What is an LED power supply?

The LED power supply is a device that supplies electricity to the LED receiver with specific parameters optimal for this receiver. The features of a power supply unit are usually its output parameters, i.e. voltage, maximum current and total power. Stable parameters of the current coming out of the power supply are the basis for proper and safe power supply of an LED receiver such as an LED strip or LED module. A stable power supply with uniform voltage or current will ensure long-term, failure-free operation of the LED receiver. In addition to stable power supply for LED receivers such as strips or modules, a good power supply will ensure safety and reliability. A good safe LED power supply has systems that detect errors such as overload, short circuit or overheating.

How to choose an LED power supply?

Constant voltage or constant current power supply?

First of all, the choice of power supply is related to the type of receiver we want to power. Although in practice most of the power supplies you come across are constant voltage power supplies, there is also a second type - constant current. Each of them for a specific use.

Constant voltage power supply

- will power most LED receivers and electronics. Due to the fact that it maintains a constant voltage at the output.
The constant voltage power supply is dedicated to powering:
- LED strips
- LED modules
- electronics

DC power supply

- a power supply whose task is to keep only the amount of current at the output constant. DC power supplies feature a wide output voltage and constant output current. Constant-current power supplies are designed to power POWER LEDs
  
 
Most of the LED power supplies used are constant-voltage power supplies.
  
 

Power supply operating conditions - hermetic or mesh power supply?

Depending on the application, needs and operating conditions, we can impose different requirements on power supplies.
 

Power supplies for indoor applications

- For indoor applications where there is no exposure to weather conditions such as rain, snow or humidity, power supplies in a mesh housing, the so-called mounting power supplies, will prove useful. Mesh power supplies are ideal for built-in installations, have low heat generation and passive cooling. Thanks to this, they are quiet and failure-free. Larger models of mesh power supplies may have a built-in fan, which makes them no longer silent. An additional feature of all power supplies in the mounting housing is the ability to adjust the output voltage.

In addition to the mesh housing, internal power supplies may also have a housing designed for mounting on a DIN rail.

External power supplies

- Power supplies designed to work in difficult outdoor conditions - resistant to rain, snow, water and humidity. temperature  Typically enclosed in IP67 housings, allowing for complete flooding with a stream of water. Hermetic power supplies may also have voltage or current regulation. The manufacturer of MEAN WELL power supplies places the regulation using a potentiometer in its external power supplies of the ELG HLG or XLG series, hidden under a rubber cap secured with three seals. Despite the possibility of regulation, these power supplies still have an IP65 waterproof rating. Additional safety of external power supplies is provided by the third input cable - the so-called protective wire. In the event of a breakdown, the entire current will be received directly to ground and the so-called differential system will disconnect the power supply

What is the power of the power supply?

Each electrical device at a given supply voltage consumes a certain power expressed in Watts (W).  In continuous operation, the power supply must have a certain amount of power in relation to the receiver. This is due to the fact that we do not always have good ventilation and the ambient temperature of the power supply unit can be very high.

How to calculate the power of a power supply?

The power supply should usually have a 20% power reserve in relation to the receiver. Therefore, if our LED strip has 80W of power, the optimal power supply will be at least 100W. The warmer the environment and the less breathable it is, the greater the supply should be.

In the case of LED lighting, the power generated at start-up usually exceeds the nominal power of the LED lighting. For this reason, power supplies are prepared for momentary, much higher overloads. It is also worth paying attention to power supplies that are capable of high overload.

 
 

Additional functions of power supplies

In addition to providing stable, uninterrupted voltage, power supplies sometimes must also perform other additional functions. Sometimes a lighting design requires the power supply to be able to set the voltage or dim the lighting. In devices performing continuous work, such as servers, there is also a requirement for redundant work. Therefore, you should consider whether the power supply you are going to choose does not expect a function such as:
 

• - voltage adjustment - allows you to adjust the voltage range around 10% up and down
• - remote dimming - many models of MEAN WELL power supplies marked B at the end of the symbol have the ability to control power via a signal
• - remote switching on - some power supplies have a remote switching function - it eliminates the operation of the power supply in idle mode
• - parallel operation - although power supplies should never be connected in parallel, a few MEAN WELL models allow you to connect power supply outputs in parallel so as to overall increase the power of the power supply system

 

Conclusion:

A good power supply is characterized by high efficiency, numerous protections, high-quality components reflected in the price and at least a 3-year warranty. It is safety and failure-free operation that mainly determine the choice of a power supply. Numerous short-circuit, overload and breakdown protections decide whether the power supply will allow us to sleep peacefully or count the days until a failure is expected before going to sleep.