pretty much just need to make a block and go to orchard and get some tubing. i already have everything else:via aqua 1300 pump , 220w pelt, a couple panaflos, a all aluminum radiator that my friend gave me off his busted ass 87' dodge (?) truck.

for the acrylic tubing, i plan on making a kind of dual-air trap type of thing (for aesthetics mostly) still have to actually build that too.

as for mill/lathe: i got a Jet mill, a MasterMill and a 6' Nam Sun YMZ lathe (toys!:D ) ill try and post some picts for the kiddys to see soon

not quite sure though, but that shop label it as ultra super bright.. gives a very very nice blue shine.. very cool..

Ok then... let's compare specs!

15 degree viewing angle
current draw: 20 mA
luminous intensity (typical): 1500 mcd (1000 minimum)
voltage drop 3.5 to 4.0
Wavelength: 465 to 470 nm, +/- 10
body: clear

the shop didnt give me any specs. I went to sim lim tower to buy it. it draws 3V. Can still see the light from it very clearly when viewed from the side (eg. can see wire and LED's body)

All right, I've got an idea to up this thing to the next level: digital controls.

Forget turning the knob, just press the "faster" or "slower" buttons.

Gotta get to work.

Dang! It's been done!

http://www.moddin.net/review.asp?ReviewID=29

Here's the circuit, modded with a comparator, so that the LED turns on at a trigger point, not gradually, like the linked design.

(I used PCB123, but if anyone knows of an easier (and free) program that works better, let me know!