Bosch have a better system that doesn't destroy the blade or require the cartridge to be replaced every time because it merely retracts the blade very quickly into the bed, but SawStop are using their patents to stop Bosch from selling it. Apparently they went to the effort of patenting every possible approach that doesn't require the expensive but profitable single-use cartridge even though they have no intention of using them, just to stop competitors from doing it.

Looking at the system, it looks like even Bosch needs to replace some components after the safety system kicks in.

Yes, the explosive fuses at $1 a pop. It could be improved to use resetable fuses but those are slower. There is a safety trade-off here.

People tend to sue when their patents are violated.

Like it or not, that's the point of obtaining a patent.

As horrible as patents are, this seems like an abuse even if the patent system. I think all patents should expire no more than five years from application date or one year from certification date whichever is longer.

This is true, it does trigger with wet wood. Aside from framing lumber (2x4s, etc), most woodworking is done using kiln-dried hardwood, though.

I worked around a sawstop at the Stanford student shop for a couple of years, and saw it triggered a handful of times: once was a piece of mirrored acrylic, once was a (wet) oak stump, and once was a TA's finger (he was fine, just a nick).

We frequently turned the safety off if a student needed to cut something that we knew might trigger it - it's just a key that you turn next to the start/stop switch.

The blade is not always ruined - just depends on the blade you're using. We primarily used a blade with carbide tips (which is very common, though more expensive), and I never saw the blade ruined.

Personally, I would never buy a table saw without this technology. However, I'm not sure we need a law to require it.

It would be neat if they had a "test zone" where you could hold the material against to see if it was conductive.

There should be a mode you can touch the wood to the blade before it's spinning and it will tell you if it's damp enough to trigger it.

You're assuming the moisture content is equal across the work piece. It's not.