This circuit for old analog telephones is from period documentation. It controls a relay that can be used to turn the extension on and off.
August 2017 - MCUs of the new Infineon MC1400 series for industrial use can now be purchased from...
In this circuit, the output voltage is Vxx plus the zener voltage. The circuit is from the SGS...
This circuit can be used in traffic alarm systems. The relay trips when the light falling on the...