Used the LM2577 output voltage for the supply voltage and used one of the other outputs to feed the feed the cap. It doesn't get much more stable than this.
Dsy5 warned me about using the output to stabilize the discharge since it is basically a short to ground when making the weld, and the documentation agrees "Note 5: Short circuits from the output to V+ can cause excessive heating and eventual destruction. When considering short circuits to ground, the maximum output current is approximately 20 mA independent of the magnitude of V+."
So since the drain to the cap is so minimal without it, I'm not going to use the second output to the cap.
The
threshold voltage needs to be at least 1v or more, less than the input voltage. So I will just set it up that way.
I might use a second output with a lower
threshold with an amber LED to show charge and the red LED threshold at ~1v lower than the input. That way I know if it is charged but more than 1v less than the LM2577 so I can just recharge the cap via the charge button.
Now I just need to round up a bowling ball, slide, and some dominoes
