Temperature controller LM3911 (CB21281E)

This circuit is from a Popular Electronics from the 90's. The circuit provides an output for a control stage.

Field Strength Meter (CB13667E)
This instrument was found in a publication for radio amateurs in 1973. The tuned circuit consists of...
Current to voltage converter (CB5094E)
This circuit was found in an American documentation. Its purpose is to allow the use of a digital...
Temperature Sensor 741 (CB19388E)
The sensor used in this transistor is a common silicon transistor and the operational admits...