We found this circuit in an Electronic Design from 1965. The 4-layer diode is an unusual component these days and can be used in its place with a diac.
We found this active crossover in a Radio Electronics magazine from June 1961. Note the different...
Found in Popular Electronics from the 90s, this circuit serves to indicate the output level of a...
If you are on an old PC that you use for experiments, control or other applications, this circuit is...