Triac Heating control (CB21372E)

We found this circuit in a 1966 RCA manual. The integrated circuit is unusual, and the Triac must match the load.

Temperature sensor shield (CB5093E)
This circuit was found in an old publication and can be adapted for use with modern...
Servo Test (CB11388E)
The circuit presented generates pulses at regular intervals with the duration controlled by a...
Volume Expander (CB19809E)
The LS150 is an uncommon high-performance operational amplifier today. The circuit is from old...