This circuit was found in a 1980s Intersil documentation. The integrated circuit used is not common today. The power supply must be symmetrical.
The simple circuit doubler shown here can source a voltage two times the one applied to the input. The...
This Power supply is intended to Power small loads with currents up to 30 mA. The voltage depends...
This circuit works only with carbon microphones, due its low impedance. The speaker should be good or...