Found in an American documentation from the 90s, this circuit uses small low voltage lamps (6 to 12 V0. The circuit can be adapted to use LED indicators.
Found in a 1970 EEE, this circuit can be applied to TTL ports. The supply is 5 V and the...
This circuit is from a 90s Popular Electronics. The integrated circuit is from that time. The...
This automation control circuit uses two relays to control 4 loads using just one switch. The...