This circuit was found in the February 1971 issue of Radio Electronics magazine. It is designed to power the previous circuit, providing a maximum current of around 50 mA.
This amplifier uses common transistors in a phase inverter configuration. Transistors must be...
This is the same amplifier circuit as the previous circuit adapted to operate with a single...
In fact, this 1994 circuit uses a scale of LEDs to indicate the pulse rate applied to its input....