LED lamps are gradually replacing other lighting products from the market. These are economical, durable devices that can create a luminous flux of different shades. They differ in a more complex device than incandescent lamps. They have a built in power supply. It may be different. How the power supply for LED lamps works, which variety to choose, will be discussed later.
Power supply for LEDs
To repair the LED lamp power supply, you need to understand the principle of operation of such a system element.
The power supply of such a lighting device must meet a number of requirements. The main ones are as follows:
- energy efficiency;
- reliability;
- electromagnetic compatibility;
- safety.
Only by providingLED power supply with the listed qualities, you can achieve the correct operation of the device, extend its life.
It is worth noting that the duration of operation of the presented lighting devices is at least 50 thousand hours. Accordingly, the power supply should work for no less time. At the same time, it must be remembered that the main reason why LED lamps are replacing all other types of lighting devices is energy-saving technologies. Therefore, the power supply must also have a high efficiency. Otherwise, there will be little energy savings due to the power supply.
It is also worth noting that the part shown is the only source of electromagnetic interference. Therefore, the compatibility of the LED lamp with the mains depends on the power supply.
The only element in the presented lighting device, which is supplied with voltage from the household network, is the power supply for LED lamps. 220V in this element of the system is transformed, decreasing to 12 V at the output. For this reason, the electrical safety of the device is completely dependent on this device.
In addition, the power supply affects the lighting characteristics of the lamp, on what current will flow through the LED. If it pulsates, then the luminous flux will also be of poor quality, badly affecting vision.
Lamp device and driver
The power supply for the 12V LED lamp is the most common variety. Depending on the characteristicsit can produce lamps at the output of 5, 12, 24, 48 V. In this case, the current is converted from alternating to direct. This is a prerequisite for the correct operation of the system.
Before considering the device of this lamp element, you need to pay attention to its place in the design. This will allow repairs to be made if necessary. LED type lamps have the same device. If you dismantle the case, you can see the driver inside. This is a printed circuit board on which radio elements are soldered.
The base of the presented devices most often has a G4 size. The power supply for LED lamps follows immediately after it. Electricity is supplied to the contacts of the cartridge, transmitted to the terminals of the base. Two wires are connected to it, through which voltage is supplied to the driver (power supply). Here, the current is transformed to the specified parameters. It goes to the board to which the LEDs are soldered.
Driver is an electronic unit, which is a current generator. It, in turn, also has several main components. The voltage from the household network first enters the filter. It eliminates electromagnetic interference. Next, the current goes to the rectifier. Here it becomes permanent. The next stage of the power supply is designed for power factor correction. The last stage that the electric current passes through in this device is a pulsed current stabilizer. LEDs are connected to its output.
Any LED lamp has such a device. If you need to assemble power suppliesLED lamps for emergency or general use, adhere to the specified scheme.
LED Power Features
The 220V LED lamp power supply has some work features. This must be taken into account when planning to make or repair this device. The LED has a non-linear relationship between voltage and current. All lighting devices of the presented type have this feature.
So, with an increase in the nominal voltage, the current on the LED increases sharply. This may lead to breakage. Therefore, in inexpensive lamps (often of Chinese origin), a limiting resistor is installed in series with the LED. If there is a voltage surge, it will not allow the current to increase. But in this case, the power will drop across the resistor. For this reason, the efficiency of an inexpensive lamp decreases.
The power supply provides normal voltage to power the LEDs. It is this device that is most often included in the scheme of lamps of the type presented. The power supply for a 12V LED lamp or with a different output voltage value is called a driver. This is the marketing designation of such devices. A constant voltage source for LEDs that operate on 12 V is commonly called a power supply. If the device also stabilizes the input current, then this is a driver. We can say that this is a kind of power supply that is installed in high-quality lamps.
Varieties of power supplies
After considering the block devicepower supply of the LED lamp, you need to pay attention to the varieties of such devices. They can be transformer or pulse. They differ in device and principle of operation.
So, a transformer is used at the heart of the transformer unit. This is a step down device. The voltage for any LED type lamp must be reduced from 220 V to 12 V or another desired value. Only after that the current is supplied to the rectifier. Any LED lamp is powered by direct current.
The advantage of transformer varieties of devices is the simplicity of their design. They are able to withstand the load in idle mode and are isolated from the household network. However, the presented version of the block also has disadvantages. The main ones are low efficiency (50-70%), as well as the sensitivity of the system to overloads.
Switching power supply for LED lamps also has a transformer in its design. But in this case it works at higher frequencies. Therefore, its weight and size are several times smaller. A conventional transformer power supply operates at a frequency of 50 Hz. It is much larger. The efficiency of the impulse device is 70-80%.
In the pulsed varieties of the device, there is also an isolation from the network. This device is also sensitive to overloads, but it may stop functioning even at idle. Such a device with a significant overload can ignite.
Driver Features
Choosing a power supply for an LED lamp220 V, you need to pay attention to the features of devices that are commonly called drivers. These are switching types of power supplies. They stabilize the outgoing voltage that is applied to the LEDs. Such devices are single- and two-stage. The second option is preferable. Two-stage drivers are installed in the vast majority of circuits. They have a special operating principle.
So, the first stage is a power factor corrector. The second element of the system is the output voltage stabilizer. The corrector block is necessary, since the driver is a pulsed device type. It must comply with the requirements stipulated in GOST, which relate to the suppression of harmonics in the input voltage.
Two-stage driver complies with the standards and requirements that are put forward to the quality of the luminous flux. Such a power supply for 12 volt LED lamps is capable of providing a ripple equal to 1%. This is a good indicator. Such lighting will not adversely affect the vision and nervous system of a person. In this case, the power factor of a two-stage device is 0.92-0.96.
It is worth noting that the presented driver circuit is quite expensive. Therefore, manufacturers of cheap lamps install a single-stage driver circuit. Such systems are more suitable for creating lighting in a pantry, technical room, basement or entrance. In an apartment or house, you need to use two-stage schemes.
A few more words about drivers
Worth itIt should be noted that unlike the power supply, the driver does not have such a characteristic as “outgoing voltage”. This device is characterized only by indicators such as output current and power. This means that the presented type of power supply will not provide a current with a higher value than was calculated by the manufacturer.
There are drivers designed for a certain number of LEDs (for example, 5 pcs.). In this case, you can connect fewer lighting elements, but not more.
Other types of lamp circuit elements presented can work with any number of LEDs. However, their total power should not exceed the value set by the manufacturer. It is worth noting that universal drivers will have less efficiency. This is due to the specifics of the operation of the pulse circuit.
Varieties of drivers
There are several types of power supplies presented for LED lamps on sale. The main ones are as follows:
- capacitor circuit;
- resistor;
- driver with low voltage type input;
- chip HV9910;
- network driver;
- LM317 chip.
The choice depends on the features of the device, the parameters of its operation.
Expert Tips
When choosing a power supply for LED lamps, you need to know how their existing types differ. Experts in the field of lighting technology give some advice. Mastersclaim that when used in a driver circuit, LEDs can operate at full power. This is due to the lack of need to lower the voltage. In this case, the LEDs will not fail due to power increase.
If the power is supplied by the power supply, part of the voltage will be consumed due to the heating of the resistors. The latter are responsible for limiting the voltage during a jump in current indicators. Therefore, by powering the system with a driver, you can significantly extend the life of the LEDs. The current in this case will never exceed the allowable value.
It is worth considering that the driver is a device that is designed for current with certain characteristics, a given power. Therefore, if you want to assemble or repair a power supply from an LED lamp with your own hands, you need to select it in accordance with the number and type of LEDs. Their power must correspond to the selected power supply.
The conventional power supply can be used for any electrical appliances, and the driver is specifically designed for LEDs. This must be taken into account when buying a device. There are a number of factors that influence the choice of power supply type.
Which type of device should I choose?
The power supply for LED lamps, as well as drivers, must be selected in accordance with the characteristics of the operation of the device. Experienced craftsmen give some advice on what kind of power supply is better to purchase in a particular case.
It is preferable to use the driver in a circuit with LEDs, if the circuit does notresistors are provided. This happens if you need to power individual diodes. Also, the presented variety of devices is used if it is not necessary to periodically disconnect some of the LEDs from the driver.
Also, in specialized stores it is easier to choose an input voltage stabilizer. The driver is selected according to the number of LEDs and their power. A qualified sales consultant should help with this. Therefore, when purchasing the necessary equipment in the store, it is better to opt for a driver.
If the circuit provides LEDs with built-in resistors, it is better to purchase a power supply. This solution will also be correct in cases where it is sometimes necessary to turn off some of the LEDs.
Selection Tips
Experts advise to approach the choice of power supply for LED lamps comprehensively. Turning to a specialized store, you must first determine the type of power source. Having decided whether a driver or power supply is needed, you can proceed to the next step. The total power of the LEDs is determined. The power supply must not only meet this value, but also have a margin of about 20%. To calculate the power, you need to look at the data sheet of the lamp.
The driver must match the rated power and current of the LEDs. A power supply that outputs 12 volts will not work for a 48 volt lighting fixture.
Next, you need to pay attention to the indicator of protection of the body from external weather conditions. You need to decide for what purpose you need a lamp. If she willmounted outdoors, in a damp or dusty room, the protection class must be high. This indicator is indicated by the letters IP in the marking. For home use, you can choose the power supply with the lowest protection class. IP65 type devices are designed for outdoor installation or indoor bath, bath or shower. Such a power supply is not afraid of a direct hit of a jet of water on the case. The cost of secure devices is an order of magnitude higher.
