Aerial Booster from Lighting Circuit

[diynoob]

I have an aerial in the loft which I'd like to plug in to boost the signal. It has a plug, labelled with output 12v, 150mA. The upstairs sockets are very far away so powering from the lighting circuit would be more convenient.

I've seen post before advising not to add a socket from the lighting circuit even for such low power requirements since future users may plug a heater into the socket for example.

What about a FCU off the light with a small fuse in it? The plug on the aerial is moulded though so I can't connect directly to a FCU.

 

[holmslaw]

..

 

[diynoob]

Are you sure its OK to replace the aerial's plug like that. Its labelled 12v, so doesn't that mean its a transformer rather than just a plug with a fuse it it?

 

[Space cat]

-- replade the fuse with the one in the aerial plug top.

If I read the original post correctly, the 'plug' is a plugtop PSU so its internal fuse will almost certainly be sealed in. Get a cheap two-gang extension lead, replace its fuse with a three amp one, cut the plug off and wire it into the lighting circuit. If, as I suspect, this thing will be lying in a loft where nobody ever goes, an additional FCU is not required but a nice clear label saying "THREE AMPS ONLY" would be a good idea.

Edit: I've just seen this --

Are you sure its OK to replace the aerial's plug like that. Its labelled 12v, so doesn't that mean its a transformer rather than just a plug with a fuse it it?

Absolutely! DO NOT put a mains plug onto the end of that lead. You're quite right; it's a plug-in transformer (with or without rectification and voltage regulation) and the lead is its low voltage OUTPUT. Connecting that to the mains supply is pretty well guaranteed to blow it up.

 

[diynoob]

Thanks, I'll leave the existing aerial plug well alone. I have a spare FCU so its no bother to use that and replace the fuse with a 3A fuse. I'll run a socket from that and label it 3A only.

What cable shall I use to connect the fcu to the light and from the fcu to the socket? 1.5mm or 2.5 mm?

 

[Space cat]

1.5mm is more than adequate for a lighting circuit. 1mm would be big enough.