Touch Switch with MPF102 JFET


Posted on Apr 22, 2012

When the touch plate is contacted by a large object (human body, etc.), stray 60-?? pickup is rectified by D1 and D2, and produces a negative voltage across R2-C2 and the gate of Q 1. Q1 cuts off, causes Q2 to conduct, and the output goes low.


Touch Switch with MPF102 JFET
Click here to download the full size of the above Circuit.

Q2 is held cut off since Q1 normally is conducting.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

450 watts / 3.5-30 MHz Linear amplifier
Frequency limit detector
200Ma-12v ni-cad battery charger
Ujt-battery-charger
12-Vdc-battery-operated-120-vac-power-source
Rain Sound Generator Using NE555 PCB
555 timer Clap switch circuit electronic project
LED sequencer
ISL6291 Li-ion/Li Polymer Linear Battery Charger
Simple Under-Voltage Cut-Out
V3.0 MS Build With Pics
MP1826 by the LM567 and precision timer circuit



Top