This monostable circuit, from a 1977 Radio Shack documentation, uses a 7400. The time is given by the capacitor and the power must be supplied with 5 V.
This circuit safely replaces common locks, since, instead of the key, the opening is made with the...
This amplifier, common in 1986, uses a hybrid integrated circuit that can offer some difficulty to obtain...
This circuit, found in a 1979 documentation, consists of a small inverter that applies a voltage to...