This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
This circuit causes an LED to blink from the 1.5 V supply thanks to the use of a voltage doubler. The...
This circuit uses a dual floodgate MOSFET not very easy to obtain today. Its handling is very...
This simple circuit was found in an old documentation. The transistor can be changed according to the...