Using a 555, this configuration appears elsewhere on this site. This is from American documentation from the 90s. The indicator can be an LED or some device controlled by a relay.
This TTL circuit can be used as a shield, controlled by one of the inverters. The circuit must be...
This is the conventional astable configuration of the 555 integrated circuit already explored in...
The circuit shown in the figure can be used to connect a loudspeaker to an amplifier only after...