100 mv floating signal into TC-08

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do0mn0ob
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Joined: Thu Sep 03, 2020 4:14 pm

100 mv floating signal into TC-08

Post by do0mn0ob »

Hi all,

Having trouble getting a 100 mV (max) signal into a TC-08 using a thermocouple connection, the problem is there's no common signal - my signal is floating but with a 0-100 mV range.

I tried to use a voltage divider between the + and - terminals to bring the + down but it has completely changed the signal and I'm lost for solutions now.

A quick test shows that my transducer outputs 10 mV as expected, however, the presence of the divider (220 ohm and 523 ohm resistors) changes the input from that 10 mV to 1.4 mV. The divider itself produces the correct proportional drop across the 220 ohm resistor but output of the divider is 1 mV, 7 x less than it should be.

Can the terminal board handle this type of signal without a well defined ground?

do0mn0ob
Newbie
Posts: 0
Joined: Thu Sep 03, 2020 4:14 pm

Re: 100 mv floating signal into TC-08

Post by do0mn0ob »

Ignore this, I have found my solution.

Turns out the transducers I inherited were ratiometric, so all I needed to do was reduce the input voltage to 7 V!

:oops:

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