This circuit was obtained from an American documentation from the 90's. The components can be changed, and a power step can be added for greater sound volume.
This 1986 documentation circuit provides 3, 4, 5, 6 V voltages under 350 mA for powering walkmans...
This circuit is characterized by the configuration that accelerates the switching, being ideal for the...
These circuits use loads of 50 ohms to allow the use of a voltmeter in evaluating the output of a...