This circuit is from 1999 documentation. However, it can still be easily assembled, as all components used are common. The sensors can have their quantity increased, being connected in parallel.
We find this circuit in a 1973 technical documentation. Common transistors may be BC548 and FET or...
This 1992 circuit operates in the range of cordless phones used at the time. The circuit is based...
This traditional transistor source uses only two transistors found in a 1998 documentation. The...