Thermal capacitance and resistance of conductive material

Thread Starter

kalemaxon89

Joined Oct 12, 2022
234
Hello everyone.

In my spare time I am working on this project:
I have a strip of conductive fabric that, bound around the place, gets hot when current flows.
In addition to the measurements you follow with instruments in the lab, I would like to try to simulate its behavior on LTSpice with the classic model I give below:
SmartSelect_20230605_110250_Samsung Notes_1.png

EDIT: There is a writing error .. Rse is the parasitic resistance between sensor (NTC) and environment .. and Rxe is the one between object (wirst) and environment

The pattern is correct right? Is there anything missing?
How do I choose parameter values highlighted in yellow:
1) Rxs
2) Rse
3) Cs
4) Cx

I attach NTCs that I am using.
 

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Last edited:

Alec_t

Joined Sep 17, 2013
14,280
Is there anything missing?
Where is the heated fabric? Shouldn't its thermal capacity, temperature and thermal resistance(s) to the environment be modelled?
Are the wrist and 'the object' the same thing?
Are the NTC and the sensor the same thing?
Does 'the environment' include the heated object?
Why is the 'resistance between NTC and environment' represented twice, with different values?
How do I choose parameter values highlighted in yellow
By guestimation, unless you have some actual values for reference.
 

Thread Starter

kalemaxon89

Joined Oct 12, 2022
234
Shouldn't its thermal capacity, temperature and thermal resistance(s) to the environment be modelled?
How? Experimentally what measurements should I make? Do I give it power and count in how many seconds it comes back to room temperature?

Are the wrist and 'the object' the same thing?
Yes

Are the NTC and the sensor the same thing?
Yes
Does 'the environment' include the heated object?
I don't know ... for simplicity no (?)

Why is the 'resistance between NTC and environment' represented twice, with different values?
You are right! There is a writing error :(
Rse is the parasitic resistance between sensor (NTC) and environment .. and Rxe is the one between object (wirst) and environment
 
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