LED Lights - Transformer and Lights getting very hot

[Andrew Rush]

Hi All

Help...

I have a strip of SMD 5050 LED lights - plugged in to a 12v transformer - and both (the LEDs and Transformer) get very very hot to touch. They take about an hour to slowly get up to the high temp - and sit there at that high temperature. The strip has been cut from a 5m length - down to 3.5m.

So my logic is this -
- each light draws 0.24 watts
- 60 lights per meter
= 14.4 watts per meter
- 3.5 m strip
= 50.4 watt total

So the 12v transformer needs to be rated to 4.2 Amps. I am using a 5 Amp transformer.

Have I got the above correct ?
Can anyone shed any ideas on why they are both getting so hot ?

Thanks

 

[James]

When you say hot, how hot?
Many plug in transformers are designed to run up to 50degree C
The transformer is at near full load so will be running close to its design temperature.

 

[Marvo]

When you say transformer, is it an LED driver or is it actually a transformer?

The wattage of the individual LED chips is usually a nominal rating, it's a bit dangerous to calculate the power of the strip by basically multiplying the wattage of one of the LED chips by 210. It would only require a very small error on the single chip wattage to give a very large error on the total wattage (the error would also be multiplied by 210).

Also I'd usually specify a driver that can deliver at least 1.5 times the Watts stated on the LED strip.

 

[GeorgeCooke]

When you say transformer, is it an LED driver or is it actually a transformer?

Of course it won't be a transformer. Transformers are AC devices. LED strips require DC. Unless, of course he is using a transformer then I would not expect the LEDs to last long.