This circuit was obtained in the Philips integrated circuits manual of 1990. The indicated power is 14.4 V, and the power depends on the load that can be between 2 and 16 ohms.
This different alarm system, found in an old publication, uses the starter chain to protect the...
We can implement this circuit from a 1994 publication using BC548 and BC558 transistors. The...
Found in an English documentation, this circuit provides a 50 Hz signal according to the local...