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In todays article, I will show you running lights based on three popular microcircuits: an operational amplifier microcircuit LM358, a timer microcircuit NE555, and decimal counter microcircuit CD4017.

The running lights schematic diagram and printed circuit board (PCB) were developed in Easy EDA online environment.

The device schematic diagram consists of four parts, such as a microphone amplifier, an impulse generator, a ten-digit counter and LED indicators.

This device works in such a way that the microphone signal, after amplification and smoothing, is converted into a voltage with level proportional to the signal amplitude. This voltage is applied to an impulse generator based on the microcircuit NE555. Then the impulse generator signal arrives to the input of the ten-digit counter CD4017.

The counter microcircuit has ten outputs, six of which are connected to LED modules of different colors. Each individual LED module consists of thirty-seven LEDs.

Based on the schematic diagram, we get a double-sided printed circuit board. SMD components will be mounted on the one side of PCB, and LEDs, trimming resistors and a microphone on the other side.

Also in the online Easy EDA environment there is a 3D model preview, which allows you to view the future PCB from different angles.”

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