This circuit was found in an Electronic Design from the 90s. The circuit uses a type J thermocouple that can measure from -50 to + 100º C. Power is provided by a 3 V lithium battery.
The critical components of this 1978 circuit are transformers, which, hopefully, can be obtained from...
Found in a manual of integrated circuits from the 90s, this circuit makes use of that time...
This tuning-free circuit was found in an old operating amplifier manual. The setting can serve as...