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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> led lights https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1319918823 Message started by benella on Oct 29^th, 2011, 9:07pm

Title: led lights
Post by benella on Oct 29^th, 2011, 9:07pm

how many 5 w mr16 led can you power on a 60va /12v toroidal tranformer.

Title: Re: led lights
Post by CWatters on Oct 29^th, 2011, 10:18pm

I've seen 4W LEDs rated 5VA.

On that basis I guess a 5W LED could be around around 6.5VA so a 60VA transformer should be ok for 9 LED.

Title: Re: led lights
Post by CWatters on Oct 29^th, 2011, 10:28pm

Oops looks like the power factor could be worse..

http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/mr16_benchmark_11-08.pdf

Quote

..testing to date, power factors for LED MR16 replacement lamps have ranged from 0.57 to 0.77, with an average of 0.63,

On that basis might be safer to go with 60x0.57/5= 6

Perhaps see what others think.

Title: Re: led lights
Post by benella on Oct 30^th, 2011, 11:41am

ok, thanks for the reply.