Tell us about yourself!
Phillips and Pozidriv screw heads are designed to "Cam out" the screwdriver tip when they get tight enough (fine if you stop the instant it jumps out, bad news if you have a powered screwdriver and continue to press down hard)JIS doesn't, it has a "squarer" profilewhich is less inclined to slip - now it's undelniable that JIS screwdrivers are very much better for JIS screw heads (than ordinaryt screwdrivers), but I *have* used them on non-JIS stripped crosshead screws with some sucsess, although I can't guarantee it would work in each and every occasion.It's probably a case of "try if you happen to have a JIS screwdriver handy, probably not worth buying one specially"
Not all cross-headead screws are the same - For many years I ranted about how Japanese motorcycles used screwheads that must be made of "cheese" - turns out they were made of exactly the same stuff used in the west, only they were cut to a slightly different specification! If you are getting nowhere with your screwdriver, and on closer inspection you see a "dimple" on the screwhead, you need a "JIS" screwdriver - even a half ruined one becomes remarkably easy to extract with the correct tools!
If you have a *really* old head unit - with no Aux input and a "proper" analogue volume knob, that can often be the starting point for feeding a signal
Very smart! - I appreciate the simple design of the legs, but I'd be tempted to build something which folded flat, had a spar at the bottom of each pair running front-to back, and a rope across the way to stop them spaying if anyone was drunk enough to climb on the table!
Could you put several of these in series to get, say, 30v, with suitably uprated transistors? That would allow floodlight diodes to be used, but the current would be pretty hefty.