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.
In the figure we have a classic Clapp oscillator configuration for a frequency of a few tens of...
This circuit takes advantage of the inductance of the phone in the resonant circuit. The circuit is...
In the figure we have the way to increase the voltage of a 78xx by adding a zener diode. The...