Choosing the right LED power supply
LED lighting is increasingly used in homes, offices, shops and other places due to its advantages, such as low energy consumption, long life and the ability to control colors and brightness. However, to properly connect and power LED lighting, you need to choose the right power supply that will provide stable and safe voltage and current for the LEDs.
A LED power supply is an electronic device that converts mains voltage (usually 230 V AC) to a DC voltage (usually from 5 to 48 V DC) of a specific value and power. The power supply must be matched to the LED lighting parameters, such as operating voltage, operating current and total power. The power supply must also meet safety and quality standards, such as CE, IP and RoHS certificates.
How to choose an LED power supply? What to look for?
First of all, we need to determine the type of LED receiver. LED receivers such as strips or single low-power diodes can be successfully powered with constant voltage power supplies, e.g. 12V. It will be completely different for Power LEDs, which heat up a lot - in this case, you should use a constant current power supply. Let's discuss the power supply for each of these receivers:
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Power supply for LED strips
To power the LED strips, we will use a constant voltage power supply. However, we need to determine such features of the LED strip as voltage and power.
Supply voltage
- strips cut every 3 diodes are powered by 12V while strips cut every 6 or sometimes 7 diodes are powered by 24V.
This results from the fact that a single diode is usually powered by a voltage of 3 - 3.3V, so the so-called section, i.e. cut every 3 diodes, is nothing more than three pieces of three-volt diodes connected in series to obtain a total of 12V. And the entire LED strip is in a way a power line to which subsequent three-diode sections are connected in parallel.
Power
- the product of meters and 1m power (although not exactly). The power of the LED strip is usually given by the manufacturer on the packaging, but a good practice will be to connect a piece of LED strip in series to a current meter and check by gradually increasing the voltage to the recommended one and measuring the current consumption on this section. It is usually best to check the LED strip consumption on a 5m roll with double-sided power supply. This method of measurement will eliminate voltage drops and show the actual current consumption. This value should be mapped to the length of the LED strip you want to power.
Remember the power reserve
If we have already calculated the power of the strip, let's add a 20% reserve. Especially in difficult conditions such as lack of air circulation or non-stop operation, we should remember the power reserve.
How to choose a power supply - if we already know the power and supply voltage, we can easily choose one of the constant voltage models in the wide range of Mean Well power supplies. In this case, the first number in the model designation determines its power and the second number the supply voltage. Go to the group of constant voltage power supplies and select the model according to the power and voltage - MEAN WELL Power Supplies for LED Strips
Main problem - voltage drop
The method of connecting LED strips to power supplies or controllers is also important. A high-power LED strip powered on one side in a long section draws less current than the same strip cut into shorter pieces connected in parallel to the power supply. The reason for this is a voltage drop with distance from the power supply.
To avoid voltage drops in the case of strong LED strips:
- do not exceed too long sections
- power the LED strips from both sides
- choose 24V solutions
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Power supply of Power LED diodes and LED matrices
Power supply of high-power LED receivers is associated with a completely different problem to solve, namely the spirally increasing power consumption due to the change in resistance caused by a large change in the temperature of the LED chip. A heating power diode emits so much heat that after heating up, its current demand at the same voltage can be even several times higher. This situation leads to further heating of the Power LED diode and, as a result, its burnout. That is why constant current power supplies are required for high-power LED receivers.