Inverter advice please!

Freestyle

Freestyle

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I am trying to get a flat screen tv to work in the van but although it works on a step down transformer from the mains as it is designed to it will not work direct from a 12v battery.
I am wondering if an inverter would be the answer s this would convert the 12v to 240v.Does this sound like the solution or am I missing something here
I have seen a 150w inverter. Would this do the job?
On the convertor that comes with the set it says that the output is 12v at 5.0A. I know nothing about this sort of thing. (I still think that computers are worked by witchcraft)!
Would be really pleased to get some help with this! Thanks :)
 
Freestyle said:
I am trying to get a flat screen tv to work in the van but although it works on a step down transformer from the mains as it is designed to it will not work direct from a 12v battery.
I am wondering if an inverter would be the answer s this would convert the 12v to 240v.Does this sound like the solution or am I missing something here
I have seen a 150w inverter. Would this do the job?
On the convertor that comes with the set it says that the output is 12v at 5.0A. I know nothing about this sort of thing. (I still think that computers are worked by witchcraft)!
Would be really pleased to get some help with this! Thanks :)
Click to expand...

I am no expert on this subject, but yes an inverter is the answer, however I do not know what size you would need!. I suspect that the 150w is too small!:eek: and better to get a larger one as you could then power other items as required:cool:
The flat screen tv will not work efficiently direct from your 12v batteries because the voltage is not stable enough and fluctuates:eek:
I am sure that someone will add more specific details about this, but I am also sure that my answer is correct;)
Hope this helps in the meantime

edit,
Basically, you need to check the specification of the tv to see what power it uses (watts & amps) and the inverter must be able to supply that amount plus a little bit more, probably 10% but I would think that 25% would be a better safety margin!
I am sure that someone will elaborate
 
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Converter ?

Most of this digital wonders operate on 18V. (my laptop does) Don't ask me why :eek: Just check out what the input V is needed.
If you use a converter 12V>240V (you loose power) then you have to tranfso it back 240V>18V (second loose of power). Futher more this is 'flattened' direct voltage. You have a double amount of 'fluctuations' and instability. There are very cheap converters on the market 12V>18V; no risc of variations or fluctuations. This was an advice of my retailer; and it works.
Also why buy a separate flatscreen ? For the same price you have a laptop
with all computer-extra's with it, and all are able to give you TV. OK the screen is slightly smaller than a sepatate flatscreen, but I think you want
'home-movie' in your MH.:confused:
 
Freestyle said:
I am trying to get a flat screen tv to work in the van but although it works on a step down transformer from the mains as it is designed to it will not work direct from a 12v battery.
I am wondering if an inverter would be the answer s this would convert the 12v to 240v.Does this sound like the solution or am I missing something here
I have seen a 150w inverter. Would this do the job?
On the convertor that comes with the set it says that the output is 12v at 5.0A. I know nothing about this sort of thing. (I still think that computers are worked by witchcraft)!
Would be really pleased to get some help with this! Thanks :)
Click to expand...

If it is solely to run the TV would a voltage regulator such as this: http://www.action-replay.co.uk/Computing/12v12vDC_power_adapter.shtml Be a better bet than an inverter, and about half the price
 
hi

Hi G, I run my flat 14 inch TV from the batteries, also with the free view box and so on, we have a line free pic all the time. The thing to bear in mind with inverters is the wave sigh that the inverter uses, if its a sq ware then there will be lines on the pic, I picked up a 3000 watt inverter off e-bay and used it once, Also remember that inverters use power, so if you are planning to run a tv from one, then you will need to take account that more power will be pulled from the batteries, unless you are planning to use said tv on a site.
before buying your inverter, have a look at the price of 12v tv,s they are coming down in price all the time.
terry
 
Kell has got it in one. If you are going to run it direct from a battery then you need a voltage regulator to smooth out the lumps and bumps of the supply
 
Sounds good

I never thought of that, but it sounds good and I would expect that the battery would last longer:cool:
 
Anything to avoid putting current through an inverter has to be good. They are not very power efficient.
 
My TV works fine, so I think your problem is voltage drop, not all 12v sockets like to supply 5amp. Plug the TV in and try and measure the supply at the socket... and as stated MANY times on this subject do NOT try this with the engine running! As your 12v TV find itself getting 14.2V!!
Do persist as like others have said it is very inefficient to chop & step up from 12v DC to 240v AC and then to step it back down to 12v again.
 
Hi there

Unless it is a very large flatscreen a 150w invertor will be more than enough (it will even power a DVD player too...)

Personally I would avoid a voltage regulator, it may seem like a sensible solution staying at 12v, But they are extremely inefficient, unlike modern invertors which are better than 95% efficient, I cannot find the figures right now, but I tested a TV with a borrowed voltage regulator and also powered the same TV via invertor, surprisingly the invertor used less power. I only checked after someone else found the same thing.
 
GeorgeTelford said:
Hi there

Unless it is a very large flatscreen a 150w invertor will be more than enough (it will even power a DVD player too...)

Personally I would avoid a voltage regulator, it may seem like a sensible solution staying at 12v, But they are extremely inefficient, unlike modern invertors which are better than 95% efficient, I cannot find the figures right now, but I tested a TV with a borrowed voltage regulator and also powered the same TV via invertor, surprisingly the invertor used less power. I only checked after someone else found the same thing.
Click to expand...
so it woulod be more efficient for me to run my 15" tv off an inverter (which when my air con is installed i will already have) than it would be to go out and get a voltage regulator?
 
iv'e got a wee 150w, i dont think i've even used it as i am paranoid about flattining the battery,and i would'nt use a telly or anythin on it the most a battery charger or a razor,the wee man sometime's put's his gameboy on it..
 
Hi Walkers

Yes I would say so, when "we" posted about this before no-one came up with any credible evidence to show a regulator was more efficient.

Cant for the life of me think who the other person was who tested this out...
 
GeorgeTelford said:
Hi Walkers

Yes I would say so, when "we" posted about this before no-one came up with any credible evidence to show a regulator was more efficient.

Cant for the life of me think who the other person was who tested this out...
Click to expand...
thankyou i will take your advice on this, as i know you have put the research in. regards tony:)
 
GeorgeTelford said:
Hi Walkers

Yes I would say so, when "we" posted about this before no-one came up with any credible evidence to show a regulator was more efficient.

Cant for the life of me think who the other person was who tested this out...
Click to expand...

Chas, Sterling, I believe
 
Hi Baloo

I have chatted to charles sterling, but it was a selfbuilder who set me off looking at this, at that time I was reccomending a regulator as its the "obvious" answer (it appears sensible to assume that converting to 240 volt only to then reconvert down to 12 volt is going to use more power than simply regulating 12v, however the reality didnt agree)

The other suprise result was that straight 12v TV's used more amps when run on 12v than running the same set via invertor !!
 
OP said - "On the convertor that comes with the set it says that the output is 12v at 5.0A."

This means the TV draws 60Watts.
If you are not the adventurous type then get a 150W SINEWAVE inverter and be done with it. That way you can use all your other little mains chargers for phone, cordless drill and the like at the same time if you use a powerboard.


If you are a little more adventurous then you can see that the power supply supplied with your TV puts out 12V DC which is the same as the battery voltage so you COULD supply the TV straight from the battery. Many people do it and have no problems at all but there are reports of some TVs that fail - supposedly because the battery voltage can get up to 14.4V when you are hooked up to mains supply and the charger is operating. Whether the electronics are really so poorly designed as to fail at such a relatively small overvoltage is a matter of debate, but it does give the seller an excuse to void the warranty.

For peace of mind buy a quality pure sinewave inverter and forget about minor problems of losing a bit of power because of inefficiency in the inverter. Operating at half power level they are at least 80% efficient and if that amount of loss is a major worry then better to turn the TV off and go to bed.
Only requirement is to turn the inverter off completely when not using it because they do draw some power on standby as well.
-------------------------------
A couple of posts have mentioned lumps and bumps on the voltage supplied from the battery. Where do these lumps and bumps come from???
 
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