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 SCR relaxation oscillator was found in an 80's Electronic Design. It flashes a small...
The coils for this transmitter, found in a 2002 documentation, have the following characteristics: L1 - 4...
This dimmer configuration is quite old, as it was found in a 1967 publication. The triac can be of...