What is an LED power supply?
An LED power supply is a device that supplies electrical energy to an LED receiver with specific parameters that are optimal for this receiver. The features of a power supply 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 the correct and safe power supply of an LED receiver such as an LED strip or LED module. Stable power supply with a constant voltage or current will ensure long-term, trouble-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 provide us with 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 power supplies that you can come across are constant voltage power supplies, there is also a second type of constant current. Each of them for a specific application.
Constant voltage power supply
- will allow you to power most LED receivers and electronics. Thanks to the fact that it maintains a constant voltage at the output.
A constant voltage power supply is dedicated to powering:
- LED strips
- LED modules
- electronics
Constant current power supply
- a power supply that is designed to maintain only the amount of current at the output at a constant level. Constant current power supplies are characterized by a wide output voltage and constant current at the output. Constant current power supplies are designed to power POWER LEDs
Most LED power supplies are constant voltage power supplies.
Power supply operating conditions - hermetic or mesh power supply?
Depending on the application, needs and operating conditions, we can set different requirements for power supplies.
Power supplies for indoor applications
- For indoor applications where there is no exposure to weather conditions such as rain, snow, humidity, power supplies in mesh housings, so-called mounting power supplies, will work well. Power supplies in mesh are ideal for building-in, they have a low level of heat dissipation and passive cooling. Thanks to this, they are quiet and failure-free. Larger models of grid power supplies can have a built-in fan, which means that they are no longer silent. An additional feature of all power supplies in a mounting housing is the ability to adjust the output voltage.
Internal power supplies, in addition to the grid housing, can also have a housing designed for mounting on a DIN rail.
External power supplies
- Power supplies designed for operation in difficult outdoor conditions - resistant to rain, snow, water, humidity and temperature. Usually enclosed in housings with an IP67 degree, which allows for complete flooding with a stream of water. Hermetic power supplies can also have voltage or current regulation. The manufacturer of MEAN WELL power supplies in its external power supplies of the ELG HLG or XLG series places the regulation using a potentiometer hidden under a rubber plug secured with 3 seals. Despite the possibility of regulation, these power supplies still have a degree of IP65 waterproofness. Additional safety of external power supplies is also provided by the 3rd input cable - the so-called protective conductor. In the event of a breakdown, the entire current will then be received directly to the ground and the so-called differential system will disconnect the power supply.
What is the power of the power supply?
Each electrical device draws a certain power expressed in Watts (W) at a given supply voltage. In continuous operation, the power supply must have a certain power reserve in relation to the receiver. This is due to the fact that we do not always have good ventilation and the temperature of the power supply environment can be very high.
How to calculate the power of the power supply?
The power supply should usually have a 20% power reserve in relation to the receiver. So if our LED strip has 80W of power, the optimal power supply will be one with at least 100W. The warmer the environment and the less airy it is, the greater the reserve should be.
In the case of LED lighting, the power generated at start-up usually exceeds the nominal power of LED lighting. For this reason, power supplies are prepared for a momentary, much greater overload. It is also worth paying attention to power supplies that are characterized by the possibility of large overloads.
Additional functions of power supplies
Power supplies, in addition to providing stable, uninterrupted voltage, must also e sometimes perform other additional functions. Sometimes the lighting design requires the power supply to have the ability to set the voltage or dim the lighting. In devices performing work in uninterrupted continuous mode, such as servers, there is also a requirement for redundant operation. Therefore, you should consider whether the power supply you are going to choose does not have a function such as:
- - voltage regulation - allows you to regulate the voltage range by around 10% up and down
- - remote dimming - many models of MEAN WELL power supplies with the B marking 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 on 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 the power supply outputs in parallel so as to increase the overall power of the power supply system
To sum up:
A good power supply is characterized by high efficiency, numerous safeguards, high-quality components reflected in the price and at least a 3-year warranty. It is safety and reliability that mainly determine the choice of the power supply. Numerous short-circuit, overload and surge protections decide whether the power supply will allow us to sleep peacefully or to count the days until the failure expected before bed.