It's probably just his DC power supply he has handy.
As far as 120/240 thing, if you have a component not meant for that kind of voltage, it might fail open, or it might fail short.
If it fails short, high amounts of current might be allowed to flow through other components which would carbonize so even more current would flow. And maybe catch fire.
As far as 120/240 thing, if you have a component not meant for that kind of voltage, it might fail open, or it might fail short.
If it fails short, high amounts of current might be allowed to flow through other components which would carbonize so even more current would flow. And maybe catch fire.