Guest Frank Wilkinson Posted November 21, 2006 Share Posted November 21, 2006 I posted this question in another thread a few hours ago and despite plenty of traffic on the site no one's answered it yet so I thought I'd make it a separate topic.I admit to know nothing about electricity and I'm curious to know if a 12v digibox consumes less power from your leisure battery than a 240v one being used with an inverter.I have a 240v digibox and may consider an inverter but if it's going to use more power I'll invest in a 12v version.Thanks in advance to any of the experts here who can help. Link to comment Share on other sites More sharing options...
Bill Ord Posted November 21, 2006 Share Posted November 21, 2006 I'm not claiming to be an expert but watts are watts at what ever voltage. My 12 volt box has marked on the underside 1.25 amp so it's consumption so to speak is 15 watts. Your 230 volt box will have the current consumption on it somewhere so have a look it will probably be underneath. The only problem with running from an invertor is the invertor will be about 90% efficient so add 10% to the wattage. If you intend to run your TV from an invertor you may get lines appearing on the screen unless you use a sine wave invertor which are cconsiderably more expensive. Link to comment Share on other sites More sharing options...
colin Posted November 21, 2006 Share Posted November 21, 2006 Using a 240v box on 12v, you will be converting 12v dc to 240v ac, box will then convert this back to dc, so there is a double loss. How much less will you use? this would depend on invertor and design of box, at a guess you may on a good day use 80% if using direct 12v. As it happens I have a 240v and 12v box of same design and an invertor, so if I get the time I'll have to check differance in current draw, but don't hold your breath waiting for me to do it. Link to comment Share on other sites More sharing options...
Clive Posted November 21, 2006 Share Posted November 21, 2006 Using the 12 volt direct must take slightly less power than using a 240 volt one and an inverter. BUT if you decide to use the 12 volts direct you will not have the regulation, spike protection and galvanic isolation provided by the 240/12 volt digibox power supply. I don,t have any satellite equipment whatseover myself but the same arguement exists for 12 volt LCD television sets and some Laptops which we do have. I believe its safer to accept the small inverter loss and retain the manufacturers mains power supply which includes all the required filters. There are some very small inverters sold specifically for this type of duty but if you have other reasons to make use of an inverter then why not have a more usefull sized one? Are you that close on battery capacity for it to be of concern? C. Link to comment Share on other sites More sharing options...
Dave Newell Posted November 21, 2006 Share Posted November 21, 2006 Clive and myself have had this debate several times in the past and I think I'm safe in saying we now agree to disagree. My preference would be to use native 12 Volt equipment with a regulator or in the case of a laptop a 12 Volt to whatever Voltage is required converter. D. Link to comment Share on other sites More sharing options...
Guest Frank Wilkinson Posted November 21, 2006 Share Posted November 21, 2006 Thanks everyone. I'm not sure why I'd need some kind of protection as with a 12v digibox I'd be running it off a 12v leisure battery so I'm not sure what kind of spikes or surges it could suffer.From the opinions offered I'm thinking that I'll be better with 12v equipment rather than an inverter.I would like to think that if we camp wild for a night we can enjoy a few hours of TV if there's nothing else to do. My new MH has a built in 12v TV and Free to Air Box but of course that's no use in Europe so to complete the package I was thinking about buying a 12v Sky digibox and now I think I'm convinced.Thanks again for all your help and opinions. I really do appreciate it. Link to comment Share on other sites More sharing options...
mover Posted November 22, 2006 Share Posted November 22, 2006 You could need 12 v protection for your 12v appliances as a fully charged 12v battery wiil be at about 14-5volts BANg!!! *-) *-) Link to comment Share on other sites More sharing options...
Frankkia Posted November 22, 2006 Share Posted November 22, 2006 Totally agree! We had a 12v LCD which had no end of problems with over voltage so we put an Amperor connector in between - problem solved. We now also have a Pace Javelin sky 12v box which is rated at 12v + or - 5% ie max 12.6v so we have fitted a regulated 12v adaptor to that too. This adaptor is the one Dave Newell suggested to us and is avalable from Maplins http://www.maplin.co.uk/Module.aspx?ModuleNo=48574&doy=12m10&ForceUpdate=Y We regularly have a voltage of 14.6v as we use 2 x 120w solar panels to feed our tv habit so any 12v equipment is pushed to it's limit Link to comment Share on other sites More sharing options...
spartan3956 Posted November 22, 2006 Share Posted November 22, 2006 Bernie Can you tell me how many amps/watts the sky box runs on Im using a 230v sky box at the moment Pete Link to comment Share on other sites More sharing options...
Guest Frank Wilkinson Posted November 22, 2006 Share Posted November 22, 2006 I've learned something else! When I have my new dish and 12v digibox fitted I'll check to make sure that my motor home has some kind of surge resistor. It may well have as it comes complete with a 12v TV/DVD and a Freeview box. If it doesn't have one I'll make sure that the company in question fits one.An acquaintance in the business told me today that I shouldn't buy a 12v Sky box. he reckons that none have been produced for three years and that there may well be problems with servicing eventually.He also said that it is rumoured 'in the trade' that channels 4 and 5 will not be encrypted from next Spring. I've now decided to buy a Free to Air digibox and hope that this happens. These boxes are half the price of 12v Sky boxes and as I'm not a Sky subscriber anyway I'll still get all the programmes that I need.Thanks everyone for the inverter, surge advice. Link to comment Share on other sites More sharing options...
Dave Newell Posted November 23, 2006 Share Posted November 23, 2006 Hi Frank, its not actually a surge protector that you need its a voltage regulator. Most 12 Volt equipment in this area, TVs, digiboxes, etc are actually designeds to be powered from a 240Volt PSU that gives a regulated supply. Your 12 Volt circuits in your 'van are unregulated, that is to say full battery voltage is present and this can be up to 14 Volts if you've just finished a drive, are on hookup or using a solar panel. As has already been said the Pace 12 Volt digibox is rated for 12Volts +/- 5% and if you feed it a raw 14 Volts it will die. Some equipment does have built in voltage regulation but not always so a regulator, while not always vital, is probably a good idea. D. Link to comment Share on other sites More sharing options...
Guest Frank Wilkinson Posted November 23, 2006 Share Posted November 23, 2006 Thanks for that and I understand exactly what you are saying but, as I said, my new MH comes complete with a manufacturer-fitted 12v LCD TV/DVD player and a 12v Freeview box. Surely they ought to be aware of the threat that you pose and one would assume that in this case, my MH has some kind of protection already fitted? If it didn't they could be facing quite a few warranty claims.Does anyone else have a MH with a 12v TV system pre-installed by the maker and if so, does it have some kind of protection of the type that I now accept I need? Link to comment Share on other sites More sharing options...
Basil Posted November 23, 2006 Share Posted November 23, 2006 Frank, Don't forget Maplins are doing the 12v or 240v 'Free to Air' in a suitcase setup, haven't checked but it was £69.99 last time I looked and is a good value setup for a complete system, you just need the TV. Mine is very good when it is working my problem is I am no good at setting it up, but I would have that problem with any manual one, so just can't be bothered! :'( :'( :'( Bas Link to comment Share on other sites More sharing options...
Frankkia Posted November 23, 2006 Share Posted November 23, 2006 [QUOTE]spartan3956 - 2006-11-22 10:37 PM Bernie Can you tell me how many amps/watts the sky box runs on Im using a 230v sky box at the moment Pete[/QUOTE] Hi Pete The 12v Pace is rated at 15w max i.e. 1.25A max which is another good reason to use it as it is very low compared to a normal 230v box. As to the other posts on this subject - 1) It is quite correct that the Javelin is out of production but there are still a number available both at the full price of about £199 and the refurb price of about £159. 2) As far as I am aware ch4 and 5 both have contracts with Sky to 2008 and after that date they are considering going FTA. Link to comment Share on other sites More sharing options...
Frankkia Posted November 23, 2006 Share Posted November 23, 2006 [QUOTE]Frank Wilkinson - 2006-11-23 8:16 AM Thanks for that and I understand exactly what you are saying but, as I said, my new MH comes complete with a manufacturer-fitted 12v LCD TV/DVD player and a 12v Freeview box. Surely they ought to be aware of the threat that you pose and one would assume that in this case, my MH has some kind of protection already fitted? If it didn't they could be facing quite a few warranty claims.Does anyone else have a MH with a 12v TV system pre-installed by the maker and if so, does it have some kind of protection of the type that I now accept I need?[/QUOTE] Having seen some of the wiring going into some "modern" motorhomes I would be very surprised if they had put any kind of over voltage protection in. Link to comment Share on other sites More sharing options...
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