I stumbled upon an interesting characteristic of the SSG: it emits audio even when
not in self-oscillation mode!
And since the waveforms (attached below) are fairly uniform, this means I can use it to measure RPM without a tachometer.
BTW, I acquired a real, though quite dead, lead-acid battery that had been sitting in a rusted out old riding lawnmower for who knows how long. After I cleaned it up, I checked the electrolyte levels (still fairly high) and the voltage (half a volt). I built a new rotor and got some MJL21194Gs and finally got around to adding the second coil. After about eight rounds or so of charging and discharging, that sucker has come back to life! Yeah, I know, same old boring story.
Still, it's one thing to read about this stuff and quite another to see it for yourself.
So far the load times have been going up; it'll be interesting to see how much it comes back from the dead.
The other two coils are just waiting to be put in. Now it's just a matter of finding a block of time to install them and their associated circuits.
I'll post pictures soon...
For those who want to know: The battery is a 12V/230CCA lead-acid type. I'm loading it with a 25W light bulb through a 350W inverter. Load times are currently over an hour. Simply amazing for a battery that couldn't hold a charge a couple of weeks ago.