how much voltage fluctuation can a TV take.

[nofuss]

Hi all

I decided to install a LCD tv in my cabin and then noticed that some of the LED varieties use converter boxes to convert the 120v Ac supply to 12V dc.
as such I decided to get an LED LCD TV/DVD combo for my boat. and the plan is to use it with a cigarette lighter style connection for the 12V supply.
However, i was wondering if I stand a high risk of damage to the TV unit from the regular fluctuations we get in our battery voltage, like about 13.5V when the system is charging the batteries, or the possible draw down, if the engine is started.

any body have an idea on this. Or does any body know of a low cost idea for regulating the power supply to the TV with out too much power loss.

i believe that there would be a lot of power loss using inverter then converter. to go from 12v to 12v

Any info would be greatly appriciated.

No Fuss

 

[Lyle29464]

Re: how much voltage fluctuation can a TV take.

I would use a house battery to operate everything but the engine.

 

[dockwrecker]

Re: how much voltage fluctuation can a TV take.

You need to realize that 120v constant AC to a transformer will give a steady 12DC output. I'd doubt most TVs have the ability to take surges since it's relying on the conditioned 12vDC unless it's designed for automotive use. Check with your local car audio shop. they put TVs in cars all the time now, it can't be that hard.

 

[nofuss]

Re: how much voltage fluctuation can a TV take.

I plan to use a seperate battery for the house, however for charging if out for a weekend or something I plan to wire it so that it could be paralelled to one of the engine batteries. I dont plan to use the tv when the boat is running either, however u never know when that plan will fail.

No Fuss

 

[Jeep Man]

Re: how much voltage fluctuation can a TV take.

Add an in-line 12V regulator and surge suppressor between your power source and the TV. Available at most electronics suppliers.

 

[wire2]

Re: how much voltage fluctuation can a TV take.

The user manual that comes with the TV will state what the allowable min/max supply is.
+/- 10% is usually no problem.

 

[SigSaurP229]

Re: how much voltage fluctuation can a TV take.

When I drove a truck I worried that there may be a problem. I had a 13 inch tv DVD combo running using a 400 watt cigarette lighter power inverter never had any problems but be aware that it willl draw your batteries down quickly. Also you can look at truck stops and most will sell a direct 12v TV DVD combo as well. Also the power inverter will have a kill switch on it so that you can just turn it off totally and not have to worry about current getting to the TV with the motor running.

 

[nofuss]

Re: how much voltage fluctuation can a TV take.

Jeep man

that is the type of thing i was thinking about, however i am not able to locate anything of the sort. the only one that i have seen is for an rv and it cost about twice the TV, it would be cheaper to buy an additional battery, and just accept the inverter wastage.
do u know the name of any such item, or any supplier that may cary such.

Thanks
No Fuss

 

[Jeep Man]

Re: how much voltage fluctuation can a TV take.

Jeep man

that is the type of thing i was thinking about, however i am not able to locate anything of the sort. the only one that i have seen is for an rv and it cost about twice the TV, it would be cheaper to buy an additional battery, and just accept the inverter wastage.
do u know the name of any such item, or any supplier that may cary such.

Thanks
Look at electronics component suppliers. Fairly easy to McGyver what you need. Check out alarm and video surveillance suppliers. I use these items regularly and get them from the local alarm suppliers. Most alarm and video run on 12 volt DC.

 

[dvandsm64]

Re: how much voltage fluctuation can a TV take.

being an electrician i'm certain a tv meant for a.c. should be hooked to a.c. no matter what the small transformer on the cord says. a ac/dc tv is meant for both!
but an a.c. tv plugged into an d.c. invertor should be fine. the invertor is a rectifier(converts ac to dc) and probably a voltage regulator.

 

[Jeep Man]

Re: how much voltage fluctuation can a TV take.

being an electrician i'm certain a tv meant for a.c. should be hooked to a.c. no matter what the small transformer on the cord says. a ac/dc tv is meant for both!
but an a.c. tv plugged into an d.c. invertor should be fine. the invertor is a rectifier(converts ac to dc) and probably a voltage regulator.

Not so. Most flat screens work from an AC/DC adaptor, the same that runs your laptop. By using an inverter you are going from DC to AC and back to DC.

 

[mike343]

Re: how much voltage fluctuation can a TV take.

The user manual for your TV will give the allowable voltage limits for the unit. Some marine units are rated for 12 to 30 volts--they have an internal inverter anyway.

 

[Sixmark]

Re: how much voltage fluctuation can a TV take.

In all honesty, all of the TV's out there actually run on DC, the problem is that alot of people don't know it. The AC cord from your standard home television goes inside the TV to a power supply (which converts AC to DC) which then supplies DC voltage to the circuit board.

Anyhow now that we have that out of the way, your Combo TV sets that come with a DC (cigarette lighter) plug on them are actually constructed to handle up to 14 volts DC, because in theory this is the relative max that an alternator on your RV or car should put out (if it is functioning properly).

The regulator is an excellent failsafe and is the only way to go when using it in a marine application.

 

[bruceb58]

Re: how much voltage fluctuation can a TV take.

the invertor is a rectifier(converts ac to dc) and probably a voltage regulator.

No its not. An inverter converts DC to AC. You are an electrician?

 

[bruceb58]

Re: how much voltage fluctuation can a TV take.

A regulator for something like this is going to run over $100. Its actually a DC/DC converter because it has to step up the voltage and then regulate it down. The problem with regulating to 12V is when the engine is off and you only have 12.6V or less. Hard to regulate down from 12.6V to 12V. regulators need more headroom over the regulated voltage than that.

 

[dvandsm64]

Re: how much voltage fluctuation can a TV take.

No its not. An inverter converts DC to AC. You are an electrician?

sorry, bruce, you are right. i wrote it *** backwards. convertor changes dc to ac!