diode reader

simplesid · 08-25-2002, 11:52 AM

i just set up a reader and cant get the remote reading to work properly. its reading -198 F anyone know what might be the problem (im useing a max 6658)

bigben2k · 08-25-2002, 05:33 PM

Check if:
1-the chip is powered
2-the probes are not too long
3-none of the conections cross each other.

tokamac · 08-25-2002, 06:16 PM

chances are you have a fault in the circuit somewhere... The fact that it is reading so low...

most theromcouples are rated for a certain temp range (the most common is copper constantan, -180C to 400C) and -198 sounds like the low end of your particular probe.

Here is how a thermocouple (diode) works: Two dissimilar metals are fuzed together. Since they are different metals there is a voltage drop (contact potential) accross the interface. This voltage drop increases with increasing temperature.

so your temp probe is just a calibrated voltmeter. which also means if the metal in your thermocouple is touching a charged surface you will get erronious readings.

sorry if that was too disjointed...

Tokamac

SonixOS · 08-25-2002, 06:31 PM

ur problem is that u put the wires in the wrong place, desolder them and switch them. I had that problem. Leave the ground wire (if u have one) in the same place, it doesnt really matter much. But make sure u switch the other two.

simplesid · 08-25-2002, 08:05 PM

just tried switcking them... still the same reading
im reading off the XP internal
the local is reading correct
just haveing trouble with the remote reading

simplesid · 08-25-2002, 10:07 PM

ok i just resoldered the wires.... now my temps are...
case 77 F
cpu 68 F
water 71 F
room 73 F
sound right ???

MadDogMe · 08-26-2002, 08:54 AM

What are you using to cool the CPU?. Bong?,TEC?. cause it being below ambient is stange otherwise. it being cooler than the water cooling it definatly!

...

bigben2k · 08-26-2002, 10:12 AM

Quote:

Originally posted by simplesid
ok i just resoldered the wires.... now my temps are...
case 77 F
cpu 68 F
water 71 F
room 73 F
sound right ???

Case: 25 C
CPU: 20 C
Water: 22 C
Room: 23 C

Either you just turned on the comp, or you are running that CPU at basically idle. Which CPU is it?

simplesid · 08-26-2002, 11:47 PM

xp1700
fan/ hc
custom block
those reading were off i resoldered everything, and used another ic (still max 6658) ant the temps are better now
case 75 F
cpu 86 F
water 77 F
room 72 F

bigben2k · 08-27-2002, 08:25 AM

Do you have a pic, or a description on how you wired that chip?

simplesid · 08-27-2002, 09:41 AM

the cpu temp does not go up (goes down a couple degrees)
when i shut my pump/fan off..
the under chip temp goes up tho...

airspirit · 08-27-2002, 09:51 AM

I wish MY temp reader told me my CPU was -198 degs ... I'd have a frickin' party and call the Vatican (Saint Airspirit ... patron saint of ugly hose-filled computers ... naw).

08-25-2002, 11:52 AM	#1
simplesid Cooling Neophyte Join Date: Mar 2002 Location: USA Posts: 18	diode reader i just set up a reader and cant get the remote reading to work properly. its reading -198 F anyone know what might be the problem (im useing a max 6658)

08-25-2002, 05:33 PM	#2
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Check if: 1-the chip is powered 2-the probes are not too long 3-none of the conections cross each other. __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

08-25-2002, 06:31 PM	#4
SonixOS Cooling Savant Join Date: Mar 2002 Location: Silver Spring, MD Posts: 282	ur problem is that u put the wires in the wrong place, desolder them and switch them. I had that problem. Leave the ground wire (if u have one) in the same place, it doesnt really matter much. But make sure u switch the other two. __________________ -sonix- ======================= Antec SX830 Abit KR7A-133 MSI Geforce3 Ti200 VT128 TV-IN and TV-OUT Sound Blaster Audigy Linksys LNE100 V2.0 Toshiba DVD Drive 40x/16x IBM Deskstar 60GXP 60gig Watercooled http://www.sonixnet.tk =======================

08-27-2002, 08:25 AM	#10
bigben2k Responsible for 2% of all the posts here. Join Date: May 2002 Location: Texas, U.S.A. Posts: 8,302	Do you have a pic, or a description on how you wired that chip? __________________ WBTA (Water Block Testing Alliance) Nordic Hardware WC 101

08-25-2002, 06:16 PM	#3
tokamac Cooling Neophyte Join Date: Aug 2002 Location: G-Town NC Posts: 51	chances are you have a fault in the circuit somewhere... The fact that it is reading so low... most theromcouples are rated for a certain temp range (the most common is copper constantan, -180C to 400C) and -198 sounds like the low end of your particular probe. Here is how a thermocouple (diode) works: Two dissimilar metals are fuzed together. Since they are different metals there is a voltage drop (contact potential) accross the interface. This voltage drop increases with increasing temperature. so your temp probe is just a calibrated voltmeter. which also means if the metal in your thermocouple is touching a charged surface you will get erronious readings. sorry if that was too disjointed... Tokamac

08-25-2002, 08:05 PM	#5
simplesid Cooling Neophyte Join Date: Mar 2002 Location: USA Posts: 18	just tried switcking them... still the same reading im reading off the XP internal the local is reading correct just haveing trouble with the remote reading

08-25-2002, 10:07 PM	#6
simplesid Cooling Neophyte Join Date: Mar 2002 Location: USA Posts: 18	ok i just resoldered the wires.... now my temps are... case 77 F cpu 68 F water 71 F room 73 F sound right ???

08-26-2002, 08:54 AM	#7
MadDogMe Thermophile Join Date: Aug 2002 Location: Just shut up ;) ... Posts: 1,068	What are you using to cool the CPU?. Bong?,TEC?. cause it being below ambient is stange otherwise. it being cooler than the water cooling it definatly! ...

08-26-2002, 11:47 PM	#9
simplesid Cooling Neophyte Join Date: Mar 2002 Location: USA Posts: 18	xp1700 fan/ hc custom block those reading were off i resoldered everything, and used another ic (still max 6658) ant the temps are better now case 75 F cpu 86 F water 77 F room 72 F

08-27-2002, 09:51 AM	#12
airspirit Been /.'d... have you? Join Date: Jul 2002 Location: Moscow, ID Posts: 1,986	I wish MY temp reader told me my CPU was -198 degs ... I'd have a frickin' party and call the Vatican (Saint Airspirit ... patron saint of ugly hose-filled computers ... naw).

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