I've decided to build the CNC Etch-a-Sketch instead of the miniature lathe. Hopefully this will stop people from telling me over and over that I wont be able to make precision cuts etc etc which I am fully aware of. The novelty factor jumps up a full ten points by making a cnc etch-a-sketch versus a tiny machine tool. Plus it frees up a bunch of erector set pieces for other projects, one of which will be a stirling (heat) engine. Anyway, here are my questions.
I'll be driving each axis with an
NTE2018 8 channel darlington array IC. Of all the variations of this project found online, this is the only one that can be controlled with standard G-Code via Linux EMC. With such a simple driver cicuit that is. Below is my schematic.
**broken link removed**
Question one. If pin 10 is the common cathode, how come it's connected to VCC? If I understand, this is where electricity flows
out of a diode, why then would I attach that to a hot line? Obviously it's because I don't know ****.
Question 2, it calls for a 16V 1000uf capacitor. Actually I got the voltage from the picture, it wasn't specifically asked for. I don't have one, all I have is an assortment of ceramic disc capacitors. They all just have an underlined number written on them and nothing else. No n,u or p...nothing. Can I use a ceramic type instead of the can type if the value is the same? Can I hook up 10 100uf discs in series for the same effect? How impotant is the voltage rating?
Question 3. I would like to add an indication led for each axis. My thinking was just add a resistor and led in series between pin 9 and ground, one for each IC. How do I determine the value of that resitor? Will that even work? If not, what will work and why.
Thanks guys, I can't say thank you enough for taking the time with such simple, trivial ****.
PS The magic smoke analogy is still cracking me up,