This 13 A V power supply with 2 A uses a transformer with 12 V of secondary and 2 A of current. The diodes can be 1N5404 or equivalent for 2 A or more.
This circuit was found in a 90s Popular Electronics. The sensor can be any phototransistor. ...
Indicated for the protection of three-phase systems, this circuit was found in an American...
This circuit was found in a 1969 Motorola documentation. The FET admits an equivalent. The circuit...