Hi all!
Martin medelec35 gave a nice reply here: http://www.matrixtsl.com/mmforums/viewt ... tor#p97159
Maybe you can/will help again Martin or another expert. Will it be possible to use a PT100 with this component in FC8?
If it should be possible, I suppose it must be connected as a voltage divider and the scaling/linearity from the datasheet for PT100 must be set in the thermistor value in properties.
Thank´s in advance
Br Jorgen
Thermistor component
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Re: Thermistor component
Hi Jorgen,
The PT100 has a very small resistance change with temperature compared to the 10K thermistor.
For example for every degree C change, the resistance will change by 0.4 ohms
Therefore you will need an amplifier to convert the small voltage change into a much
larger one.
So the answer is no, your PT100 won't work in place of a much higher thermistor value without amplification.
The PT100 has a very small resistance change with temperature compared to the 10K thermistor.
For example for every degree C change, the resistance will change by 0.4 ohms
Therefore you will need an amplifier to convert the small voltage change into a much
larger one.
So the answer is no, your PT100 won't work in place of a much higher thermistor value without amplification.
Martin
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Re: Thermistor component
Hi Jorgen,
PT100's also tend to have a constant current source to supply them.
The voltage is then measured across the device.
Microchip have a application note on using RTD's
http://ww1.microchip.com/downloads/en/A ... 00687c.pdf
Have a look at Fig 4.
A Tl341 is a good little reference
Steve
PT100's also tend to have a constant current source to supply them.
The voltage is then measured across the device.
Microchip have a application note on using RTD's
http://ww1.microchip.com/downloads/en/A ... 00687c.pdf
Have a look at Fig 4.
A Tl341 is a good little reference
Steve
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Re: Thermistor component
Hi Jorgen
Some of the resistor values are a bit obscure. I did have difficulty finding some of them and some that where available where "reel" qtys of 5000
This web page turned out to be a godsend.
http://mustcalculate.com/electronics/resistorfinder.php
so for the 2K5 resistors used - see attached screen shot as an example
Steve
Some of the resistor values are a bit obscure. I did have difficulty finding some of them and some that where available where "reel" qtys of 5000
This web page turned out to be a godsend.
http://mustcalculate.com/electronics/resistorfinder.php
so for the 2K5 resistors used - see attached screen shot as an example
Steve
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Re: Thermistor component
Thank´s again Steve.
Talig promised to come bag with an "clean" example from here http://www.matrixtsl.com/mmforums/viewt ... 6&t=21640t with the MAX31865 amplifier this weekend. I think this would be easier to use If not, I will build an analog amplifier. Meanwhile I will look at your data. Thank´s.
Br jorgen
Talig promised to come bag with an "clean" example from here http://www.matrixtsl.com/mmforums/viewt ... 6&t=21640t with the MAX31865 amplifier this weekend. I think this would be easier to use If not, I will build an analog amplifier. Meanwhile I will look at your data. Thank´s.
Br jorgen