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.
In the figure we have a sensor circuit that makes use of common transistors and a photo diode as...
This unusual configuration, but which has already been explored in other articles, uses diodes in the...
This circuit uses a modulated signal from a PLL 567 to operate safely with an infrared emitter. The...