transformers 240-12volt
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transformers 240-12volt

by m88arx » Mon Jan 12, 2009 12:45 pm

how many 12volt lights can be controlled by a 20-60 watt transformer i want to put 5 lights in screwfix par no is 98011 they come in packs of 3 but wanting to know if i can run 5 of the lights with the one 12 volt transformer whihc is 20-60 watt

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by stoneyboy » Mon Jan 12, 2009 11:09 pm

No definitely not. Each lamp is 20w X5 makes 100w. Transformer is good for 60w max. Buy a more powerful transformer or just two of them.


by ericmark » Mon Jan 12, 2009 11:25 pm

I will agree the advert is very confusing it says "No transformer required" and the G4 does refer to base rather than voltage but only bulbs I can see for sale with screwfix with G4 base are 12 volt. So I would think there is a miss-print? Or does it mean no extra transformer required as one is in kit? They also list the 2 x G4 bulbs they have for sale as "low voltage" which means 50 to 1000 volt but when you read further it says 12 volt which is "extra low voltage" so seems who ever made their catalogue has no idea!

12 volt transformer which is 20-60 watt is not a simple transformer but an inverter for use this means lighter than transformer and may also correct voltage if not spot on but has a minimum wattage.

It is simple maths 60 divided by 20 goes 3 times and bulbs smaller than 20 watt should not be used as if they blow you will end up below min wattage.

The G4 lamp is available as 6, 12, 24, and 28 volt and as 12 volt as 5, 8, 10, 20 and 35 watt so if 12v 10w bulbs were used it could work up to 6 lamps with the inverter (transformer) you talk about but you would have to be careful to renew bulbs when they blow and never let it run with only 2 bulbs in case last one was to blow and damage inverter.

Although I see no 10w bulbs for sale from screwfix you will need to go else where to get bulbs.

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by singer » Tue Jan 13, 2009 2:41 am

Hi m88arx

Have looked at the lights you have bought from screwfix.
If you look at all 4 photos it shows a transformer is provided with the kit.
It states 20 watts max each light so you would assume the lamps provided are 20 watts each.
The transformer provided is therefore only big enough to supply the 3 lights supplied in the kit.
You say you want to install 5 lights in total which will involve buying another 98011 kit which will have another transformer in it to connect the other 2 lights to.
Job done

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