This touch switch uses components that have easy-to-obtain current equivalents. The power supply must be isolated and the cable to the sensor must be short.
Found in a 90s Popular Electronics, this circuit is interspersed between the filter and the...
This circuit is from an 80's documentation. The integrated circuit is from the time and the...
This circuit was found in a 80s American documentation. The zener diodes determine the points of...