Blimp Aerial Photography Timer Success!

The other day I posted about progress on an aerial photography project.  At the end of the day, my auto-picture-snapping circuit didn’t work.  It’s my first project using a 555 timer (NE555P).  I finally measured the capacitance of the timing capacitor and found it was WAY smaller than I’d thought.  The circuit output seemed to be always high because the frequency was really high.  This also explains the low voltage (averaged over duty cycle)!  I swapped the capacitor with one closer to my design and it flashed LEDs just right!  When I connect the camera up to the MOSFET (2N7000) that is controlled by the output of the 555, I got pictures!  Woohoo!  You should have seen my excitement when it finally worked…actually you can!