Less errors

Improves your concentration.

You decide

what time of the day it is.

No more

bad mood.

How to select power supply to power LED strip

How to select power supply to power LED strip

Some time ago a customer asked us to create a constant source of current to power LED strip.

napajalnik za LED svetila
LED strip power supply

Since the current is used to regulate the lightness of LED strip (with constant voltage) we immediately had some questions regarding power of LEDs on the strip.


moder LED trak
blue LED strip

The customer didn’t know what kind of LEDs are on the strip, only that she has 60 diodes per meter and that brightness of 240lm is needed.

After that we came to the conclusion that LED strip with power of 14.4W/m will do and for 4m of such strip, the customer will need 60W power supply.

Since the voltage need for the strip was 12V we need to take the power supply that can handle at least 5A of current, but the customer insisted to use a power supply with maximal current of 1A. Unfortunately – this does not go well with the idea of having brightness of 240lm.

So how do we select a proper power supply?

First you need to check the LED strip data. As said previously: we have 60 LEDs/m and power needed for such LEDs in 14.4W/m. Besides that – the important information is that the strip need 12V of power supply.

We have to pay attention to to the voltage of power supply. It has to be the same (or lower) otherwise we might burn the strip.

Since we selected 4m of strip we can calculate the power needed by multiplying 14.4W/m with 4m and we get needed power: 57.6W so we can look for a power supply which can produce at least 57.6W of power. Although – power supply that can produce power close to the calculated one might get overheated especially if it is enclosed somewhere, so it doesn’t hurt to go higher (but your wallet will be happy if you don’t exaggerate).

And if we are interested in value of current going through the diodes on the strip, we have to divide power with voltage (since the formula for power is voltage multiplied with current) – so 60W divided with 12V and we get 5A.

To conclude: we need power supply with at least 60W of power (or 12V/5A). It doesn’t hurt if higher currents are allowed – you only have to pay attention to the voltage. It needs to be 12V.


Comments are closed.

LED store