With an output power of 1.5 W under a 12 V supply, this circuit makes use of transistors that are still common today. Power transistors must be mounted on heat sinks.
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...