In the figure we have the way to obtain 500 gain from a FET. FETs can be BF245 or MPF102. The circuit is from the 1977 National Semiconductor FET Data Book. Power supply depends on the application.
This watch was found in 2001 documentation. The watch is powered by 4 batteries. To save energy, the...
This circuit is from Motorola's Linear Databook from 1990. The integrated circuit and transistors are...
This is one of many possible touch switch configurations using CMOS integrated circuits. The...