This anti-bounce circuit was found in a 1967 US documentation. Modern transistors such as the 2N2222 can be used. The circuit acts as a shield.
This circuit uses a Hall device from that time as a sensor. The circuit is from an English...
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This audio generator that produces both rectangular and sinusoidal signals was found in a...