This circuit has a correction or linearity adjustment. We found it in Ferranti's transistor manual from 1974. Transistors are general-purpose types at the time.
This configuration is from a 1987 publication, but it can be easily assembled today, as the...
This circuit was obtained in a technical documentation from the 70s, but it can be assembled with...
This circuit triggers a load when the sensor detects humidity. The triggering point is adjusted by...