# how to power tv?



## redbarron (Feb 6, 2011)

Hi

We have just bought our first motorhome, with which we are thrilled. It is fitted with a Grundig Elegance tv but I am puzzled as to why the 12v tv AC adapter is plugged into an inverter? Surely I could just wire the tv into the 12v electrics of the motorhome? Am I missing something?

You may gather from this that I am not technically minded and you would be correct!

Any advice would be very much appreciated.

Richard


----------



## Mike48 (May 1, 2005)

redbarron said:


> Hi
> 
> We have just bought our first motorhome, with which we are thrilled. It is fitted with a Grundig Elegance tv but I am puzzled as to why the 12v tv AC adapter is plugged into an inverter? Surely I could just wire the tv into the 12v electrics of the motorhome? Am I missing something?
> 
> ...


If your TV was plugged direct into the the 12v system then there is a possibility the TV will blow as it is not designed to operate in this way. Voltage in a motorhome is unstable and your particular TV might not be able to cope with a peaked voltage of up to 14.4volts. Some people do plug domestic TVs direct into the 12volt system but why bother if you already have an inverter installed?


----------



## trevorf (May 16, 2005)

If your TV has a 12V dc input then you can wire it direct to the van 12V system.
If you do a search on the subject on this forum you will find many people only recommend doing so using a 12V stabilizer. 

Personally I have been using a 12V sky satellite box direct to my vans 12V system for many years without any problems and do not think a stabilizer makes much difference.



Trevor


----------



## erneboy (Feb 8, 2007)

Yep, using an inverter to give 230/240 to step down again is very inefficient. I have always wired direct and without a stabilizer but if you want to be sure using would be best, Alan.


----------



## UncleNorm (May 1, 2005)

Our MHF friend, Shane Snell of Snellyvision, has set up our entire system to run off 12v only... the automatic satellite dome, the decoder box and the TV. The TV runs through a stabilizer to protect it.

As an aside, when we actually used our static motorhome in France, after breakdown, it was great to switch on the three items, with the dome tuning in so quickly, to see the Tour de France LIVE. The system Shane fitted, back in April, worked so well.  Well impressed. :wink:


----------



## Zebedee (Oct 3, 2007)

Do a bit of research about your TV Richard.

Many modern ones have a stabiliser (or something very similar) built in already. Our Alden one has, and it has been permanently wired in (very much like Uncle's system) for 18 months now, with no problem at all.

I think our telly will run on 12 - 24 volts (though I may be wrong) in which case there is nothing to worry about.

I hate having to faff around when on holiday, so I have three switches to use when we want the telly on.

One for the auto satellite finder on the dish, one for the decoder box, and a third for the telly. I could have wired them all into one switch, but if we are watching a video or looking at Mrs Zeb's photo's we don't want the dish or decoder switched on.

A 12 volt stabiliser is only about £15, but it's bulky and gets in the way, so if you can do without it you will have a much neater job.

Hope this helps

Dave


----------



## redbarron (Feb 6, 2011)

Many thanks to all of you. I'll try a bit of research on the tv first, but I'm inclined to buy a stabiliser and run it that way.

Richard


----------



## Wizzo (Dec 3, 2007)

If it helps I ran my last tv directly from 12v supply having cut the wire after the 12v converter box. It would never run off my cheap inverter anyway. I have used it successfully for the last 3 years and have just replaced it with a larger dedicated 12v LED/LCD.

The old one would run at any voltage you cared to pump in (from 10.8 to 14v) without problem.

Just make sure that you identify which are the live and neutral wires though.

JohnW


----------



## BwB (Dec 5, 2009)

And before you do any of those suggestions (which are all valid) just check to make sure that the 12v coming out of the TV's power supply is DC. Some are, occasionally, AC output.

It will say on the Power Supply what it is.

Some 'vans have a habitation 12vdc supply which is already stabilised which might be worth checking before you install another one.

<<I'm no electric expert. The information above is from personal (sometimes expensive) experience>>


----------



## redbarron (Feb 6, 2011)

Just as an update I visited our local Maplin store with a copy of the tv manual and the mains transformer, expecting some expert advice. Having explained the situation I was told 'you need one of these mate' (pointing to a rack of inverters) - I repeated that I already had one and was trying to eliminate it if possible. I was then told that I was best to stick with the inverter as I was only losing 5-10% efficiency. They did not sell a lead/stabiliser with the 5amp capacity, the maximum being 3amps. However, I will persevere!


----------



## Zebedee (Oct 3, 2007)

redbarron said:


> Just as an update I visited our local Maplin store with a copy of the tv manual and the mains transformer, expecting some expert advice. Having explained the situation I was told 'you need one of these mate' (pointing to a rack of inverters) - I repeated that I already had one and was trying to eliminate it if possible. I was then told that I was best to stick with the inverter as I was only losing 5-10% efficiency. They did not sell a lead/stabiliser with the 5amp capacity, the maximum being 3amps. However, I will persevere!


Ignore the plonker at Maplins, and rely on the first hand experience of a lot of very clever motorhomers. :roll:

The advice you have been given on this thread is sound.

If you really need a voltage stabiliser Snelly sells them, and he is a real "professional" expert because that's his livelihood. Why not give him a call - he's a very nice bloke and will help you all he can. :wink:

He's a member of MHF too!

http://www.snellyvision.co.uk/store/index.php

Dave


----------



## redbarron (Feb 6, 2011)

Thanks Dave, you are right of course! I went to a local supplier here in York (like Alladdins cave) and the guy sold me the connectors and wire and I made up the lead myself - what's more, it works! Turns out the guy in the shop has a motorhome and knew all about it. He said I don't need a stabiliser but to simply avoid starting the engine when the tv is switched on.

Now all I have to do is work out how my wife can dry her hair when we're not hooked up!


----------



## Zebedee (Oct 3, 2007)

redbarron said:


> Now all I have to do is work out how my wife can dry her hair when we're not hooked up!


Glad to help you get sorted. 

Mrs Zeb has a fantastic gadget for drying her hair. It's called a towel. :wink: :lol: :lol: :lol:

Dave


----------



## Jean-Luc (Jul 21, 2005)

THIS is the piece of kit you want. 
I have used one for the past six years without problem.


----------



## spykal (May 9, 2005)

redbarron said:


> He said I don't need a stabiliser but to simply avoid starting the engine when the tv is switched on.


Hi

The reasoning behind that is that when the engine is running the voltage at the 12v battery will rise ..maybe as high as 14v+.

To have completed his advice he should have also added that you should use the normal TV power supply when you are on a 240v hook up at a campsite as when hooked up the battery will be charging and the voltage will be well above a nominal 12v.

Both of these scenarios can be avoided by using a voltage stabiliser in the TV lead that will maintain the correct 12v to the TV under all circumstances.

Mike


----------

