This circuit was found in a Popular Electronics from the 90's. The transistors are general-purpose types and the loaded load depends on the voltage and must have a maximum current of 100 mA.
This circuit was obtained from an English magazine from 1985. The N414 is a complete, not easy to...
Found on Popular Electronics from 1969, this circuit can be implemented with components that are...
This circuit is from a book of transistors from 1954. The transistors are from the time and the...