Collector, emitter, base

18 March, 2012

You can keep your green hat, your sticky beer and your “weaaaayyyy” noises. All I need for a happy St. Patrick’s Day is an Arduino, a breadboard, some transistors and resistors, a diagram or two, some stolen heatshrink, oh, another breadboard, some borrowed diodes, some datasheets, some more transistors, some code…

…hey, my tea’s gone cold…

Why so many wires for such a simple thing? The slicer is a straightforward motor and limit switch, but I wasn’t sure what kind of motor drove the rollers. Guessing that it was a stepper motor, I decided to build a stepper motor controller and see if it worked. So, most of this mess is a dual H-bridge, and having confirmed that it is indeed a bipolar stepper motor, I can replace the whole thing with, say, one of these.

A nice side effect is that I’m fourteen transistors closer to understanding transistors. They only have three legs, why is this so hard?

And what is this for? Like most of the things I do that have no obvious purpose, this has something to do with That Thing In The Desert.


  1. That’s my girl! Transistors are similar to valves (vacuum tubes if you must) but without the excitingly high voltages….

    • Then I will stick to transistors for now, if that’s all right with you 😉

  2. […] a grand blog « Collector, emitter, base Prototyping 19 March, […]

  3. Make sure you tell your fans how you’re going to use several hundred small paper rectangles. We’re opening a book on it over here. – Thos

    • The strips of thin rectangles have been used to give the suggestion of eyelashes to a couple of lamps, and the larger rectangles got recycled into a shopping list because the iSlate is still on the Shelf of Shame.

  4. […] Reinstated the slicer. Getting the slicer to slice was straightforward (it’s just a motor) but getting it to stop reliably in the right place was not. It slices at […]

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