====== current goal ======

We're trying to build this circuit.  So far, we're just trying to build the 555 portion,
and test that it works properly.  After that, we'll hook up the MOSFET, back EMF protection, and
ignition coil.

                http://www.penguinslab.com/Pictures/Ignition%20coil/Schematic.JPG


====== findings ======

- most of our 555's are blown       (why?)

- our 555 tester is good, it seems to work in some cases, but we're not confident enough that it
  works in all cases, which means we can't rely on it at all yet

- probing (with a multimeter) at all pins of the 555, it LOOKS like most of the voltages are fine,
  but that the output doesn't seem to vary at all.  It's hard to tell though, because for these
  selection of components the frequency varies from 170 kHz to 1.8 mHz, which is completely outside
  the range of human hearing.
        http://www.google.com/search?q=1%2F(.693+*+(11000+ohms+%2B+11000+ohms)+*+390+picofarad)
        http://www.google.com/search?q=1%2F(.693+*+(1000+ohms+%2B+1000+ohms)+*+390+picofarad)




====== things to do ASAP ======

- order from Digikey:
    - a bunch more 555's
    - any other components needed for a 555 tester
    - 2 or 3 more 390pF capacitors for this circuit:
                http://www.penguinslab.com/Pictures/Ignition%20coil/Schematic.JPG
    - more of the MOSFET and back-EMF protection bits from this circuit:
                http://www.penguinslab.com/Pictures/Ignition%20coil/Schematic.JPG



====== things to do next time ======

- bring ALL of my electronics home, particularly:
        - ALL breadboards
        - ALL multimeters

- I need to figure out a methodical way to "debug" electronic circuits, like the way that I approach
  a software problem.  This scattershot approach doesn't necessarily work.
    
    - if I had money, it would probably involve an oscilloscope.  Since it doesn't, maybe we can
      improvise a little bit?  Instead of using a function generator, use a potentiometer, so we can
      slowly control the waveform as we put it through its paces?


- hook it up to xoscope (Linux) or Zelscope (Windows) up.  However, as the zelscope FAQ notes,
  soundcards can't ever measure DC voltage


====== things we need to buy for next time ======

- LOTS of 555 ICs -- we blow them CONSTANTLY for some reason

- TWO more breadboards -- we HAVE to be able to set up separate circuits, for two reasons:

        1. to test that a given component is working   (particularly 555's)

        2. to isolate and simply a smaller part of the larger circuit, to play with it and make sure we understand what it does