This 12 V x 2 A regulator was found in 1965 Delco Radio documentation. The circuit uses transistors from that time. The input voltage can vary by 15% around the indicated value.
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
This circuit transmits the audio signals from a telephone line to an FM receiver placed nearby. The...
This circuit is from an old manual of operational amplifiers. The setting can be adapted to work...