Andy and TW may be on to something. Although the current itself might not be a problem (a 50a device is not that more expensive than a 5a one) the power dissipation will be.
The output triac will drop ~.7v (silicon device). Since power is amps times volts and the .7 volt dropped in the triac is fixed, doing this on the 12v side will mean the device has to shed 10 times what it would on the 120v side for the same light output.
I am still curious about what these wave forms look like. When the mob of kids and grandkids go home I will take a look.
