This circuit was found in an American documentation two years 80. The MOSFET is of double port, difficult to obtain now and the circuit has a tuning frequency determined by RC.
The circuit uses operations that are no longer common nowadays, as it is a configuration obtained in...
Foto-Darlington for applications such as light sensor. In normal applications only the collector and...
This relay shield circuit for old computers was found in January 1983 Radio Electronics magazine. The...