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

Motorcycle 13.6V 3A charger
Negative Voltage from single positive power Supply
Wireless Doorbell
Model Railway Short-Circuit Beeper
CO2 Laser
LM4911 different power circuit conduction time recommended
Boost has a frequency characteristic of automatic offset MAX630 power conversion



Top