Triky question on resistance

WBahn

Joined Mar 31, 2012
29,976
So, It was a PTC.

Not just a thermistor or Resistor.
What about "Device the resistance to current decreases when temp increases," says PTC to you?

PTC is not a device (unless you are thinking of something other than I am). PTC simply stands for Positive Temperature Coefficient, meaning that whatever parameter has PTC behavior, the behavior INCREASES as temperature increases.
 

R!f@@

Joined Apr 2, 2009
9,918
What about "Device the resistance to current decreases when temp increases," says PTC to you?

PTC is not a device (unless you are thinking of something other than I am). PTC simply stands for Positive Temperature Coefficient, meaning that whatever parameter has PTC behavior, the behavior INCREASES as temperature increases.
PTC Resistor. :cool:
Satisfied. ?
 

WBahn

Joined Mar 31, 2012
29,976
PTC Resistor. :cool:
Satisfied. ?
Not really.

I still don't understand why you think the answer is a PTC anything when the question states that the resistance DECREASES with an increase in temperature.

Or why "resistor" is somehow a better answer than "thermistor" (though I'm not saying that you have made that particular claim).
 

MrChips

Joined Oct 2, 2009
30,701
R!f@@, WBahn is just playing words with you.

Since the OP's question was about resistance decreasing with increasing temperature, the behaviour by conventional definition is NTC, negative temperature coefficient (unless one was talking about conductivity, but we are not).

PTC and NTC are just characteristic behaviours, not devices.

So the proper answer could be NTC resistor or NTC thermistor.

What's the difference?

The standard process for creating resistors produces PTC resistors.
NTC resistors require more exotic materials and fabrication.

Hence my answer would be NTC thermistor.
 

#12

Joined Nov 30, 2010
18,224
Sometimes the suckiest threads lead to decent discussions. Sometimes they don't.
I logged in just to say, "Amen" to that.
Some threads seem to be perfectly reasonable when they start, then fall apart as we realize half the words in the question had a different definition for some of the people. Or a perfectly valid question, only to find out it was a complete fluke that happened to a beginner that doesn't realize what he was asking for. Then there are some seemingly basic questions that dredge up the very latest research and we all learn from it. More than once, I was afraid somebody was going to shoot my hat off and found 5 different sources that I had never heard of. You just do the best you can and watch where it goes.
 
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