PT100 amplifier board - redaings seems to be 30 degrees below

dc42

@tony449777 said in PT100 amplifier board - redaings seems to be 30 degrees below:

@dc42 I can’t attach a picture, it will not let me however I can tell you R1 is marked”102” while R2,R3,R4 are all marked “201”

Why can't you attach a picture?

Do both channels give the wrong reading when you connect the 100 ohm resistor to each in turn?

dc42

@tony449777 said in PT100 amplifier board - redaings seems to be 30 degrees below:

Also curious, if the channel 1 on the daughter board is “spi.cs1”
And you have one daughter board with the two ports, then is the second port for the same card “spi.cs2”?

Yes.

tony449777

@dc42 yes

tony449777

@dc42 I’m using the phone application. Every time I try to attach a picture it just says undefined.

dc42

@tony449777 it's easier from a PC, you can just drag and drop a .jpg file into your post.

tony449777

@dc42 Update. Switched out the daughter board for another one I purchased from filastruder and it works fine. It must be the board.

Phaedrux

@tony449777 said in PT100 amplifier board - redaings seems to be 30 degrees below:

I believe I got this daughterboard from Filastruder. It was purchased a while ago, but never used until this build.

How long is a while ago?

c310

@dc42 my 2nd channel died :I( i will be replaceing the chip, on the way want to check other parts. there are 2 pairs of capacitors - c1/c2 + c5/c6 what its default capacity should be?

also there is small black SMD element in between C1 and R1. what is it? what are the parameters?

many thanks!

T3P3Tony

@c310 the schematic for the board is here:
https://github.com/Duet3D/TempDaughterboards/blob/master/MAXTempRTD/MAXTempRTDv1.1.pdf

I assume you are refering to the inductor L1:

two screen shots depending on the version of the PT100 db you have.

it is an inductor such as LB2012T101K

c310

@t3p3tony said in PT100 amplifier board - redaings seems to be 30 degrees below:

LB2012T101K

thank you @T3P3Tony !!!!