My first rheobus

I made my first ever rheobus over the long weekend. It's in a "functional" state, not trimmed down or installed yet, but most importantly...it works

Take a look and tell me what you think:
http://home.austin.rr.com/rossmisc/

It only controls 4 fans, but I am thinking that with 1/2" knobs instead of the 7/8" ones that I have, it could probably fit 6 on there with the 16mm pots

Ross

Looks pretty decent and nice use of the Radio Shack heatsinks.

Welcome to the forums.

Nice circuit, and very nice soldering. I made my fanbus recently, and I found there was quite a learning curve on the soldering. Nicely done!

How hot do the heatsinks get? Approx what load (in mA) does it take for the heatsinks to really be necessary?

Thanks -- Paul

Thanks everybody!

Silversinksam--
Hehe. At least Radio Shack HAD sinks. Fry's, which is about 1000x as large as RS and has 100x more components hanging out, didn't. As a bonus, I got to use a little more of that freakin' $9 tube of heat compound

macklin01--
I haven't run it more than a few minutes yet, but the sinks didn't feel like they got over ambient...but it was sitting outside the case too. I wasn't going to use them at all because I don't have a serious load yet, but most people say to use them regardless. If nothing else, I am sure it's better in the long run and again, it looks a little more substantial with them

Well, the 317T only handles 1.5A each and the back of the packaging says it dissipates 15W. I believe the sinks are only 3W, but at least they'll help pull it away from the 317T.

What I can try to do is put a few fans (varying currents) on one channel and see how hot each gets with .15-1.25A on it. The biggest single fan I have is still only .5A and the smallest is .15A. Maybe I can do that today in the background while I am working...

Ross

Ross said:

Thanks everybody!

Silversinksam--
Hehe. At least Radio Shack HAD sinks. Fry's, which is about 1000x as large as RS and has 100x more components hanging out, didn't. As a bonus, I got to use a little more of that freakin' $9 tube of heat compound

macklin01--
I haven't run it more than a few minutes yet, but the sinks didn't feel like they got over ambient...but it was sitting outside the case too. I wasn't going to use them at all because I don't have a serious load yet, but most people say to use them regardless. If nothing else, I am sure it's better in the long run and again, it looks a little more substantial with them

Well, the 317T only handles 1.5A each and the back of the packaging says it dissipates 15W. I believe the sinks are only 3W, but at least they'll help pull it away from the 317T.

What I can try to do is put a few fans (varying currents) on one channel and see how hot each gets with .15-1.25A on it. The biggest single fan I have is still only .5A and the smallest is .15A. Maybe I can do that today in the background while I am working...

Ross

Click to expand...

Ross, thanks for the quick response. Okay, so the 317T gives out 15W when at full load ... okay. Yep, those sinks are definitely going to be useful, at least for larger loads. I'll be interested to see what kinds of results you get with a larger load ...

Again, I'd like to congratulate you on your nice work! -- Paul

awesome job! i wish i had 1337 solder skills and stuff
like you! if i tried something like that i'd end up with
a couple knubs in replcace of me fingers, i'm that bad!

nice, just one question, why didn't you use strip board? i thinkit would be alot easier then wiring everthing.

Thanks again

Starfox--
I just went really slowly...I made a 4-switch fan bus right before this, so I had some recent practice soldering. I am used to soldering wires, but not those damn little specks on the board. Yikes.

overclocker--
Definitely a good idea. I just happened to have that board sitting in a box from a passive crossover project that never quite got done and I wasn't really sure how everything was going to fit. The wiring really wasn't that bad, but it would definitely look cleaner. Maybe for version 2 I said that I wouldn't make another unless I had to, but you never know...I might get bored one day

Ross

Very neat!

I like it! I did something similar, but with LED bargraph to indicate the voltage (and a tinted plexi faceplate):

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

I put it all in a cd-rom casing, and then used the cd-rom (well cd-rw actually) fan to pull air through the unit. Seemed to work reasonably well.

Yours is much neater on the inside though

Re: Very neat!

pHaestus said:

I like it! I did something similar, but with LED bargraph to indicate the voltage (and a tinted plexi faceplate):

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

I put it all in a cd-rom casing, and then used the cd-rom (well cd-rw actually) fan to pull air through the unit. Seemed to work reasonably well.

Yours is much neater on the inside though

Click to expand...

Clever use of the old CD-RW! I think that the mounting can be one of the most difficult points. I used my Antec EasyUSB for mounting, like here. -- Paul

Sweet! I thought about doing the voltage monitor (can't seem to find the 3914 chip or equivalent anywhere locally). My thought was to make the bar graph wrap around the outside of the knobs (I'd definitely need small LEDs and smaller knobs)...I think that would be bad a$$, but that would also probably be $50+ in LEDs alone

The CD case is a good idea and judging from the few temps I've measured so far, a good idea...especially with the fan.

The first run (.5A fan on full blast) measured 104°F after 10 min. in a 75°F room. The good news is that it cooled to 95°F in 20 seconds after shutting it down. I didn't wait to see how long ambient took to reach yet. That load temp was measured with the thermometer stuck in the middle sink fins, touching the screw holding the 317 to the sink. The fins themselves were a little warm to the touch, but nowhere near hot.

I've got .75A on it now (2 fans), but the digital thermometer that does fit in the sink is pegged @ 110°F rather quickly. I am trying to use a big bulb thermometer to measure from the font, but it's acting like a sink itself...it's taken a while just to get over 105°F on the same .75A and it's been running for about 30 min. now. My guess is that if measured like the .5A was, it would have no trouble hitting ~115°F on the screw.

Paul--
If you are running close to .5A or more per 317T, the heatsinks are probably a good idea

I'll need to try to find a way to extrapolate the difference between the measurements with the different thermometers. I guess I can get a .15A and .25A fired up on the other ones while I am waiting, huh?! More to come later...

Ross

Ross said:

Paul--
If you are running close to .5A or more per 317T, the heatsinks are probably a good idea

I'll need to try to find a way to extrapolate the difference between the measurements with the different thermometers. I guess I can get a .15A and .25A fired up on the other ones while I am waiting, huh?! More to come later...

Ross

Click to expand...

Ross, thanks for the information. You might try getting a $10 digital thermometer at walmart or target. They usually have a lead with a thermistor that's pretty darn responsive. (For the "outside" temperature.) That should work well for your purposes ...

I actually am not using 317T's. I used standard NPN transistors in my circuit. I vary the base current with a low-wattage potentiometer, which, in turn, varies the voltage across the fan. So long as I stay in the 0 - 800 mA range, no heatsinks are required on any of the components.

Thanks again for the information on your design. I look forward to reading more of your results! -- Paul

Yeah, I will definitely need to get something a little more flexible in terms of measuring those temps. The big bulb thermometer never moved off of 105 and the little digital one wouldn't read under 90 on the .25A load sink....just stuck on "Low". If I can, I'll hit WalMart or Target today and pick up one of those thermometers. Otherwise I'll try to get to it tomorrow.

If you can run .8A w/o a sink and it stays fairly cool, I'll need to look into it a little further because after running the .75A full load for an hour, the 317 sink was mighty warm to the touch! 1.5A would probably produce some serious temps and x 4, I'd probably need to add an 80mm fan just for the fan control...HEHE. Of course my total fan draw is only 1.45A for all of them at full load, so spread across 4 sinks, it shouldn't be very warm at all. I'll just need to reconsider when I go with higher draw fans or start putting more than one on each circuit...

Ross

Ross said:

Yeah, I will definitely need to get something a little more flexible in terms of measuring those temps. The big bulb thermometer never moved off of 105 and the little digital one wouldn't read under 90 on the .25A load sink....just stuck on "Low". If I can, I'll hit WalMart or Target today and pick up one of those thermometers. Otherwise I'll try to get to it tomorrow.

If you can run .8A w/o a sink and it stays fairly cool, I'll need to look into it a little further because after running the .75A full load for an hour, the 317 sink was mighty warm to the touch! 1.5A would probably produce some serious temps and x 4, I'd probably need to add an 80mm fan just for the fan control...HEHE. Of course my total fan draw is only 1.45A for all of them at full load, so spread across 4 sinks, it shouldn't be very warm at all. I'll just need to reconsider when I go with higher draw fans or start putting more than one on each circuit...

Ross

Click to expand...

Ross, thanks for the response.

Actually, I suppose if you wanted to, if you had a thermistor, multimeter, and calculator handy, you could just "make" your own. (a bit tedious, though! )

I'm addicted to my thermometer now. I thread the probe inside my case (or out the window) and switch between inside and outside temps. I'll see the temp go up to 45C in MBM5 and say to my wife, "Yep, the room temp must be at least 26 or 27C! )

Hmm, well, the transistors are rated at 800 mA, and I mentally try to keep it below 500 mA just to be well within the range. Because they're on the base, I can get away with (much cheaper) 1/4 W rheostats. I also use a 1A SPST relay and 1/4 W zener diodes in my setup. All were cool to the touch when I was testing. (I've had it in my system for a couple of weeks now.) So, between 3 channels, I can hook up 2.4 A at full capacity with no cooling, and at ultraconservative levels, 1.5 A. Most of my fans take about .12A (case fans) to .17A (my HSF), so I don't anticipate ever needing such capacity, even at the ultraconservative levels. I might add in a 92 mm case fan at some point, but even then ...

Thanks for the heat information -- that's really very interesting! Your design has a lot of merits, too, though. As I understand it (I've never used them myself), they have a very low voltage drop and are pretty stable in terms of voltage fluctuations, etc.

Have a nice afternoon -- Paul

Hehe...mine thinks I am nuts monitoring temps, computer all together and then in pieces a day later, etc.

Yeah, the 317 route seemed functionally a lot better than simply sticking a rheo inline I am pretty impressed with the results of your setup though. I am sure there is no way I'll ever run even .75A on each channel and they definitely wouldn't be full load 24/7 anyway, so I am not overly concerned with the heat given off YET. At .15-.25A max (5 of the 6 fans), I can't get the sinks hot enough to take a reading (90°F min on the thermo), so there can't be much if the room temp is now 78°...so 12° at the absolute max. I am betting that they are either staying room temp or just a few degrees over, which is just fine with me.

PWM is probably the ultimate way to go...

I think I have to actually get some work done now TTYL.

Ross

Re: Very neat!

pHaestus said:

I like it! I did something similar, but with LED bargraph to indicate the voltage (and a tinted plexi faceplate):

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

I put it all in a cd-rom casing, and then used the cd-rom (well cd-rw actually) fan to pull air through the unit. Seemed to work reasonably well.

Yours is much neater on the inside though

Click to expand...

That is very sweet! You should consider writing a How-To and perhaps Joe will put it on the front page if you sent it to him.

Uller (of LCDriver fame and the designer of Caseetc's Maelstrom) has separate tutorials available for LM317T and led bargraphs on his website already. I just linked them together; not worthy of a how to. The only original part was the tinted plexi (though that IS cool, eh?).

Gotta be careful with the part costs on these. I made it for a friend online, and charged him $100 for it. I lost a significant amount of money on the deal. Not for the budget minded.

If I had skills I would make up a pcb. That would definitely be the way to go on these things.

If you want a prefab kit then I suggest this one:

http://www.caseetc.com/cgi-bin/caseetc/F-403.html

cheaper and super beefy heatsinks. Overall I was very impressed with it. You may have to do a bit of rewiring though (the one I got had the knobs working backwards so that turning them clockwise lowered speed).

Ross said:

Hehe...mine thinks I am nuts monitoring temps, computer all together and then in pieces a day later, etc.

Yeah, the 317 route seemed functionally a lot better than simply sticking a rheo inline I am pretty impressed with the results of your setup though. I am sure there is no way I'll ever run even .75A on each channel and they definitely wouldn't be full load 24/7 anyway, so I am not overly concerned with the heat given off YET. At .15-.25A max (5 of the 6 fans), I can't get the sinks hot enough to take a reading (90°F min on the thermo), so there can't be much if the room temp is now 78°...so 12° at the absolute max. I am betting that they are either staying room temp or just a few degrees over, which is just fine with me.

PWM is probably the ultimate way to go...

I think I have to actually get some work done now TTYL.

Ross

Click to expand...

Ross, thanks for the reply. I'm glad to hear that at "normal" loads, the heatsinks don't get too hot. It looks like you have a great setup there.

Thanks for the compliment on my fanbus. I'm pretty new at this ...


I thought about PWM for awhile. The one thing I don't like is that it won't allow the fan RPM monitoring to work. Otherwise, it's super. There's actually a program called "speedfan" (version 4.05 right now, I think) which uses PWM to vary the fan speeds (through the SMbus interface, similar to MBM5). It also monitors temps and can be set to vary the speed with temperatures as you configure it. If you're interested (or anybody else is), I'll dig up the link and post it on this thread.

Good luck getting work done -- I'm trying the same! -- Paul

pHaestus said:

If you want a prefab kit then I suggest this one:

http://www.caseetc.com/cgi-bin/caseetc/F-403.html

Click to expand...

I already have ceramic Rheostats that can handle more of a load(25 watts ea) than the Maelstrom , its the led bar graph that I found interesting

Paul--

Yeah, I had the same problem with my fanbus switches...7V=no RPM. I use Speed Fan for most monitoring. Unfortunately, my fans show up on the ISA Bus and it doesn't control them even when connected to the header. I assume it only works if your fans are running completely off of the mobo headers All my fans are running off of the PS with only the tach wires on the headers now.

Actually, I only have one reading on the SMBus and to this day, I have absolutely no clue what it is...it reads 11°C constantly. Never moves even .01 whether idle or completely stressed and that's an awfully cold reading. I've asked before what it might be....no one has stepped up with a guess yet. Anyone here want to give it a shot?

So much for work...totally unproductive day except for this thread I think I'll jump out of here soon and head to Lowe's for a 1-1/8" hole saw and that thermometer...

Ross