capacitive probe circuit - Búsqueda para electrónicos

If the unit is brought close to a live conductor (insulated, and even buried in plaster) capacitive coupling between the live conductor and the probe clocks the counter, and causes the LED to flash 5 times per second, because the 4017 IC divides the mains 50Hz frequency by 10. When remote from a live line, the unit stops counting, the LED resulting permanently off........

http://www.circuit-finder.com/categories/tools-and-measuring/current-and-voltage/739/live-line-detector-indicator-circuit-schematic

https://bestelectronickit.blogspot.com/2010/08/vhf-oscillators-for-overtone-crystals.html

http://electronics.dapj.com/search?updated-min=2008-01-01T00:00:00%2B05:30&updated-max=2009-01-01T00:00:00%2B05:30&max-results=9

https://felicinwiring.blogspot.com/2013/04/preamp-stage-for-ceramic-phono.html

http://dangerousprototypes.com/blog/2016/04/26/capacitive-battery-charger

A high quality broadcast stereo transmitter for the FM band

http://www.ludens.cl/Electron/fmtx/fmtx.html

http://www.cappels.org/dproj/lowcapadap/LowCapProbe.html