"Mark" wrote in message
om...
small-LCD-screen flat panel TV, cable ready.

It'll run on clean 12.3 volts +-5%, but high voltages will burn out
the flourescent tube system which lights the screen, because there's a
stepup transformer for it which overheats at high voltages.

Indeed. Always use a 'whatever in' to 12V converter. I was involved on a
ship where 12 professional LCD touchscreens were installed. They were rated
for 24V and directly connected to the 24V power system (=batteries). Within
a few weeks, all monitor backlights failed. They couldn't stand the voltage
of a full battery (27-28V).

Meindert