Active components are components of a power supply Belot, eg Operationsverstaerker or transistors.
The basic technique is an analog circuit
Analog technology means that any voltage level are processed.
This is a classic
Here you will find Schematic Circuit Diagram for DIY and further information on Remote Blocker
|Simple circuit with NE555||www.electronic-circuits-diagrams.com/funimages/funckt4.shtml|