Found in an Electronic Design from the 80's, this circuit uses components from that time. He has outputs for activating 8 solenoids from a microcontroller.
This circuit was found in a 1995 documentation. It drives a set of sequential LEDs from the sound...
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...
The integrated circuit used is equivalent to the 555 and the transistor can be the BC558. R1 and...