BeeCNC Power Supply

The BeeCNC uses the salvaged 7V EPSON steppers, which draw about 0.7A each. I found a datasheet on wrobots. To power everything correctly, considering the unusual 7V requirement of the motors, I designed a little power supply board myself.

To power each motor at its ideal voltage, each gets its own LM317 adjustable voltage regulator on the power board. The power board also includes a 7805 regulator for the 5V logic. It has a power switch, a big 6A diode for reverse-polarity protection, and a 5A fuse to prevent fires. Discounting the router itself (which plugs directly into the wall), the BeeCNC shouldn’t draw more than about 2.2A.

I decided to keep the power board separate from the logic to avoid complications in debugging and to keep the modularity of the design. Using two boards also frees me from making a whole new board, when the logic board I have seems to work fine so far.

The Schematic

The Layout

The Files

BeeCNC Power Board Files (v1) (.zip)

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