Temperature controller LM3911 (CB21281E)

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

Resistance Multiplier (CB21114E)
This circuit multiplies the input resistance of an operational amplifier. As the indicated...
MOSFET Power Stage (CB980E)
This circuit provides a good audio power from a signal at least 1 V of amplitude. The MOSFET must...
Magnetic field meter (CB7061E)
This sophisticated circuit using a liquid crystal display was found in Radio Electronics from the...