whitten@kuhub.cc.ukans.edu (04/01/91)
I've been told that there are temperature probes available which come in like 8 pin dips with the output already linearized an such. Does anyone have any information on the manufacturers of such a product? Thanks, Chris ============================================================================== WHITTEN@KUHUB.CC.UKANS.EDU Chris Whittenburg, Univ. of Kansas WHITTEN@UKANVAX.bitnet Electrical Engineering ==============================================================================
ssave@ole.UUCP (Shailendra Save) (04/02/91)
> temperature probes ...come in like 8 pin dips ...output linearized > information on the manufacturers of such a product? Try National Semiconductor's LM 135, LM335. These are 3pin temp. sensors with 10mV/deg variation. They are linear, and are pretty accurate. Shailendra beaver.cs.washington.edu\!sumax\!ole.uucp\!ssave
bill@thd.tv.tek.com (William K. McFadden) (04/02/91)
Analog Devices and National Semiconductor make some common ones. My favorites are the three terminal TO-92 sensors from National that output directly in degrees F or degrees C (10 mV per C or F, depending on the part number) with no external components other than a power source. Add a component or two, and they can also measure negative temperatures. I've been able to buy the cheapest grade of Fahrenheit sensor from Digi-Key for $2. Add an 8-pin V to F converter (e.g., LM331), and you've got a dirt cheap temperature to frequency converter that's ready to connect to an interrupt line or counter input of a microcontroller. -- Bill McFadden Tektronix, Inc. P.O. Box 500 MS 58-639 Beaverton, OR 97077 bill@videovax.tv.tek.com, {hplabs,uw-beaver,decvax}!tektronix!videovax!bill Phone: (503) 627-6920 "SCUD: Shoots Crooked, Usually Destroyed"
bill@thd.tv.tek.com (William K. McFadden) (04/03/91)
I write: >I've been able to buy the cheapest grade of Fahrenheit sensor from >Digi-Key for $2. Add an 8-pin V to F converter (e.g., LM331), and >you've got a dirt cheap temperature to frequency converter that's ready >to connect to an interrupt line or counter input of a microcontroller. As a followup, Digi-key sells the following sensors from National Semiconductor: Accuracy Temperature Price Part typ@25C/max@25C/max over temp Range Package Each LM34CH +/- 0.8F / 2.0F / 4.0F -40F to +230F TO-46 14.37 LM34CZ +/- 0.8F / 2.0F / 4.0F -40F to +230F TO-92 7.20 LM34DZ +/- 1.2F / 3.0F / 4.0F +32F to +212F TO-92 2.04 LM35CH +/- 0.4C / 1.0C / 2.0C -40C to +110C TO-46 14.34 LM35CZ +/- 0.4C / 1.0C / 2.0C -40C to +110C TO-92 7.77 LM35DZ +/- 0.6C / 1.5C / 2.0C 0C to +100C TO-92 2.34 LM331N Voltage to Frequency Converter DIP8 7.50 These are the 3-terminal sensors I was talking about. The number for Digi-Key is 800-344-4539. The data sheets are in the National Semiconductor Data Acquisition Linear Devices Databook. Digi-key also sells: -- Bill McFadden Tektronix, Inc. P.O. Box 500 MS 58-639 Beaverton, OR 97077 bill@videovax.tv.tek.com, {hplabs,uw-beaver,decvax}!tektronix!videovax!bill Phone: (503) 627-6920 "SCUD: Shoots Crooked, Usually Destroyed"
ken@csis.dit.csiro.au (Ken Yap) (04/04/91)
While we are on temperature probes, has anybody dissected one of those cheap digital indoor/outdoor thermometers made by Micronta and sold by Radio Shack, but probably sold under many other brand names? I notice that the PCB has contacts for additional buttons. Two seem to be for min and max readings. I've also seen an ad for model that has serial output. So it would seem that the chip used has "unadvertised features". Anybody know what the extras are and how to get them?
bc338569@longs.LANCE.ColoState.Edu (Brian Catlin) (04/05/91)
In article <1991Apr4.003110.4141@csis.dit.csiro.au> ken@csis.dit.csiro.au (Ken Yap) writes: >While we are on temperature probes, has anybody dissected one of those >cheap digital indoor/outdoor thermometers made by Micronta and sold by >Radio Shack, but probably sold under many other brand names? I notice >that the PCB has contacts for additional buttons. Two seem to be for >min and max readings. I've taken several of these apart. If I can remember right, it has sixteen pins on it. These pins are ground, positive, high temp, low temp, memory, alarm on/off, high temp out, low temp out, alarm out, set alarm, piezo buzzer out, C/F select, and some others that I can't seem to remember. We use these to run fans and heaters in our greenhouses and they are pretty good for this. They not only have min/max temperature memories, but they also have alarm outputs that can run LEDs or relays to run larger loads. The piezo buzzer output connects to (you guessed it) a piezo buzzer. This buzzer sounds any time either the min or the max alarm temperature is reached. It comes with a small paper that shows all of the connections and it shows how to add LEDs to the three outputs. Sorry, no serial outputs though. Hope this helps! B. J. Catlin bc338569@longs.lance.colostate.edu