TFT Flatscreens

[Scotland_fan]

Hi,

I am a computer manager, so I am well up on the techie side of things generally. However, I am interested in getting a flatscreen for my caravan and I know that most P.C, Home TV and mobile caravan versions, work on 12v AC - they have a transformer to step down the 240V ac to 12v ac. I also understand that you can get them to work under 12V DC, from the car's cigerette lighter, as the saleman at Earls Court showed me. However, no salesman could understand what I was saying when I wanted to know if it would work under 12v dc off the caravan battery. One salesman said you could [vaguely] and the other said you run it from the car battery with an optional lead. I thought this is rediculous as you cannot leave you ignition on with a lead dangling outside the van, running your car battery flat.

So! Can someone please tell me if it is possible to plug a flatscreen into the 12v socket IN THE CARAVAN!

Thanks to you all,

Toby.

 

[WatsonJohnG]

YES you can but TFT seem more sensitive (mine does) to voltage drop and you can get sound with no picture.I have rewired with heavier cable via a fuse from the van battery to the Tv socket .See my reply earlier in the week to save repetition A problem my friend had with an LG TV was getting the peculiar TV plug and after an exhaustive search (Maplins etc etc) Leisure Power of Warrington were able to supply one.Hope that helps

 

[ProfJohnL]

Hello Toby, Electricaly there is no difference between car and caravan batteries- both produce a nominal 12Vdc, However the voltage does not stay at 12V, under chrging conditions it can rise to 14.5V, and under dischrage can fall to 10V. Most computer grade elctronics prefer a much more stable voltage (typically only 0.1V variation), so the TFT screen may malfunction if run directly from the "12V" power. There are solutions. Maplin Electronics offer some regulated switchmode supplies for running laptops in cars. There may be one which regulats the 12V suitable for your TFT, alternativley, again Maplin and others sell Inverters that convert 12Vdc to 230V ac, and then you use teh TFTs normal plug in power supply.

 

[Bigpow_5039962]

You could be an interuptable power supply unit to keep your voltage stable. . I used to sell computers into industry and eductaion authorities. Where you have a circuit that is being used for welders grinders etc and the odd computer to save the hard drive this is what we used.

 

[Scotland_fan]

Thanks to all those who have responded, however, how do you actually plug either the manufacturers cigarette cable or an inverter to the caravans 12v socket?

Also, is a 12v to 230v inverter really a stablised psu?

Thanks.

 

[WatsonJohnG]

To plug into the van 12V you can buy a short adaptor lead :van-cigar socket or you can cut off the cigar plug and with correct polarity fit a caravan type plug instead. You could fit a cigar socket adjacent to the TV point but the caravan plug is a better fit .You do not need to use an inverter as the Tv supply is 12V so you would be going up to 230V and back to 12V again.It is possible to get a 12V voltage stabiliser (

 

[Jamie_5040651]

I'm struggling to work out what the problem is here. We bought an LG TFT from Argos at the beginning of the season. Pluged it into the normal 3 point 230v socket with the lead and plug supplied and switched it on. No problem. The area in the Scottish Borders doesn't have the best signal strength but we get a much better picture than we did with the old portable.

 

[MikeG2]

You don't sound very techie to me - If your TFT is powered via an ac mains adaptor (most are) which outputs 12v dc, then it will run off the caravan battery. Most good electronic spares shops will sell you the plug for the TV (Maplins are available online) aand the 12v plug can be had from any caravan dealer. Make sure you get the polarity right.

MikeG.

 

[WatsonJohnG]

Our local (Audley Kwik Save) store has Beko 15in TFT TV for

 

[ProfJohnL]

Note for Mike G, please see my previous reply dated 11 Nov, Yes caravans do have sockets marked as 12V but the tend to produce almost anything between 10 to 14.5V depending on the state of charge of the battery, and whether the charger is turned on or not. TFT screens tend to use components from the computer industry, which are very sensitive to voltage, and unless they are supplied with a voltage very close to that stated (e.g. 11.9 to 12.1V) then they may not function correctly. Other respondnats have reported TFT screens not working becuase the voltage was too low, even though other equipment worked normally.

 

[Bill_5039935]

Although not techie minded this may help for those who are bought 7" tft widescreen tv last year been running in caravan all summer on 12volt straight into plug no stabilisers it works on full battery at start of rally or holiday and is still working at end when battery is getting low no change to picture hope this helps you techie minded people.

 

[Daz_5040169]

We use a roadstar 5inch screen with no problems,we chose the small screen size as this has very low power consumption,an important consideration as we very rarely use mains.We have an adaptor that has a 2 pin 12volt plug on one end,and socket that accepts a car cig lighter plug on the other.however i did remove the cig lighter plug and fit a 2 pin plug.The other thing we got was a pair of amplified speakers,the kind designed for a walkman,this improved the sound no end.

So yes run it off the battery but don't forget that the 12volt tv sockets in a caravan are fused at 10amps,so check the consumption of the t.v if you go for a big one,if power is shown in watts work out the amps drawn by dividing watts by volts

H.T.H

 

[Jonno_5040777]

I must come to MikeG's defence here. Our "techie" correspondent has his ac and dc in a twist. If the output from the mains power unit is 12v ac, then it is improbable that it will work off of the caravan battery (although I have experienced "smart" technology which can work off of either - but not in the TV industry). Yes, TFT screens use components which are common to the computer manufacturing industry - in fact most PC monitors nowadays are a actually little more than TV without a tuner. This doesn't mean that they will not work off of the battery. The question was based around the ability for it to work off of the caravan battery, based upon the premise that it would work in the car - notwithstanding the condition of the battery. In my experience, a good quality caravan battery is quite stable - dependant on the load and capacity of course. I tend to use gas as much as I can when away, to keep my capacity up!

 

[Jonno_5040777]

And before you all rush - I am referring to battery voltage with no charger connected. If the charger was connected, you could run the TV off mains couldn't you?

 

[robertd_5041753]

hello i work in the car audio industry,i also work on coaches which we reguarly fit samsung fmt15 tft screen ,which we just remove power supply from input lead and connect to 12 volts and they work perfectly i also have one in my caravan ican tell you where to buy one of these samsung screens from at a sensible price,they can also be used as a computer screen

 

[Willy_5041515]

I can't think what all the fuss is about! The 12V DC input on TV's is obviously meant for use with a car/caravan 12V DC supply, even though this can be anything from 10.5 to 14.5 V. Any competent designer is well aware that input voltages can vary over a reasonable band. For example 230 V AC can legally be 219.5V to 240.5V and in Europe varies much more than this. Any competent TV designer allows for this. I think you are worrying unecessarily.