We found this circuit in the Philips integrated circuits manual of 1990. The circuit must be powered by a symmetrical high current source. The integrated circuit must have a good heat radiator.
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...