UV Lights affecting RPM montior

[GeekSupportCom]

UV Lights affecting RPM montior

has anyone experienced this before? whenever i turn on my uv lights, the rpm monitor (enermax rheobus+2probe/rpm monitor) shoots up to 5000 or 6000. when the uv is turned off, rpm goes back to 2000.

 

[sharkeeper]

Your wiring is augmenting artifacts of the switching power supply that's used to provide the running voltage for the CCFL. Try relocating the inverter or running the wires in different locations.

-DAK-

 

[GeekSupportCom]

thanks, i'll try moving the wires around.

in the event it is not possible to move the wiring around, is there anything i can do to shield the rpm wire?

 

[sharkeeper]

That's a tough call. The only remedy may be to modify the circuit on the monitor itself by inserting a choke inline with the RPM sensor wire.

-DAK-

 

[GeekSupportCom]

at the cost of sounding like an idiot, what's a choke inline?

 

[sharkeeper]

Choke is an electrical term for inductor. Small ones consist of a few hundred turns of small gauge copper wire tightly wound around a ferrite core. The common unit of inductance is the Henry. Like the Farad (Capacitance), the Henry is rather large so small chokes are ususally microhenries or millihenries. Inductors will block alternating currents. Induced alternating currents are a contibutor to interference in simple instrumentation.

-DAK-

 

[compudog]

You could try a little ferrite coil you can get at Radio Shack and make a few wraps of the leads for your RPM monitor. The ferrite coil looks like a dull colored donut. They are cheap and may work for your situation. Shuttleteam probably can explain how.

 

[OverVolt]

Originally posted by: shuttleteam
Choke is an electrical term for inductor. Small ones consist of a few hundred turns of small gauge copper wire tightly wound around a ferrite core. The common unit of inductance is the Henry. Like the Farad (Capacitance), the Henry is rather large so small chokes are ususally microhenries or millihenries. Inductors will block alternating currents. Induced alternating currents are a contibutor to interference in simple instrumentation.

-DAK-

Whoa i'm impressed, i'm guessin your some type of electrical engineer.

 

[Slammy1]

When I first saw this my thought was they must be using an optical device for measuring rotational speed. If that's the case, the change in reflectance can cause it to read 2 times per spin. We used to use tape for contrast, and either reflective or black would work depending on the surface being measured. The wrong one might not read, might read twice what it should if it was being especially sadistic that day. I don't claim to understand the mechanics of computer RPM measurement, but you might need to block the light since artifacts from wiring shouldn't affect anything unless they're moving. Again, I'm not certain at all of the mechanics of the computer, but I have done some precise rotational velocities on bigger things.

 

[GeekSupportCom]

thanks for the help everyone, it's grealy appreciated

after doing some testing, i think it's the power coming from the inverter. if i just use the top uv light OR bottom uv light alone, my rpm monitor stays at a constant 2000-2100RPM. the instant i use both uv lights, it hops up to 5300RPM and if left alone long enough 6000.

 

[sharkeeper]

When I first saw this my thought was they must be using an optical device for measuring rotational speed. If that's the case, the change in reflectance can cause it to read 2 times per spin. We used to use tape for contrast, and either reflective or black would work depending on the surface being measured. The wrong one might not read, might read twice what it should if it was being especially sadistic that day. I don't claim to understand the mechanics of computer RPM measurement, but you might need to block the light since artifacts from wiring shouldn't affect anything unless they're moving. Again, I'm not certain at all of the mechanics of the computer, but I have done some precise rotational velocities on bigger things.

Brushless fan tachometric signals emanate from a Hall Effect sensor actuated by the electronically commutated motor's permanent magnets. There are optoelectronic (as well as proximative capacitive) tachometers but they will never be found in a bargain brushless fan motor!

after doing some testing, i think it's the power coming from the inverter. if i just use the top uv light OR bottom uv light alone, my rpm monitor stays at a constant 2000-2100RPM. the instant i use both uv lights, it hops up to 5300RPM and if left alone long enough 6000.

Does the other lamp dim noticeably when the second one is energised? It's quite possible that the inverter is on the brink of operating outside its stable range and is oscillating. Beware of the Rogue PWM mode! :Q

-DAK-

 

[GeekSupportCom]

nope. the brightness level is the same when the 2nd tube is energized. although i must say, do NOT touch the pcb of the inverter trying to hot-plug the 2nd tube - my thumb has a nice scorched mark. i thought the orange flame was the something w/ the pcb (the solder point got me), not me! good thing i had enough calluses to not rip the skin

 

[GeekSupportCom]

thanks for the info. i was able to re-arrange the fan's wire away from the inverter and now the uv doesnt affect the rpm monitor.

 

[AgaBoogaBoo]

Originally posted by: OverVolt

Originally posted by: shuttleteam
Choke is an electrical term for inductor. Small ones consist of a few hundred turns of small gauge copper wire tightly wound around a ferrite core. The common unit of inductance is the Henry. Like the Farad (Capacitance), the Henry is rather large so small chokes are ususally microhenries or millihenries. Inductors will block alternating currents. Induced alternating currents are a contibutor to interference in simple instrumentation.

-DAK-

Whoa i'm impressed, i'm guessin your some type of electrical engineer.

You have no clue dude, everytime I read one of his posts, I'm impressed! :Q Seriously!

 

[Horsep0wer]

anyone know of a UV light i can get that won't do this, or affect other things in my system? i'm a complete noob when it comes to case lighting and cables. i just got a case that has a window, so i want to put in a UV light with UV rounded cables and UV split looms. another thing, are rounded cables ok to use nowadays? i remember a time when it was recommended they not be used. what should i look for in a good cable? also, if you know of a place that has fair prices for this stuff, i would appreciate that info also. i checked SVC.com, but they seem to be out a lot of stuff i am considering.

 

[GeekSupportCom]

from personal experience, i've never had any problems with rounded cables. my ide/floppy cables are uv reactive too -- from bestbyte.net

all my uv stuff (2xUV Tubes, inverter, sound module) came from svc.com.

 

[bjc112]

Originally posted by: OverVolt

Originally posted by: shuttleteam
Choke is an electrical term for inductor. Small ones consist of a few hundred turns of small gauge copper wire tightly wound around a ferrite core. The common unit of inductance is the Henry. Like the Farad (Capacitance), the Henry is rather large so small chokes are ususally microhenries or millihenries. Inductors will block alternating currents. Induced alternating currents are a contibutor to interference in simple instrumentation.

-DAK-

Whoa i'm impressed, i'm guessin your some type of electrical engineer.

Very impressed. Go Shuttle.

 

[sharkeeper]

anyone know of a UV light i can get that won't do this, or affect other things in my system?

Use four Lumileds Luxeon Star emitters. They come in a flavor known as Royal Blue. These will put out considerable sub 400 nM energy! NEVER stare into one at full bore. The UVA energy is quite high and hard on the eyes although germicidal UV (C) is nearly absent. These sources only require a current limiting resistor to work and impose absolutely no environmental interference to surrounding components. Well short of any quartz window uv-clear EPROMS! Trust me, if your mainboard has one of these, there is no way you would be showing it off! :Q

-DAK-

 

[Horsep0wer]

Sheesh Shuttleteam, after reading your posts I feel really dumb! I'm assuming the Lumileds will work without causing any interference with my systems components, correct? If so, where would I find these? Will they cause UV reactive hardware to glow like a cold cathode UV light? I'm sure they will because you recommended them, but I want to make sure.

Thanks to everyone for the replies. I am, however, having a hard time finding UV reactive split loom for my PSU/audio cable wires. I don't want to undo the Molex plugs, so the split loom will work just fine. Can ya help me out.

Thanks again.

 

[sharkeeper]

You can find more information from here.

These lamps require heatsinks (!) when driven at 100% so you must take that into consideration. Your fluorescent "targets" will glow with great brilliance when exposed to the RB luxeon star! I built a few guns for the HVAC guys that are using fluorescent dye in refrigerant and they are pleased with the results. This could be considered more of an exotic method to enhance your case innards! Not as esoteric as tritium distended borosilicate tubes that glow for 20 years with no power but still...

-DAK-

 

[sharkeeper]

If you want to make entire room glow, you can always try one of these!

I think I'll buy a few. I have a four lamp cart. (the kind you see along a highway when workers are present at night) Replace the lamps with those and you have a pretty powerful longwave source! That would probably make a scorpion glow a full kilometer away!

-DAK-