This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses a 556 as a modulator. Note the code programming key.
An interesting type of sensor for specific applications is the sensor formed by piezoelectric...
This circuit is from Radio Electronics from the 90s. It supplies a voltage between 800 V and 2 000...
This circuit was obtained in a 1989 publication and is quite simple to assemble, but critical in...