I am not sure what you mean by an AC DC TV. Many TVs of that size use an external power supply that converts the AC to some lower voltage DC. These are not advertised as AC DC but work well without the external power supply.
If you make sure the external power supply has an output of 12 VDC, usually marked on the supply, then the TV will work on 12 V without the external supply.
I have used a 22" TV that came with an external supply. I took the external supply off and connected the TV to the 12v power. Be aware that there may be a risk of doing damage to the TV if your 12v supply gets too high.
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