We found this circuit in an article that describes several alarms that are in the sequence in our section. The article is from the Radio Electronics magazine of May 1971.
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....