Finding the right LED Power Supply for your LED Strip

A common question arises from customers: “How do I calculate the right power supply for my LED strip?” 
 
The answer isn’t hard to find, follow the next few steps:

Step 1. Check the data sheet of the LED strip you intend to use.

In the data sheet, you can find the power consumption typically in Watts/Metre.     

• For example, it can be shown as “14W / m (14 Watts / Metre). 
   

Step 2. Determine Length in Metres & Multiply by the Wattage.

Calculate the length of the strip you intend to use in metres and multiply this number by the number of Watts used per metre. 

Example:

• 8.5m of LED Strip consumes 14W / metre. 
• 8.5 x 14 = 119W 

This determines that you will need an LED power supply with a minimum power output of 119W. However, be mindful to make allowances for unintentional overloads. To prevent this, it is typically recommended only to use 80% of the power supply’s rated load output. So in this example, it would be recommended to utilise a 150-watt power supply.

Step 3. Confirm The Power Supply’s Output

Once you’ve determined your required power, confirm your intended power supply meets your requirements from the product data sheet. The power output does vary from model to model within a series.

Example:

• HLG-240H-24 has a power output of 240 Watts, whereas the HLG-240H-12 has a power output of 192 Watts. 

Step 4. Other Considerations – Dimmable LED Driver

If you are considering using a dimmable LED driver, you may need to consider some additional factors before making a purchase.  
 
Dimmable LED drivers provide dimming by manipulating the amplitude of the current delivered to the LED strips. If you are using more than one power supply to power multiple LED strips, the load on each driver must be matched as closely as possible to keep dimming synchronised.  
 

Example:

• If one supply is loaded to 80% and another power supply is loaded to 50%, the first supply will start to dim once the dimming protocol is turned down below 80%. However, the second power supply won’t begin dimming until the dimming protocol drops below 50%. This difference in dimming is very noticeable to the eye. 

 
If your dimmable LED power supply has a PWM type output (Pulse Width Multiplier), such as the MEAN WEL PWM series or Power Source TRIAC Dimmable LED Driver, it will dim evenly regardless of load. LED Supplies Australia sells these LED drivers in 12V and 24V models.  
 

If you have any questions or concerns about finding the right power supply for your LED strips or wider LED installation, the LED Supplies Australia team is here to help. Please send us your questions via our contact page here, or call us directly on 1800 632 693.