DC voltage reduction

[tosher]

Is there a simple way to power a 6volt appliance from the boats 12volt DC sockets? I have a digital TV aerial which has an internal booster. This booster is supplied with 6volt DC from a power inserter plugged into the aerial coax cable at the back of the freeview box. This power inserter is supplied from a 240volt AC plug with built in transformer/rectifier but unfortunately the nearedt 240 volt socket is some way from the TV which means trailing cables. Right next to the TV is a spare 12 volt DC socket so my question is ---- how can I supply the 6 volt DC power inserter from the adjacent 12 volt DC socket ?? The details on the power inserter say 6 volt DC 100ma but the actual measured voltage when plugged into 240 AC is 8 volt DC.

[PeterF]

If it is a low power item which I suspect it is you can get small power converters from Maplins that have a settable output voltage from something like 6V to 12V. I have used a couple of these on my boat and they appear to work well. One powers a 12V appliance that stated it would not want the 14.8V in the system during battery charging and the other 9V. The only problem is that they may have a low efficiency at low current draw.

 

It is called a universal DC power supply and can be found on

 

Universal DC power supply

 

If you do not have a cigarette style socket then it is easy to cut the feed cable as long as you make sure you get the +ve the right way, it is the one which feeds the central tip of the plug.

[wonderdust]

Don't no if this would do the job? clicky

[ChrisPy]

can't you wire it up twice , in series with itself , so it gets half the voltage twice ?? ................................. er ... no. damn !

[Yoda]

can't you wire it up twice , in series with itself , so it gets half the voltage twice ?? ................................. er ... no. damn !

 

What are you on?! Too much Turkish coffee?

[Keeping Up]

The Maplin power supply looks useful; I don't think I'd trust the VW Beetle thingy

[ChrisPy]

What are you on?! Too much Turkish coffee?

No, I'm finished with Turkey, I'm looking forward to curries now

[chris w]

The details on the power inserter say 6 volt DC 100ma but the actual measured voltage when plugged into 240 AC is 8 volt DC.

 

The Maplin type converter will do fine. The reason you're reading 8v DC, rather than 6v, is because you are measuring the converter off-load. Once on-load the current drawn will pull the voltage down to 6v. A well regulated converter would not do this but for cheapness many are not well regulated.

 

Chris

[tosher]

Thanks for all your responses, I bought the Universal DC Power Supply from Maplins as suggested and it does the job nicely. Cheers -- tosher.