Pro/Forums - View Single Post - For all you Electronic guru's out there, Temp Probe design

pHaestus · 08-23-2003, 03:55 PM

You need to elaborate on what you wanna do with this probe:

1) Integrate to MBM
2) display on separate LCD
3) just dump results via serial or parallel port somewhere
4) what is it you are monitoring (this will determine the size of probes needed)
5) what is the application (this will determine the accuracy required and therefore the cost).

Examples: You can get 4 probes into MBM via thermistors and a gameport on a PC. Expect pretty bad accuracy, but hey you can calibrate them at least and you can fit them most anywhere and it shouldn't cost you much money at all. I keep thinking that the way to improve www.benchtest.com 's design is to add a wheatstone bridge but I haven't done so yet.

You can make a Dallas 1-wire setup and daisy chain a ton of 0.5C accuracy, 0.125C resolution DOW sensors. No calibration required (never hurts tho). These are larger though and not so easy to place in some locations.

You can make a diode-based setup using Maxim ICs. Also possible to use lots of probes and you can even incorporate an AMD CPU's diode reading into the loop. Easy MBM and speedfan incorporation too. Diodes are a pita to deal with for many reasons, but in theory careful calibration deals with most of them.

I have never heard of a DIY thermocouple reader; I would be interested in one just from the standpoint of seeing how difficult it is to do.

The application and your patience really dictate which of the DIY solutions are better.

08-23-2003, 03:55 PM	#4
pHaestus Big Player Making Big Money Join Date: Aug 2001 Location: irc.lostgeek.com #procooling.com Posts: 4,782	You need to elaborate on what you wanna do with this probe: 1) Integrate to MBM 2) display on separate LCD 3) just dump results via serial or parallel port somewhere 4) what is it you are monitoring (this will determine the size of probes needed) 5) what is the application (this will determine the accuracy required and therefore the cost). Examples: You can get 4 probes into MBM via thermistors and a gameport on a PC. Expect pretty bad accuracy, but hey you can calibrate them at least and you can fit them most anywhere and it shouldn't cost you much money at all. I keep thinking that the way to improve www.benchtest.com 's design is to add a wheatstone bridge but I haven't done so yet. You can make a Dallas 1-wire setup and daisy chain a ton of 0.5C accuracy, 0.125C resolution DOW sensors. No calibration required (never hurts tho). These are larger though and not so easy to place in some locations. You can make a diode-based setup using Maxim ICs. Also possible to use lots of probes and you can even incorporate an AMD CPU's diode reading into the loop. Easy MBM and speedfan incorporation too. Diodes are a pita to deal with for many reasons, but in theory careful calibration deals with most of them. I have never heard of a DIY thermocouple reader; I would be interested in one just from the standpoint of seeing how difficult it is to do. The application and your patience really dictate which of the DIY solutions are better.