Stable 240V output from inverter for Satellite box

[Henrym]

We have a satellite dish and 12V satellite receiver which work well.
However, when we want to watch encrypted programmes, we need to use our ‘Sky plus HD’ box, which requires a 240V input.
Our old Sky box worked well powered by one of two inverters. One is high power (300W), the other small (50W). However, the new box seems to be more sensitive to the input voltage (I assume) as it works erratically, and when I checked with a DVM both of the inverters had an output voltage (little or no current flowing) well over 240V - over 300V!!! I guess it is tripping out when the voltage gets too high. The work-round has been to use a generator which provides the required 240V +/- much less than the inverters. But this is far from ideal. Don't like disturbing the countryside when we have found a good 'wild' place!

I have seen various voltage protective devices but the problem can be that they cut the connection if the voltage exceeds a certain value. What I require is a device that will limit the voltage, constraining the output rather than disconnecting. If it cuts, the box goes off and takes time to reboot. As I see it, it needs a well-regulated power supply, like the ones used by laptop computers that provide a stable output regardless of input voltage from 100-250V. Would a surge/spike protector sold by computer shops do the job?

Or can I break into the Sky+HD box, by-pass the power supply board and connect 12V directly to the main electronics?

 

[wildebus]

We have a satellite dish and 12V satellite receiver which work well.
However, when we want to watch encrypted programmes, we need to use our ‘Sky plus HD’ box, which requires a 240V input.
Our old Sky box worked well powered by one of two inverters. One is high power (300W), the other small (50W). However, the new box seems to be more sensitive to the input voltage (I assume) as it works erratically, and when I checked with a DVM both of the inverters had an output voltage (little or no current flowing) well over 240V - over 300V!!! I guess it is tripping out when the voltage gets too high. The work-round has been to use a generator which provides the required 240V +/- much less than the inverters. But this is far from ideal. Don't like disturbing the countryside when we have found a good 'wild' place!

I have seen various voltage protective devices but the problem can be that they cut the connection if the voltage exceeds a certain value. What I require is a device that will limit the voltage, constraining the output rather than disconnecting. If it cuts, the box goes off and takes time to reboot. As I see it, it needs a well-regulated power supply, like the ones used by laptop computers that provide a stable output regardless of input voltage from 100-250V. Would a surge/spike protector sold by computer shops do the job?

Or can I break into the Sky+HD box, by-pass the power supply board and connect 12V directly to the main electronics?

I would be surprised if both inverters were outputing such a high value. a genuine 300+ V would probably damage devices plugged into them. I would be suspicous of the DVM.
Are the Inverters Pure Sine Wave or Modified Sine Wave? Also try the DVM on a home socket in the house and see what that reads as a control.
This is very unlikely to be over 250V. Nominally UK mains is 230V +/- 10%
I've checked the outout on the Inverters I have and they are all within an acceptable range

 

[Obanboy666]

Cannot help you regarding inverter output voltage, complete numpty with most things electrical. I’m just curious as to why you use a sky plus hd box in your motorhome.
Unless you are wanting the record and pause / rewind facilities just use a sky multi room box, that’s what I am using at present.
It is physically smaller and uses under 1/2 the amps the sky plus box uses, in the depths of winter when wilding that can make your batteries last longer. I had a spare multi room box but they can be found on fleabay for next to nought.

 

[Deleted member 3011]

Buy a pure sinewave inverter.

Some meters measure the peak value of the waveform and multiply it by a factor to give an RMS value. Works perfectly well for a pure sine wave because that ratio is fixed.
However for a modified square wave inverter the waveform has a much higher peak voltage to RMS ratio so simple meters will/may read high.
A good meter will actually calculate the correct value over the whole cycle.

Even then, many electronic devices just won't work well unless they are being supplied by true sinewave supply

 

[GregorM171]

Yes have to agree with the last comments!
To run sensitive electrical equipment like your Sky box or laptops, you most definitely require a pure sine wave inverter. If not, in time you will damage the components and in the short term will cause interference with the device e.g. humming with audio equipment.

Gregor.

 

[chas142]

Like the others I think you need to check your DVM in a household socket to start with, make sure that is reading correctly. Once you have done that I would check the voltages from both invertors and your generator, is your generator a 240v inverter type?


I have 2 inverters one is modified sine wave and the other is pure sine wave. I have tested them with a Lidl / Aldi DVM and a I have a Digital Storage Oscilloscope MT8206 Intelligent Multimeter Diode Tester. The modified sine wave inverter read 180v, (from memory), on both meters and is square wave. The pure sine wave inverter reads 220/230v and show as multi stepped sine wave, it almost as good as from the mains but not quite the same. You would need a better scope to get a clearer picture.


Also try you system on mains, if it's all right there, and I suspect it will be as it works on your generator it may be that your inverters a square wave, there is about 4 or 5 different types of wave forms put out by different inverters, not all electrical items will work on them as they require a pure sine wave or as near to it as you can get. Of course the manufacturers tell you its pure sine wave, or modified sine wave and it just basic square wave.

Your old sky box might have been ok and you new one isn't.

 

[oppy]

Surely wild camping is not about fretting whether satellite tv is available or not, it's more about enjoying where you are . We had a system that we got when we were tuggers, so much of a faff, so we didn't use it, when we joined this group I offered it but no responce so it got chucked, which led me to believe that wild campers, like us, are content to maybe watch telly if it's available, otherwise just enjoy each others company and do stuff like we used to do before technology kicked in.

 

[chas142]

Surely wild camping is not about fretting whether satellite tv is available or not, it's more about enjoying where you are . We had a system that we got when we were tuggers, so much of a faff, so we didn't use it, when we joined this group I offered it but no responce so it got chucked, which led me to believe that wild campers, like us, are content to maybe watch telly if it's available, otherwise just enjoy each others company and do stuff like we used to do before technology kicked in.

I am only trying to answer the technical side, I have a tv and a satellite dish but never fitted it / used it in 15 years.

 

[Henrym]

I would be surprised if both inverters were outputing such a high value. a genuine 300+ V would probably damage devices plugged into them. I would be suspicous of the DVM.
Are the Inverters Pure Sine Wave or Modified Sine Wave? Also try the DVM on a home socket in the house and see what that reads as a control.
This is very unlikely to be over 250V. Nominally UK mains is 230V +/- 10%
I've checked the outout on the Inverters I have and they are all within an acceptable range

The big one is a solidly built older model, the smaller one Ring brand, so probably neither Pure Sine Wave. The DVM shows a fluctuating 240-250V. A bit high, but acceptable for guidance. What well-behaved inverters do you have? Presumably pure sine wave; do they have over/under voltage protection? I guess I need a quality inverter with these features, but an output power of 50-100W so that the no-load current is small - not 3000W (for example).

 

[Henrym]

Cannot help you regarding inverter output voltage, complete numpty with most things electrical. I’m just curious as to why you use a sky plus hd box in your motorhome.
Unless you are wanting the record and pause / rewind facilities just use a sky multi room box, that’s what I am using at present.
It is physically smaller and uses under 1/2 the amps the sky plus box uses, in the depths of winter when wilding that can make your batteries last longer. I had a spare multi room box but they can be found on fleabay for next to nought.

In the past, I had various items that required the inverter; not now, even the computer has its solid state 19V output device that plugs into the 12V supply. Now it's just the Sky+HD box, when my wife wants to watch football when we are on the road (I have to keep her happy when I drag her out). For other programmes, the 12V Icecrypt receiver (supplied and set up by Robert Jackson) draws minimal current, and gives us the option of getting certain programmes from Hispersat. Good if there is a hill to the SE, and it also covers most of Western Europe. But, the Sky card will only unlock sports programmes (for example) when it is in the Sky+HD box - it does not work in the Icecrypt and not now (after reassignment) in the old Sky box. The evil empire is afraid of n're-do-wells infringing their monopoly! We were forced to upgrade because one footy channel went from SD/HD to HD only!

 

[Henrym]

I have 2 inverters one is modified sine wave and the other is pure sine wave.

Also try you system on mains, if it's all right there, and I suspect it will be as it works on your generator it may be that your inverters a square wave, there is about 4 or 5 different types of wave forms put out by different inverters, not all electrical items will work on them as they require a pure sine wave or as near to it as you can get. Of course the manufacturers tell you its pure sine wave, or modified sine wave and it just basic square wave.

What is your 'good' inverter?
The Sky+HD box works in the house; I have to disconnect it to take it to the motorhome (quicker as I have co-ax connectors just down the wire).

 

[chas142]

In the past, I had various items that required the inverter; not now, even the computer has its solid state 19V output device that plugs into the 12V supply. Now it's just the Sky+HD box, when my wife wants to watch football when we are on the road (I have to keep her happy when I drag her out). For other programmes, the 12V Icecrypt receiver (supplied and set up by Robert Jackson) draws minimal current, and gives us the option of getting certain programmes from Hispersat. Good if there is a hill to the SE, and it also covers most of Western Europe. But, the Sky card will only unlock sports programmes (for example) when it is in the Sky+HD box - it does not work in the Icecrypt and not now (after reassignment) in the old Sky box. The evil empire is afraid of n're-do-wells infringing their monopoly! We were forced to upgrade because one footy channel went from SD/HD to HD only!

My pure sine wave is 3000/6000 watt, I got carried away in an ebay auction, cost me about £85, new. If you look to buy you must check out all the details, only buy if it has pure sine wave written on the inverter, when looking you will see the tricks they play in the listings, but I don't think they know what they are selling themselves. I will see if I sill have the lists of the ones I checked out later, if I have I will see if I can list some, its a minefield, which is why I purchased a scope / meter.

 

[Obanboy666]

In the past, I had various items that required the inverter; not now, even the computer has its solid state 19V output device that plugs into the 12V supply. Now it's just the Sky+HD box, when my wife wants to watch football when we are on the road (I have to keep her happy when I drag her out). For other programmes, the 12V Icecrypt receiver (supplied and set up by Robert Jackson) draws minimal current, and gives us the option of getting certain programmes from Hispersat. Good if there is a hill to the SE, and it also covers most of Western Europe. But, the Sky card will only unlock sports programmes (for example) when it is in the Sky+HD box - it does not work in the Icecrypt and not now (after reassignment) in the old Sky box. The evil empire is afraid of n're-do-wells infringing their monopoly! We were forced to upgrade because one footy channel went from SD/HD to HD only!

I take the sky multi room box with me to watch the football and cricket and just go online and reassign the card to the multi room box. When I come home I just put the card back into my Sky + HD box and when I go to a sports channel I just select pair card to box and job done. So your card only works in the box in your house ?

 

[Obanboy666]

Surely wild camping is not about fretting whether satellite tv is available or not, it's more about enjoying where you are . We had a system that we got when we were tuggers, so much of a faff, so we didn't use it, when we joined this group I offered it but no responce so it got chucked, which led me to believe that wild campers, like us, are content to maybe watch telly if it's available, otherwise just enjoy each others company and do stuff like we used to do before technology kicked in.

Being a widower I travel alone and get out as much as possible usually every week or so, it’s not much fun at home looking at the same 4 walls day in day out and the conversation with the dog tends to be one sided. I treat my motorhome as my second home and want everything in it I have at home. Being an avid sports fan I like to watch football and cricket, hence have a satellite system and take the sky box with me.
It’s automatic and takes 2 minutes to setup, no faffing about finding satellites just press one button and job done.
So that’s the reason I have a tv and satellite system, but everyone to their own. Some like me like tv others hate it.

 

[Mr B]

I have a Sky HD box in mine running from a good quality modified sine wave inverter without any issues for many years.

1. You do not need an expensive pure sine wave inverter to run a sky box, which only takes 30w max. Output voltage must be around 230v otherwise internal ky box PSU with thermal out. Many cheap inverters have poor set up and can be around 260v at low load but 230v at nominal load.

2. The Sky HD box will happily run from a good quality (not cheapey Chinac knock off) inverter without issue as it has its own power supply regulation board inside.

3. You cannot hack the Sky HD box and feed it on 12v inside as the PSU outputs differing voltages for parts of the board 3.3v, +5v , 0v, -5v and 12v from memory.

It is highly liklely that your inverter is the source of problem but any decent 300 to 600w modified sine wave inveter will run your Sk HD box without issue

 

[chas142]

In the past, I had various items that required the inverter; not now, even the computer has its solid state 19V output device that plugs into the 12V supply. Now it's just the Sky+HD box, when my wife wants to watch football when we are on the road (I have to keep her happy when I drag her out). For other programmes, the 12V Icecrypt receiver (supplied and set up by Robert Jackson) draws minimal current, and gives us the option of getting certain programmes from Hispersat. Good if there is a hill to the SE, and it also covers most of Western Europe. But, the Sky card will only unlock sports programmes (for example) when it is in the Sky+HD box - it does not work in the Icecrypt and not now (after reassignment) in the old Sky box. The evil empire is afraid of n're-do-wells infringing their monopoly! We were forced to upgrade because one footy channel went from SD/HD to HD only!

You could take her down the pub to watch it I suppose, assuming its being shown. It wouldn't worry me as I don't follow it at all.:goodluck:

 

[chas142]

I have a Sky HD box in mine running from a good quality modified sine wave inverter without any issues for many years.

1. You do not need an expensive pure sine wave inverter to run a sky box, which only takes 30w max. Output voltage must be around 230v otherwise internal ky box PSU with thermal out. Many cheap inverters have poor set up and can be around 260v at low load but 230v at nominal load.

2. The Sky HD box will happily run from a good quality (not cheapey Chinac knock off) inverter without issue as it has its own power supply regulation board inside.

3. You cannot hack the Sky HD box and feed it on 12v inside as the PSU outputs differing voltages for parts of the board 3.3v, +5v , 0v, -5v and 12v from memory.

It is highly liklely that your inverter is the source of problem but any decent 300 to 600w modified sine wave inveter will run your Sk HD box without issue

I think you mean pure sine wave in number 3, not modified.:wave:

 

[wildebus]

The big one is a solidly built older model, the smaller one Ring brand, so probably neither Pure Sine Wave. The DVM shows a fluctuating 240-250V. A bit high, but acceptable for guidance. What well-behaved inverters do you have? Presumably pure sine wave; do they have over/under voltage protection? I guess I need a quality inverter with these features, but an output power of 50-100W so that the no-load current is small - not 3000W (for example).

My inverters are Pure Sine Wave (PSW) yes (Victron brand), and chosen due to the equipment I wanted to use with them.
A genuine PSW will be notably more expensive than a modified sine wave inverter due to the components that are required. The bigger the inverter capacity the bigger the price difference of course. But when it comes to the smallest inverters, the extra cost of buying a Pure Sine Wave inverter has much less impact as neither are massively priced.
I am a bit of a Victron fan as I have never bought anything from them which has not worked well. I have checked the output of the Victron Inverters I have and the wave form is a perfect sinewave. This is not that common even with PSW inverters unless you get the best quality ones.
The cheapest Victron PSW inverter is a 150W Inverter and can be bought for under £70. Admittedly this is a fair bit more that a basic MSW inverter (I bought one from Amazon last week - £22 for a 500W one. Bought solely on price for a specific project where quality didn't matter). So three times the price but .... in real terms, under £50 more for a far far better product.

Now does the no-load current matter? if you switch it on specifically when you want to use the sky box and off again afterwards, not really, but it is true to say that the smaller the inverter wattage is, the more efficient it will typically be running low power devices such as a Sky box, so Hairydogs point (quoted below) I would go along with. It can be tempting to buy a much more powerful inverter then is really needed 'just in case' for the future, but it really is counter-productive in terms of power usage.

If you only want to power a 30 watt load, buy a 100 watt inverter, or smaller. That way the inverter will be in its comfort zone.

As an aside, why do people question WHY someone wants to run a Sky Box in their Motorhome? OK, debate the best way to provide power to it, but not why they want to do so.
One mans meat etc .....

 

[Nabsim]

You can run the sky apps on a laptop/tablet/smartphone to get the premium channels I don’t know if that is any use to you?

 

[Deleted member 3011]

Surely wild camping is not about fretting whether satellite tv is available or not, it's more about enjoying where you are . We had a system that we got when we were tuggers, so much of a faff, so we didn't use it, when we joined this group I offered it but no responce so it got chucked, which led me to believe that wild campers, like us, are content to maybe watch telly if it's available, otherwise just enjoy each others company and do stuff like we used to do before technology kicked in.

Any other pass times and habits you feel the need to restrict us from. Perhaps smoking, or drinking? What about internet? Or eating fish and chips. Sex?