Switch with automatic shutdown (CB21258E)

This circuit was found in Maxim documentation from the 1990s. The RC circuit determines the trigger time.

Operational RIAA Preamplifier (CB14846E)
Common operational amplifiers like the TL series, CA3140 and others can be used in this circuit...
76 dB Gain Preamplifier (CB25695E)
This high-gain amplifier was found in the March 1994 issue of Electronics Now magazine. The...
Process timer (CB21865E)
We found this timer for times of a few minutes in a 1974 Ferranti transistor manual. The relay is 37...