Soldering iron control (CB7961E)

This circuit was found in a 1992 Electronics Hobbyst Handbook. The circuit is for the 110 V power grid. The integrated circuit must have a heat sink.

Transistor Tester (CB4370E)
This circuit was found in an English magazine from 1979. The magazine no longer exists, but the...
Debounced Switch 7404 (CB3861E)
This traditional TTL anti-clock setting was found in a 1993 American documentation. The circuit...
Low Frequency Astable (CB470E)
The astable multivibrator shown by the figure can produce signals in the 10 to 10 000 Hz band...