Matthias Wandel came up with a wonderful solution to making accurate cuts on his table saw. Best of all this system was built from scrap parts from a junk bin. Watch the video to see this cool machine in action. Make sure you check out the rest of his wood working tips, tricks and projects here.
"Going through my junk bin, I found a circuit board with 11 power transistors on it that suspiciously looked like it might have been used to control a stepper motor or something like that at some point. Working out the schematic from the traces, it was almost what I needed for my purposes. I cut out the part of the circuit board with the transistors and a few logic chips with a Dremel tool, changed the wiring of the diodes on the board to act as catch diodes, and soldered a printer cable to drive the logic side. Then I started playing around with hooking up stepper motors to that board."
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Matthias,
can you supply more details on use of incandescent light-bulbs for current limiting???
IE; Watt wattage equates to what equiv resistance and what Voltage you’re running your steppers at???
Thanks!
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I’m running the circuit around 40 volts, and the bulbs are 100 watt. That worked out fairly well.
One thing to keep in mind is that the light bulb’s resistance changes quite a bit as they light up, so rather than measure them with an ohm meter, put the expected voltage in them and measure the current.