Hello eveybody, in this video I’m going to tell you how to know which transformer you have to choose for your led strips and what minimal power must it have. There are many types of led strips, but we will focus in the two types that are more common, they work with 12 volts, the type 3528 and the led strip 5050. As you can see the 5050 brights more and it can be used as indirect lighting, whereas the 3528 has less power and lights less, it is usually employed for ambient lighting. I’ll talk about the 2835 led strip at the end of this video. The first step to calculate the power is to identify which type of led strip you have, check out your order or its packaging to know it. You can also know it seeing its leds, in the 3528 type the leds measure 35 x 28 milimeters, they have rectangular shape, very small, and each led consumes 0,08 Watts or 0,0066 Amperes. In the 5050 type the leds measure 50 x 50, they are square, each led consumes 0,24 Watts or 0,02 Amperes. Now that you know how to identify the led strip the power calculation is very simple.
You just have to multiply the number of leds by the power of each led. You have to options. First option, very useful for short led strips, to count the leds that are in the strip and multiply that number of leds by the power of each one. In this first example we can see a 3528 led trip which has 60 leds, so I will need a transformer with the power you see on screen, I multiply 60 leds by 0,08 watts and I obtain the power value, 4,8 watts.
Or, if I want to calculate it as current or intensity, it would be 60 led multiplied by 0,0066 amperes, so the total is 0,4 amperes, Check out that I’m using the 3528 led strip type power values, and remember that the current can also be calculated dividing the power by the voltage or tension, 4,8 watts divided by 12 volts that would give us the same 0,4 amperes. If we measure it with a power measurement device, the calculus seams accurate. So with that data, you can choose among the different available transformers, choosing one with a 20% more power than the calculated, to avoid a possible overheating in the transformer. To calculate that additional 20%, multiply by 1,2, since we had a current of 0,4 amperes we will obtain 0,48 amperes as minimal current for the transformer. We could then choose a transformer of 1 ampere or 12 watts, or even less. Second option, instead of counting every led in the led strip, you can just count the leds the first meter of led strip and multiply by the led strip lengh in meters to obtain the power. Here you have a second example, there is a 5050 led strip of 2 meters lenght, if we count the leds in the first strip meter there are 30, so in total I will have 2 meters multiplied by 30, which gives a total of 60 leds.
So I’m ready to calculate the power, in this case using the power for 5050 leds type, the result would be 14,4 watts or 1,2 amperes. In the power measurement device we obtain a power similar to the calculated. Since we have a power of 1,2 amperes in the calculus, if we multiply it by 1,2 to add the 20% margin we obtain 1,44 amperes. We would choose a transformer of 2 amperes or more. As you see making the calculus is very simple, anyway I leave you here two charts with the approximate power for the 3528 led strip depending on its number of leds.
And the power estimation for the 5050 led strip type. To finish, remember not to connect more than 10 meters of led strip continuously. In this Youtube channel you have other video with information.
