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

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Discussion Overview

The discussion revolves around the feasibility of using a 12V TV in an RV powered by a standard 12V vehicle electrical system, which can experience voltage fluctuations. Participants explore whether a voltage or current regulator is necessary for safe operation.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if a constant current or voltage regulator is needed for the TV, given that it operates on a 12V, 3.5 Amp input.
  • Another participant suggests that the TV might not be sensitive to current variations due to the specifications of the provided AC to DC adapter, implying the presence of an internal regulator.
  • A different participant emphasizes the importance of supplying a constant 12V within the specified tolerance and warns against operating the TV below its minimum input voltage, which they estimate to be around 10.8V.
  • One participant references a previous discussion about using DC-DC converters in vehicles to stabilize the 12V supply, recommending this approach for the original poster's situation.

Areas of Agreement / Disagreement

Participants express differing views on whether a regulator is necessary, with some suggesting that the TV may handle the voltage fluctuations while others caution against potential damage from insufficient voltage.

Contextual Notes

There is uncertainty regarding the minimum voltage tolerance of the TV and how it might respond to fluctuations in the RV's electrical system. The discussion does not resolve whether a regulator is definitively required.

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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