Using a 74123 TTL this circuit was found in the Radio Elecronics magazine of June 1975. The power supply must be 5 V. The capacitor determines the activation time.
This circuit was obtained in a 1975 documentation. It is intended for old vehicles that still use...
This circuit uses a diode as a radiation sensor. The operational ones are old because the...
This circuit was found in the March 1999 issue of Electronics Now magazine. The meter is analog and...