This circuit was found in documentation from the 90s. The operational amplifier is NE5514, which is uncommon today. The configuration can be adapted to use modern components.
This is an example of a temperature sensor shield using the Texas Instruments TMP390 obtained from...
This circuit, which appears from other sources in this section, allows you to control a load...
This is an experimental crystal radio that uses no power source. The antenna must be very long (at...