Can I Use My 12V TV in My RV Without a Regulator?

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SUMMARY

The discussion centers on using a Magnavox 15" LCD-TV (model 15MF400T/37) in an RV's 12V deep cycle electrical system. The TV requires a 12V, 3.5A DC input, and while it is suggested that the TV may have an internal regulator, it is crucial to maintain a stable 12V supply within the specified tolerance to avoid potential damage. Users are advised against operating the TV below its minimum input voltage, estimated at 10.8V, to prevent issues with the backlight power supply. The recommendation includes considering a DC-DC converter to ensure a clean and stable power supply.

PREREQUISITES
  • Understanding of 12V DC power systems
  • Knowledge of voltage and current specifications
  • Familiarity with DC-DC converters
  • Basic electronics principles regarding power supply
NEXT STEPS
  • Research DC-DC converters suitable for automotive applications
  • Learn about voltage regulation techniques for sensitive electronics
  • Investigate the specifications of automotive power adapters for similar devices
  • Explore the implications of voltage drops in DC power systems
USEFUL FOR

RV owners, electronics enthusiasts, and anyone looking to integrate 12V appliances into mobile power systems.

turner7A8
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I've recently purchased a Magnavox 15" LCD-TV {15MF400T/37}
which requires 12 volt, 3.5 Amp, DC input.
I want to use this TV in my RV - on a Standard 12 volt,
Deep Cycle, Vehicle Electrical System - where voltage can
vary from 10 - 15 volts depending on the state of discharge
or recharge, etc.

Will it be necessary to regulate the current input (to the
TV) with a constant current regulator, and/or voltage
regulator ??
Or can I just plug it Straight IN ??
Thanks,
turner7A8
PS- The TV came with a 120 V. AC to 12 V., DC, 4.16 AMP
converter and there's no documentation regarding vehicle
usage and Magnavox Support says there's no accessory for 12
volt DC to DC operation.
 
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It seems as if it isn't terribly picky about the current if the adaptor is that far off of the input specs. Maybe there's an internal regulator. I wonder if you can't just find an automotive adapter with the same specs, such as for a Gameboy or portable DVD player. They use LCD screens as well, so their specs must be somewhere in the same neighbourhood. Try asking a local TV repair shop.
 
Don't confuse current and voltage. The TV will have an input voltage requirement that should include the tolerance on the 12V input. When you supply the 12V input as required, some current will flow, and the maximum current that will flow is the 3.5A number that you mentioned. The TV will likely draw less than that maximum current most of the time. But your job in providing power is to be sure to supply a constant 12V (at least within the specs tolerance), and be sure to be able to hold that 12V even while supplying up to 3.5A. A constant current supply is a totally different animal.

Having said that, I don't think it's a good idea to run the display below whatever its minimum input voltage is. Most likely, it's something like 12V-10% = 10.8V. If the supply drops below that minumum, I'd imagine that some bad things could happen. Like the EL backlight power supply might start to have problems...?
 
BTW, I thought I remembered an old thread where we talked about running 12V equipment in cars (where you need a better 12V supply than the car battery circuit provides). I used the PF search engine to find it. Check out my post part-way down the thread, where I found DC-DC converters for cars that clean up the 12V. This looks like the way the OP should go:

https://www.physicsforums.com/showthread.php?t=109271
 

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