This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses a 556 as a modulator. Note the code programming key.
Found in a Popular Electronics from the 90s, this game can be seen in other configurations on this site. The...
With a 1 500 uFcapacitor this timer can reach times up to one hour. The capacitor must be of good...
This circuit appears in other articles in this section, but it is very interesting. It is a...