Triac driver (CB22446E)

The presented circuit uses an optocoupler to trigger a triac. We found it in a Popular Electronics from 1992.

Rocket Altimeter (CB25357E)
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....
Band rejector active filter (CB7405E)
This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common...
Transistor test (CB22545E)
16 commercial test circuit for tubes and transistors appeared in Radio Electronics magazine in...