This circuit was obtained in an American documentation from the 80's. The transistors can be equivalent to those indicated and the crystal can reach a few tens of megahertz.
This circuit can be used as a control shield for microcontrollers of all types. The supply is made...
The figure below shows an AC transconductance amplifier with the National Semiconductor LM3900. The...
This circuit provides a good audio power from a signal at least 1 V of amplitude. The MOSFET must...