Making A LED Chasing With NE555 And CD4017

Overview Of NE555 And CD4017

In an earlier post, I use NE555 to blink a two-color big LED. Now I use the basic building block used in that post to make a slow variable clock source that fed to a CMOS counter CD4017.

In digital circuit terminology, CD4017 is considered as a counter or a frequency divider for digital circuit, or a micro-processor. In every day usage especially for an electronic hobbyist and LED lighting, this IC is widely use for LED chasing due to its easy to use, without any programming.

These PCBs soldering, I made for a high school technical electronics class a year a go.

Copper soldering sides, I coat them with clear acrylic paint to protect them from
corrosion and a little shorted circuit.

Last year I made these simple electronics stuffs to attract high school student in studying with technical electronic class. They work well without errors.

I bought a few 4017 devices from online store for my personal use. The device typically supplied at 5 V for hobbyist prototyping.

A pair of CD4017 at my workshop

Pin Diagram from Fairchild device datasheet.

Timing diagram. The outputs is chased gradually due to the number of clock pulses.

Schematic And PCB Design Of CD4017 LED Chasing

I make a circuit drawing and simulation in the simulator. So it's ready to draw the schematic diagram and PCB design for outside use.

Schematic Diagram

U1 make a clock pulse fed to the CLK pin of CD4017. The clock pulse varies in a  range of milli seconds by adjusting to POT RV1.

The system is regulated by 7805 +5 V voltage regulator. From Q0 to Q9 are the ten counting output while CO is the overflow flag. It's set whenever the over-lap of Q9 counting is made.

A completed PCB design

Copper Pattern

Component Side Top Silk

A 3D Model Of The PCB Panel

To download the complete design file click here.

 

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