Originally Posted by Birdmaestro
My 22" Samsung has a power supply that I assume is just a transformer that steps down the current from 120v to 12v. It seems like a lot of extra shakin' and bakin' to use an inverter: start with 12v => convert to 120v => convert back to 12v. I'm wondering if I could just cut the cord before the power supply and splice in a 12v plug?
It may not be dropping to 12v. My Sirius satellite radio has a power supply on the plug that provides a voltage other than 12v, like 7.5 dcv. It's under the dash now so I'm not sure what it actually is. The inline power supply should have the in / out voltages on it. There may be an aftermarket adapter to replace the wire without having to cut off the plug. If you provide the wrong voltage you can do serious damage.
I use the inverter for other things too, that car doesn't have a built in inverter so I use this one to power the TV or charge the laptop batteries. The older TV I have came with a 12v cord but the new LCD didn't. I already had the inverter so I just use it.
Most TVs, radios etc. run on voltages other than 120 VAC, but the transformer that drops the voltage is inside the unit and it expects 120 VAC. If you have an external transformer there should be a data sheet on it telling you what the voltages are. You can always go to the manufacturers site for more information. I wouldn't recommend cutting off the plug.