Electronic Device And Electronic Circuit

Data of electronic device , PCB Design and electronic circuit

Web basicelectronic.blogspot.com

Tuesday, September 05, 2006

Isolated Thermocouple Transducer Circuit

The AD202 are general purpose, two-port, transformer-
isolation amplifiers

In applications where the output of thermocouples must be
isolated, a low drift input amplifier can be used with an
AD204,as shown in Picture.

A three-pole active filter is included in the design to
get normal-mode rejection of frequencies above a few Hz
and to provide enhanced common-mode rejection at 60 Hz.
If offset adjustment is needed, it is best done at the trim pins
of the OP07 itself; gain adjustment can be done at the
feedback resistor.
Note that the isolated supply current is large enough to
Mandate the use of 1 mF supply bypass capacitors.

This circuit from AD202 Application