Found in documentation from the 90s, this circuit triggers a relay with inductive signals applied to a link. The sensitivity depends on the frequency and the power supply depends on the relay used.
We found this circuit in a 1998 documentation. The circuit can be made with 12 V, 6 V or even 5 V...
Avago Technologies (www.avago.com) suggests the circuit in Figure 9 for amplifying signals of...
This circuit was found in the April 1970 Radio Electronics magazine. The dual function circuit uses 4...