Hi all, I've bought some LED tape which I fitted in aluminium channel under the kitchen cabinets. It's classed as 12v but gets very hot, almost too hot to touch so I've put 2 diodes in series which has dropped the voltage to around 10.5v. It's nearly as bright but the current has halved and they are only just warm. My question, is it more efficient to use the 2 diodes or a current limiting resistor?

Thanks

 

Exactly the same.

Bob

 

But with diodes, if he changes the length of the strip, he won't have to change the diodes, the voltage drop will be pretty consistent, but with resistors, he would have to know the desired total LED strip current and recalc the resistor values. Diodes are simpler...

 

But with diodes, if he changes the length of the strip, he won't have to change the diodes, the voltage drop will be pretty consistent, but with resistors, he would have to know the desired total LED strip current and recalc the resistor values. Diodes are simpler...

Welcome fo AAC.

That is an advantage, if he ever changes the number of LEDs for some reason, but it doesn’t make them more efficient in the sense the TS intended.

 

What are you using to deliver the 12VDC required?

You have two options:
1) if it is a wall adpater, replace it with one that outputs a lower voltage.
2) use a buck switching regulator.

 

What are you using to deliver the 12VDC required?

You have two options:
1) if it is a wall adpater, replace it with one that outputs a lower voltage.
2) use a buck switching regulator.

There are 2 strips on switching 12v LED power supplies , actually one broke the other day so I'm temporarily using my bench power supply for one. The new supply I ordered has got a preset voltage adjuster on it and I'll leave the 2 diodes on the other.

 

Are you able to accurately measure the voltage that you are sending to the LED strip? Many block-module supplies are unregulated and only deliver the claimed output with the specified load current. That may be a part of your problem.

 

s nearly as bright but the current has halved and they are only just warm.

Why not install a dimmer made for those strips that use PWM?
8 bucks from Amazon.