This circuit that draws 1 out of 8 LEDs was found in an 80's American documentation. The circuit can also work with an astable using the 555 instead of the 4046 which is not a common component today.
April 2017 - The new Maxim Integrated MAX20733 and 20745 switched regulators are available from...
The indicator for this circuit is a mini buzzer with a 1.5 V oscillator. The circuit can also be...
This 80's documentation circuit includes an amplifier of the era. Used integrated circuits are...