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.

Photodiode Amplifier (CB15651E)
The gain of this circuit is given by the value of R1 that depends on the current in the...
3 transistor radio (CB18405E)
This receiver, called Peace, was manufactured in the 1960s in Japan and was powered by a 9 V...
Digital Timer (CB3808E)
This circuit was found in a 1987 publication. A 4017 sequentially counts time in steps set by...