What diodes are in LED lamps. How to check and replace the power supply of LED lamps. Finding faulty LEDs

Implementation projects are increasingly incorporating LED components. LED devices have gained widespread popularity due to significant energy savings and durability, although their cost still exceeds the price tags of more conventional energy-saving and halogen lamps. But LED technology has many other advantages due to its unusual design. A typical 220 device, the photo of which is presented below, is free of massive radiation sources, which allows the body to be optimized in size and performance characteristics. As a result, such qualities as wide functionality, increased control ergonomics and ease of installation are achieved.

Diode crystal as the basis of a lamp

The basis of any LED device is formed by one or more semiconductor elements that convert electricity into light radiation. These are diode crystals, most often made in the form of a miniature chip. On a small platform of the board there is also equipment for connecting power wires. However, a 220 V device may involve the use of different crystals that differ in design and set of functional components:

DIP. The most common one is on the surface of which a lens and two conductors are placed.
SMD. A universally applicable crystal, characterized by its modest size and effective heat dissipation.
"Piranha". Diode crystal with four outputs for occasions. This configuration makes the emitter more efficient and reliable in operation.
OWL crystal. IN in this case The diode is integrated into the board, thanks to which the contacts are better protected from overheating and oxidation. At the same time, the intensity of the glow increases.

Basic design of a 220 V LED lamp

In addition to diode crystals, the design includes a base, diffuser, radiator and housing. The board itself with LED elements is the functional core, which is served by the listed components. As for the base, it acts as a supporting link that allows you to integrate the lamp into the socket suitable size. The scatterer makes the photon radiation (converted from the current) more saturated and directed. In more modern versions it is possible to change the physical parameters of the light supply, which is achieved precisely by adjusting the parameters of the diffuser. The radiator unit is also essential in the design of a 220 V LED lamp. One of the main advantages of LED devices is the absence of heating of the housing, which makes the source fireproof. This property is provided precisely by the radiator, which performs the task of heat removal.

Features of low-power lamps

The entry level in the segment is represented by compact devices with 2-4 crystals. The power of each emitter varies from 2 to 5 W. Unlike full-size models, such lamps are characterized by the presence of a plastic body (in conventional designs glass covers are used), a modest length of about 15 cm on average and a weight of 50-70 grams. At the same time, the design of low-power 220 V LED lamps also requires the presence of radiator units. These can be massive metal modules, the task of which is to protect the plastic case from overheating and melting. In this case, the requirements for heat dissipation are much more stringent, so the size of the radiator is often larger than in high-power LED lamps. As for the quality of radiation, users note the dimness of the light, more gravitating towards bright white and cold spectra.

Lamp shapes and sockets

Especially when choosing non-standard designs, it is important to calculate in advance the possibility of combining a lamp with a lamp in the form of a chandelier, sconce, floor lamp, etc. The most popular form factors include the following:

LED pear. Standard design that resembles classic incandescent lamps. For such models, E27 type sockets are selected.
Candle shape. It is on this housing that the device of low-power 220-volt LED lamps, including E14 and E27 sockets, is based. Similar designs are often used in wall lamps and small chandeliers.
Tubular shape. This is already a non-standard version of the lamp, marked with the designations T3, T4, T20, etc. However, the external resemblance to fluorescent lamps does not in any way transfer to the internal filling, much less to the working qualities.
Ball-shaped models. For such devices, bases G45, G60 and G80 are used, which can be integrated into different types of luminaires, both open and closed.

Control driver device

This component is not always used, but 220-volt models are the target devices. For them, devices with the HV9910 chip are usually used, which can be powered from a network with a voltage of 8 to 450 V. The chip itself acts as pulse source, equalizing the current. If you plan to use alternating current for power supply, then the 220 V LED lamp driver device will also have to include a rectifier - for example, a bridge type. In common configurations of this type, the HV9910 driver also works in combination with external transistors.

Features of “Armstrong” type structures

The commercial use of lighting devices places high demands on the supporting structures into which the lamps are integrated. This is due both to the need to improve protective qualities and to technical optimization installation process. On at the moment Such problems are solved by Armstrong-type platforms, which are a ceiling structure designed for several powerful radiation sources. Unlike standard models, the 220 V LED lamp device for the Armstrong design has the following characteristics:

Clogging the lamp into a plastic monolithic housing.
The use of technologically primitive drivers (in order to reduce the cost of design) or their complete absence.
Using one radiator for several lamps.
Typical design of the supporting platform, which involves the provision of standard plinths.

Lamp control system

Modern LED devices are equipped with dimmers, through which you can adjust the operating parameters of the lamp. In particular, the user can set brightness parameters. Some versions also include programming elements. Using the built-in timer, you can set the time, glow modes and work sessions with specific glow characteristics. A typical device for a 220 V LED lamp with a dimmer also includes a stabilizer. The fact is that the brightness is adjusted by cutting the voltage and to reliably perform this procedure, a stabilizing component is required. Also to ensure safety in conditions maximum power A safety unit is often used, the range of functions of which includes automatically turning off the device or switching it to a balanced operating mode.

How to make your own LED lamp?

The simplest technique for making this device is based on a burnt out or unnecessary fluorescent lamp. It is necessary to disassemble its structure, removing the base with the reflector. These parts contain the most important elements from the point of view of the device, the entire electrical circuit is disassembled, during which the fuse should be removed from the reflector, as well as diode crystal. Actually, the new lamp will be based on ready-made lighting equipment, the filling of which can be assembled using an electrolyte. But before this, you should add to the configuration a capacitor unit capable of withstanding at least 450 V, and better yet, 630 V. And if there are not enough LEDs, they can be taken from an LED strip. The main thing is to choose components of appropriate power. The assembly of the structure is carried out using superglue or a compound with suitable characteristics.

Lamp installation

The installation approach will depend on the design of the luminaire. The most difficult in terms of installation are ceiling structures, in the niches of which a lamp is integrated. These are high-power point devices that subsequently operate without lampshades. That is, a barely noticeable part of the optical emitter remains on the surface of the tension or hanging installation. For ease of installation, a 220-volt LED lamp of this type provides fixing rings and clamps. With the help of this fittings, the housing is fastened to the ceiling niche. But before this, an electrical line with a socket into which it will be screwed must be connected to the placement point on the side of the frame. Next, the mounting hardware with the lamp is immersed and closed into the hole made in the hanging or tension fabric.

Maintenance minimizes the risks of capital repairs with replacement of diodes. This point can be delayed in time by regularly cleaning the device and updating consumables. If during operation of the device there is insufficient brightness, this is a sign of failure of an individual crystal or an entire group. The nature of the malfunction is precisely determined by the design of the 220 V LED lamp. How to repair devices that have similar problems? First of all, you need to carry out diagnostics and identify specific areas of malfunction. Irretrievably damaged diodes usually have black dots on the surface. They should be dismantled, the place cleaned and new crystals installed. The problem will be that the emission spectrum of diodes may differ even with nominally similar parameters, so difficulties arise in selecting the optimally appropriate emitter.

Conclusion

The use of LED lamps justifies itself both in the industrial sphere and in everyday life. If at the dawn of this technology its advantages in the form of energy savings and long service life came to the fore, today control capabilities are increasingly valued. However, new problems also arise, also caused by the multi-component design of the 220 V LED lamp. Repair in the event of serious breakdowns requires the need full analysis product and subsequent re-soldering of conductors. At least this applies to diode replacement operations. The system also includes drivers, controllers and fuses. These electrical fittings also often fail. But these disadvantages can also be minimized by using not cheap Chinese LED components, but products from companies like Osram or Philips.

The design of a 220V LED lamp is much more complex than that of a similar incandescent lamp. Trying to maintain the usual pear-shaped shape, the engineers had to work hard. And, as it turned out, not in vain! New lighting devices practically do not heat up, consume a small amount of electricity and have become much less fragile. But what is special about an LED lamp and what is the complexity of its circuitry? Let's figure it out.

Structural diagram

Structurally, the 220V LED lamp consists of three main parts: the housing, the electronic part and the cooling system. The mains voltage is supplied through the base to the driver, where it is converted into a direct current signal necessary for lighting the LEDs. Light from emitting diodes has a wide scattering angle and therefore does not require the installation of additional lenses. A diffuser is enough. During operation, driver parts and LEDs become hot. Therefore, heat dissipation must be carefully considered in the design of the lamp. The body part of the LED lamp includes a base, a plastic shell inside which the driver is located, and a translucent cover in the form of a hemisphere, which also serves as a light diffuser. IN expensive models lamps, most of the body is occupied by a ribbed radiator made of aluminum or special heat-conducting plastic. In budget-class light bulbs, the radiator is either completely absent or located inside, and holes are made around the circumference of the body. Cheap Chinese products with a power of up to 7 W have a solid body, without any heat dissipation.

In branded LED lamps at 220V, a printed circuit board with SMD LEDs is attached to the radiator through thermal paste for effective heat dissipation. In cheap Chinese models, this board is either simply inserted into the grooves of the case, or attached with self-tapping screws to a metal plate for cooling the crystals. The efficiency of such cooling is extremely low, since the plate has a small area, and Chinese manufacturers, as a rule, forget to apply thermal paste.
The radiation is output through a diffuser, usually made of matte plastic. And in cheap 220V LED lamps, such a housing still reliably hides the shortcomings of the Chinese assembly from the prying eyes of the consumer. The diffuser is attached to the base either with sealant or a threaded connection.

Electrical diagram

Regarding the electrical part between different 220V LED lamps price categories there are also many differences. You can verify this immediately after dismantling the diffuser. It is enough to consider the quality of soldering of SMD elements and connecting wires.

Inexpensive Chinese lamp 220V

Bulbs costing $2-3 do not have any symmetry on the board with LEDs, which indicates hand soldering, and the wires were selected with the smallest possible cross-section. Instead of a reliable driver, they contain simple circuit transformerless power supply with capacitors and rectifier. The network voltage is first reduced by a non-polar metal film capacitor, rectified, and then smoothed and increased to the desired level. The load current is limited by a conventional SMD resistor, which is located on printed circuit board with LEDs.
When diagnosing and repairing LED lamps of this type, it is important to follow safety precautions, because all elements electrical circuit are potentially under high voltage. By carelessly touching the live part of the circuit with your finger, you can get electric shock, and a slipped multimeter probe can short-circuit the wires with unpleasant consequences.

Branded LED lamp

Branded LED products are distinguished not only by their pleasant appearance, but also by their quality element base. The driver itself has a more complex structure and is often assembled in one of two ways. The first involves the presence of a pulse transformer, a pulse voltage converter with subsequent stabilization of the load current.

In the second case, they do without a transformer, and the main functional load falls on a special microcircuit - the heart of the driver. Its versatility lies in the fact that it stabilizes the input voltage, supports the output current at a given frequency (PFM) or pulse width (PWM), allows dimming, and has a negative feedback system. feedback. An example would be CPC9909.
The LEDs in a 220V lamp with a current driver are reliably protected from voltage surges and network interference, the current through them corresponds to the nominal rating value, and the radiator provides high-quality heat dissipation. Such light bulbs will last much longer than their cheap Chinese counterparts, thereby proving the advantage of LEDs in practice.

How to disassemble LED lamp MR-16

To identify the cause of the breakdown, it is necessary to disassemble the lamp body. This is done without much effort.

As you can see in the photo, a ribbed surface is visible on the body. It is designed for better heat dissipation. We insert a screwdriver into one of the ribs and try to lift the glass.

It worked. You can see the printed circuit board, it is glued to the case. Prying it with a screwdriver, it separates.

Repair of LED light bulb MR-16

One of the first to be disassembled was the lamp, the LED inside of which had burned out. The printed circuit board, which is made of fiberglass, burned through.

This lamp will be suitable as a “donor”; the necessary spare parts will be taken from it to repair other lamps. The LEDs on the remaining 9 lamps also burned out. Since the driver is intact, the cause of the breakdown is the LEDs.

Electrical circuit of the LED lamp MR-16

To reduce lamp repair time, you need to create it electrical diagram. It's pretty simple.

Attention! The circuit is connected to the network phase by galvanic means. It is prohibited to use it to power any devices.

How does the scheme work? A voltage of 220 V is supplied to the diode bridge VD1-VD4 through capacitor C1. It is then supplied to the LEDs HL1-HL27, which are connected in series in the circuit. The number of LEDs can be about 80 pieces. Capacitor C2 (the larger the capacitance, the better) is a smoother for rectified voltage ripples. It eliminates the flicker of light having a frequency of 100 Hz. R1 was set to discharge C1. This is necessary in order to prevent electric shock when replacing the lamp. C2 is protected from breakdown of R2 in the event of an open circuit. R1, R2 do not accept work as such in the circuit.

C1 - red, C2 - black, diode bridge - housing with four legs.

Classic driver circuit for LED lamps up to 5 W

The electrical circuit of the lamps does not have protection elements. You will need a 100-200 ohm resistor, or better yet two. One will be installed in the connection circuit, the second will serve as protection against current surges.

Above is a circuit with protective resistors. R3 protects the LEDs and C2 capacitor, R2 in turn protects the diode bridge. This driver is perfect for lamps whose power is less than 5 W. It will easily power a lamp with 80 SMD3528 LEDs. If you need to reduce or increase the current, manipulate capacitor C1. To eliminate flickering, increase capacity C2.

The efficiency of such a driver is less than 50%. For example, the MR-16-2835-F27 lamp requires a 6.1 kOhm resistor with a power of 4 W. Then the driver will consume power that exceeds the power consumption of the LEDs. Because of large discharge thermal energy cannot be placed into a small lamp body. In this case, you can separately make a housing for this driver.

It should be remembered that the efficiency of the lamp directly depends on the number of LEDs.

Finding faulty LEDs

After the protective glass has been removed, you can inspect the LEDs. If the slightest black speck is detected on the surface of the LED, it has failed. Inspect the soldering areas and check the quality of the leads. 4 poorly soldered LEDs were found in one of the lamps

LEDs with black dots were marked with a cross. Upon external inspection, the LEDs may be intact. Therefore, you need to call them with a tester. To check, you will need a voltage of a little more than 3 V. A battery, battery, or power supply will do. A current-limiting resistor with a nominal value of 1 kOhm is connected in series behind the power source.

We touch the LED with the probes. In one direction the resistance should be small (the LED can glow), in the other it should be equal to tens of megaohms.

During the test, the lamp must be secured. A bank can come to the rescue.

You can check the LED without special instruments if the device driver is intact. Voltage is applied to the lamp base, the LED leads are short-circuited with tweezers or a piece of wire.

If all LEDs are visible, the shorted one is faulty. But this method is suitable if 1 LED in the circuit fails.

If a failure of several LEDs is detected in the circuit, the lamp will light. Only its luminous flux will decrease. Just short-circuit the pads to which the LEDs were soldered.

Other malfunctions of LED lamps

If upon inspection it turns out that the LEDs are working properly, then the problem is in the driver or the soldering area.

Cold soldering of the conductor was detected in this lamp. Soot, which appeared due to poor soldering, settled on the board tracks. To remove the soot, you needed a cloth moistened with alcohol. The wire was desoldered, tinned and soldered. This lamp worked.

Of all the lamps, one had a driver failure. The diode bridge was replaced by 4 “IN4007” diodes, which are rated for a current of 1 A and reverse voltage 1000 V.

Soldering SMD LEDs

To replace a faulty LED, you need to unsolder it without damaging the printed conductors. This can be done with difficulty with a regular soldering iron; it is better to put a tip made of copper wire on the soldering iron.

When soldering the LED, you must pay attention to the polarity. Install the LED at the soldering site, take a 10-15 W soldering iron and heat its ends.

If the LED is burnt and the board is charred, this area should be cleaned. Because it is a conductor. If the pad is delaminated, solder the mono LED to the “neighbors”. This is done if the paths lead exactly to them. Just take a piece of wire, fold it two or three times and solder it.

Analysis of the causes of failure of LED lamps MR-16-2835-F27

According to the table, we can conclude that lamp failures often occur due to failure of LEDs. The reason for this is the lack of protection in the circuit. Although there is space for a varistor on the board.

Repair of LED lamp series “LL-CORN” (corn lamp) E27 4.6 W 36x5050SMD

The technology for repairing a corn lamp differs from the repair of the lamp shown above.

Repairing such a lamp is simple, since the LEDs are located on the body. And dialing does not require any extra steps. This lamp was disassembled purely out of interest.

The technique for checking “corn” is no different from that described above. Only in the body of these lamps there are 3 LEDs. When ringing, all 3 should light up.

If one of the LEDs is found to be broken, short-circuit it or solder in a new one. This will not affect the life of the lamp. The lamp driver does not have an isolating transformer. Therefore, any touching of the LED tracks is unacceptable.

If the LEDs are intact, the problem is in the driver. In order to inspect it, it is necessary to disassemble the body.

To get to the driver, you need to remove the bezel. Pry it with a screwdriver at the weakest point, it should come off.

The driver has the same circuit as our first lamp with the difference that C1-1µF, C2- 4.7 µF. The wires are long, so the driver can be pulled out without effort. After work on replacing the LED, the rim was installed with Moment glue.

Repair of LED lamp “LL-CORN” (corn lamp) E27 12 W 80x5050SMD

Repairing a 12 W lamp is done according to the same scheme. No burnt-out LEDs were found on the case, so I had to open the case to inspect the driver.

There are problems with this lamp. The driver wires were too short and the base had to be removed.

The base is made of aluminum. It was attached to the body using a core. Therefore, it was necessary to drill out the fastening points with a drill whose diameter is 1.5 mm. Next, the base was pryed off with a knife and removed. The wires inside had to be cut.

Inside there were 2 identical drivers, each of which powered 43 diodes.

The driver is wrapped in a heat-shrinkable tube, which had to be cut.

After troubleshooting, the same tube is placed on the driver and crimped with a plastic tie.

The driver circuit includes protection. C1 protects against pulse surges, R2, R3 against current surges. During the testing work, R2 breaks were noticed. Most likely, a voltage exceeding the norm was applied to the lamp. There was no 10 ohm resistor, so a 5.1 ohm resistor was soldered in. The lamp lit up. Next we needed to connect the driver to the socket.

First of all, the short wires were replaced with longer ones. The drivers were connected by supply voltage. To attach the wires to the threaded part of the base, you need to clamp them between the plastic housing and the base.

How to connect to the central contact? Aluminum cannot be soldered, so the wire was soldered to a brass plate in which a hole was drilled for M 2.5. A similar hole was drilled in the contact. The whole thing was screwed together. Next, the base was put on and secured to the lamp body with a cap. The lamp was operational.

Repair of LED lamp series “LLB” E27 6 W 128-1

The design of the lamp is ideal for repairs. The housing is easy to disassemble.

You should hold the base with one hand and turn the protective shade counterclockwise with the other.

Under the body there are five rectangular boards on which LEDs are soldered. The rectangle is soldered to a round board on which the driver circuit is located.

To gain access to the LED terminals, you need to remove one of the covers. To make work easier, it is better to remove the board located at the driver voltage supply points. The photo shows that this wall is parallel to the capacitor body and is separated from it at the maximum distance.

To remove the board, you need to warm up the soldering areas with a soldering iron. Then, to remove it, we heat up the soldering on the round board and it disconnects.

Access to check damage is open. The driver is designed according to a simple design. Checking its rectifier diodes, as well as all the LEDs (there are 128 of them in this lamp) did not show a problem.

When I inspected the solder joints, I discovered that they were missing at some points. These places were soldered; in addition, I connected the printed circuit board tracks in the corners.

When you look at the light, these paths are clearly visible and you can easily determine which path is which.

Before assembling the lamp, it was necessary to test it. To do this, a jumper was installed on the board, and the soldered part of the lamp was connected to the power source with two temporary wires.

The lamp lit up. All that remains is to solder the board in its original place and assemble the lamp.

Repair of LED lamp series “LLB” LR-EW5N-5

On appearance The lamp is made with high quality. The body is aluminum and the design is beautiful.

The lamp is assembled securely. Therefore, to disassemble it, you need to remove the protective glass. To do this, insert the end of a screwdriver between the radiator. The glass is fixed here without glue, with a collar. You need to rest the screwdriver on the end of the radiator and lift the glass up, using the screwdriver as a lever.

The tester did not show any failure of the LEDs. So it's all about the driver. To get to it, you need to unscrew 4 screws.

But failure overtook me. Behind the board there was a radiator plane. It is lubricated with a paste that conducts heat. I had to collect everything I had unwound. I decided to disassemble the lamp from the base side.

In order to remove the base, I had to drill out the core points. But he didn't act. As it turned out, it was fastened to plastic with a threaded connection.

The radiator had to be separated from the plastic adapter. To do this, I cut with a hacksaw in the place where the plastic was attached to the radiator. Then, by turning the screwdriver, the parts were separated from one another.

The pins were unsoldered from the LED board, which made it possible to work with the driver. Its circuit was more complex compared to other drivers. Upon inspection, a swollen capacitor 400 V 4.7 µF was found. It has been replaced.

The Schottky diode "D4" type SS110 was damaged. It's at the bottom left of the photo. It was replaced by the analogue "10 BQ100", which has 1 A and 100 V. The light bulb lit up.

Repair of LED lamp series “LLB” LR-EW5N-3

The lamp is similar to the "LLB" LR-EW5N-5, but its design has been changed.

The protective glass is secured with a ring. If you pick up the junction of the ring and the glass, it can be easily removed.

The printed circuit board is made of aluminum. There are nine crystals on it LED light emitting diodes quantity 3 pieces. The board is secured with 3 screws to the heatsink. The check did not reveal any problems with the LEDs. So it's a driver issue. Experience in repairing a similar lamp has shown that it is better to immediately unsolder the wires that come from the driver. The lamp was disassembled from the base side.

The ring connecting the base and the radiator was removed with great effort. At the same time, a piece broke off. And all because it was screwed with 3 screws. The driver has been removed.

The screws are located under the driver; you can reach them with a Phillips screwdriver.

This driver is based on a transformer circuit. The check showed the serviceability of all parts except the microcircuit. I didn't find any information about her. The lamp was set aside as a donor.

Repair of LED lamp series "LLC" E14 3W1 M1

This lamp is similar to an incandescent lamp. The first thing you notice is the wide metal ring.

I started disassembling the lamp. The first step was to remove the lampshade. As it turned out, it was placed on the base with an elastic compound. After I took it off, I realized that it was in vain.

The lamp contained 1 LED, the power of which was 3.3 W. It could be checked from the base side.

LED light sources are quickly gaining popularity and replacing uneconomical incandescent lamps and dangerous fluorescent analogues. They use energy efficiently, last a long time, and some of them can be repaired after failure.

To properly replace or repair a broken element, you will need an LED lamp circuit and knowledge of design features.

A close acquaintance with the design of an LED lamp may be required only in one case - if it is necessary to repair or improve the light source.

Home craftsmen, having a set of elements on hand, can independently assemble an LED lamp, but a beginner cannot do this. But, having studied the circuit and having basic skills in working with electronics, he can replace broken parts and restore the functionality of the device.

Considering that LED devices have become the basis of lighting systems for modern apartments, the ability to understand the structure of lamps and repair them can save a significant part of the family budget

Does it make sense to repair an LED lamp? Undoubtedly. Unlike analogues with incandescent filaments for 10 rubles apiece, LED devices are expensive.

Let’s assume that a GAUSS “pear” costs about 80 rubles, and a better alternative OSRAM costs 120 rubles. Replacing a capacitor, resistor or diode will cost less, and the life of the lamp can be extended by timely replacement.

There are many modifications of LED lamps: candles, pears, balls, spotlights, capsules, strips, etc. They differ in shape, size and design. To clearly see the difference from an incandescent lamp, consider the common pear-shaped model.

Instead of a glass bulb there is a matte diffuser, the filament is replaced by “long-playing” diodes on the board, excess heat is removed by a radiator, and voltage stability is ensured by the driver

If you look away from the usual shape, you can notice only one familiar element - the base. The size range of socles remains the same, so they fit traditional sockets and do not require changing the electrical system.

But that's where the similarities end: internal structure LED devices are much more complex than incandescent lamps.

LED lamps are not designed to operate directly from a 220 V network, so a driver is located inside the device, which is both a power supply and control unit. It consists of many small elements, the main task of which is to rectify the current and reduce the voltage.

Circuits with capacitors to reduce voltage

To create the optimal voltage for operation of a device using diodes, the driver is assembled based on a circuit with a capacitor or a step-down transformer. The first option is cheaper, the second is used to equip high-power lamps.

There is a third type - inverter circuits, which are implemented either for the assembly of dimmable lamps, or for devices with a large number diodes.

Let's consider an example involving a capacitor, since such circuits are common in household lamps.

Elementary circuit of an LED lamp driver. The main elements that dampen the voltage are capacitors (C2, C3), but resistor R1 also performs the same function

Capacitor C1 protects against power line interference, and C4 smoothes out ripples. At the moment the current is supplied, two resistors - R2 and R3 - limit it and at the same time protect it from short circuit, and element VD1 converts alternating voltage.

When the current supply stops, the capacitor is discharged using resistor R4. By the way, R2, R3 and R4 are not used by all manufacturers of LED products.

Disadvantages of a circuit with capacitors:

The diodes may burn out, since the current supply is not stable. The load voltage is completely dependent on the supply voltage.
There is no galvanic isolation, so there is a risk of electric shock. It is not recommended to touch current-carrying elements when disassembling lamps, as they are under phase.
It is almost impossible to achieve high glow currents, because this will require an increase in capacitor capacities.

However, there are also many advantages, which is why capacitors remain popular. The advantages are ease of assembly, wide range of output voltages and low cost.

Feel free to experiment with self-production Moreover, some of the parts can be found in old receivers or televisions.

Sample Switching Driver - Model CPC9909

Unlike a linear driver with a capacitor, a pulsed one effectively protects LEDs from voltage surges and network interference.

Example pulse device The popular electronic model CPC9909 is used. The efficiency of its use reaches 98% - an indicator at which we can really talk about energy saving and savings.

The CPC9909 chip, developed by Clare, is often used for self-assembly LED lamps, including increased power. The controller is housed in a compact plastic housing

The device can be powered directly from high voltage– up to 550 V, since the driver is equipped with a built-in stabilizer. Thanks to the same stabilizer, the circuit has become simpler and the cost is lower.

LED driver circuit based on the CPC9909 chip. Advantages of the circuit: ability to operate in the temperature range from -55 °C to +85 °C and powered by alternating voltage current

The microcircuit is successfully used for the development of electrical networks for emergency and backup lighting, since it is suitable for boost converter circuits.

At home, lamps powered by batteries or drivers with a power not exceeding 25 V are most often assembled based on the CPC9909.

Types of dimmable drivers

Adjusting the brightness of lighting fixtures allows you to set the desired level of lighting in the room. This is convenient when creating separate zones, reducing the brightness of light during the day, or for highlighting interior items.

With the help of a dimmer, the use of electricity becomes more rational, and the service life of the electrical appliance increases.

Sample of a retro style lamp with a dimmer. In appearance, the tabletop lighting device resembles a kerosene lamp and has a brightness control knob on the side.

There are two types of dimmable drivers, each with their own advantages. The first ones work with PWM control.

They are installed between the lamp and the power supply. Energy is supplied in the form of pulses of different durations. An example of using a driver with PWM regulation is a creeping line.

Testing a 40W dimmable driver. It is designed for office lamps, as well as devices for car parks and public buildings where energy saving mode is required

Dimmable drivers of the second type act directly on the power source and are used for devices with stabilized current.

When regulating the current, a change in the shade of the glow may occur: diodes white when the current decreases, they begin to emit slightly yellow light, and when zoomed in – blue.

Brief review and testing of LED lamps

Although the principles of constructing driver circuits for various lighting devices are similar, there are differences between them both in the sequence of connecting the elements and in their choice.

Review of popular LED models

Let's look at the circuits of 4 lamps that are sold in the public domain. If desired, you can repair them yourself.

Image gallery

If you have experience working with controllers, you can replace the elements of the circuit, resolder it, and slightly improve it.

However, meticulous work and efforts to find elements are not always justified - it is easier to buy a new lighting fixture.

Option #1 – LED lamp BBK P653F

The BBK brand has two very similar modifications: the P653F lamp differs from the P654F model only in the design of the emitting unit. Accordingly, both the driver circuit and the design of the device as a whole in the second model are built according to the design principles of the first.

The driver circuit is standard, but complicated by the unusual location of the key and the embedded inductance. The fuse could be installed near the diode bridge, but it is missing

It's easy to spot flaws in the design. For example, the installation location of the controller: partly in the radiator, if there is no insulation, partly in the base. The assembly on the SM7525 chip produces an output of 49.3 V.

Option #2 – Ecola 7w LED lamp

The radiator is made of aluminum, the base is made of heat-resistant gray polymer. On a half-millimeter thick printed circuit board there are 14 diodes connected in series.

Between the heatsink and the board there is a layer of heat-conducting paste. The base is fixed with self-tapping screws.

The controller circuit is simple, implemented on a compact board. The LEDs heat the base board to +55 ºС. There is practically no pulsation, radio interference is also excluded

The board is completely placed inside the base and connected with shortened wires. The occurrence of short circuits is impossible, since there is plastic around - insulating material. The result at the controller output is 81 V.

Option #3 – collapsible lamp Ecola 6w GU5.3

Thanks to the collapsible design, you can independently carry out repairs or improve the device driver.

However, the unsightly appearance and design of the device spoils the impression. An oversized radiator increases the weight, so additional fixation is recommended when attaching the lamp to the socket.

The board has compact dimensions and a well-thought-out arrangement of elements, for the fastening of which both planes are used. The presence of ripples is explained by the absence of a filter capacitor, which should be at the output

The disadvantage of the circuit is the presence of noticeable pulsations of the light flux and a high degree of radio interference, which will certainly affect the service life. The controller is based on a BP3122 microcircuit, the output value is 9.6 V.

Option #4 – Jazzway 7.5w GU10 lamp

The external elements of the lamp are easily detached, so you can get to the controller quickly enough by unscrewing two pairs of screws. The protective glass is held in place by latches. The board contains 17 diodes with serial communication.

However, the controller itself, located in the base, is generously filled with compound, and the wires are pressed into the terminals. To free them, you need to use a drill or use desoldering.

The disadvantage of the circuit is that the function of the current limiter is performed by a conventional capacitor. When the lamp is turned on, current surges occur, resulting in either burnout of the LEDs or failure of the LED bridge

There is no radio interference observed - and all thanks to the absence pulse controller, but at a frequency of 100 Hz, noticeable pulsations of light are observed, reaching up to 80% of the maximum value.

The result of the controller is 100 V output, but according to the general assessment, the lamp is more likely to be a weak device. Its cost is clearly overestimated and is equal to the cost of brands that are distinguished by stable product quality.

Conclusions and useful video on the topic

You can learn how drivers for LEDs are designed, what their features and functions are, from the videos below.

Analysis of the MR-16 LED lamp circuit:

Driver circuit for self-assembly of lamps with power up to 15W:

What the FT833A driver looks and does:

Homemade from scrap elements:

Nowadays you can purchase kits and individual elements for assembling lighting fixtures of various power. If desired, you can repair a failed LED lamp or modify a new one to obtain best result. When purchasing, we recommend that you carefully check the characteristics and suitability of the parts.

LED lamps have moved from luxury items to household appliances. Currently, many companies produce such light sources, since their manufacture does not require complex equipment, and the assembly scheme is simple. Now everyone can buy a miracle lighting source, but what to do if it suddenly stops working. It’s good if there is a warranty, but what if it ended or didn’t exist at all? Is it possible to repair LED lamps with your own hands? Let’s try to figure it out in today’s review.

Light sources LED type differ in power parameters and variety of configurations

Before deciding how to disassemble an LED lamp, you need to understand its structure. The design of this lighting source is not complicated: a light filter, a power board and a housing with a base.

Cheap products often use capacitors to limit voltage and current. The light bulb contains 50-60 LEDs, which represent series circuit. They form a light-emitting element.

The operating principle of the products is similar to the functioning semiconductor diodes. In this case, the current moves only directly from the anode to the cathode. What contributes to the emergence of light flows in LEDs. The parts have little power, so the lamps are produced with many LEDs. To remove the unpleasant sensations from the produced rays, a phosphor is used, which eliminates this drawback. The device eliminates heating from spotlights, since luminous fluxes decrease with heat loss.

The driver in the design is used to supply voltage to the diode groups. They are used as a converter. Diode parts are small-sized semiconductors. The voltage is transferred to a special transformer, where the operating parameters are slightly slowed down. The output is formed D.C., which allows you to turn on the diodes. Installing an additional capacitor helps prevent voltage ripple.

LED lamps come in different types. They differ in the features of the device, as well as in the number of semiconductor parts.

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We’ll talk about this in more detail in the article to help you reduce costs when purchasing and during operation, and solve other practical problems.

Reasons for repairing LED lamps: device, electrical circuits

Before you start repairing LED lamps with your own hands, it is important to find out the reasons for their failure. The declared service life of lamps may not coincide with the actual lifespan. This is due to the crystals poor quality.

There are the following reasons for malfunctions of lighting devices:

Voltage drops do not have such a strong effect on the operation of electrical parts; noticeable fluctuations in voltage readings can cause a malfunction;
unsuitable lamp. If the wrong lamp is selected, the light source may overheat.
light-emitting elements of poor quality contribute to the rapid failure of products;
incorrect installation lighting systems provides negative impact for electrical wiring;
strong vibrations and impacts may cause damage to such equipment.

So you don't have to do any repairs LED light bulb with your own hands, you need to minimize the impact of the listed factors on the lamp.

Pay attention! If there are no visually detectable deformations, then you need to look for the cause of the breakdown using special devices: a multimeter and a tester.

Frequent problems arising with ice devices

It is often necessary to repair LED lamps yourself if there are problems with the capacitor. To carry out the test, it will have to be removed from the board. You can measure the element voltage with a multimeter. The same device checks the operating condition of the diodes.

In some cases, LED elements blink. This happens if the current-limiting capacitor is faulty. The cause of the breakdown may be a burnt out emitter. The malfunction cannot be seen in all LEDs, so you will have to check every detail. A tester is used to find the problematic diode.

When making renovations, you can experiment with LED elements. For example, choose warm or cold light temperatures. Some devices do not have a smoothing capacitor and a rectifier. They can be installed using a soldering iron.

Advice! If only one LED burns out, you can close its contacts.

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How to repair an LED lamp with your own hands

If you are wondering how to repair a 220v LED lamp, then get acquainted with the standard repair schemes. The most common cause of failure is capacitor failure. A multimeter is used to check this part. If the capacitor burns out, it is replaced with a new one. Another common lamp malfunction is driver problems. When replacing this part, it is important to choose the appropriate option.

Current limiting resistors don't break often, but it does happen. You can check the malfunction using a multimeter in dial mode. If the deviation of the indicator is more than 20%, then the device is faulty.

LEDs often need to be replaced. They should be checked only after it is clear that everything is in order with the power source. To replace these parts you will need a soldering iron. All faulty elements are soldered off.

The cause of flickering of LED lighting sources is a poor-quality capacitor. To eliminate such a malfunction, it is worth purchasing a more powerful mechanism.

You can try to repair ice lamps LL-corn (corn lamps) with your own hands.

Image	Stages of work
	If it is impossible to find the burnt-out LEDs on the case, then it is dismantled.
	Since the wires are short, the base is removed.
	To remove the base, the mounting points are drilled with a drill with a diameter of 1.5. Then the base is removed using a knife.
	Inside are drivers that power 43 LEDs. The heat shrink tube on the driver is cut off.
	After repair, the tube is put back on and pressed with a plastic tie.
	The breakdown occurred as a result of high voltage. The driver is connected to the socket.

Before any repair, be sure to check the presence of voltage. This turns on the required switch. If there is no voltage, the electrical wiring is checked and the fault is eliminated.

It is important to check the functionality of the light bulb, as well as the integrity of the fuses. You can ring not only integrity, but also the possible presence of a short circuit. The power supply and LEDs are also checked. LEDs can be tested using a battery. To do this, voltage is supplied to each LED through a resistor.

If the lamp burns out more LED elements, then you need to unsolder all the old ones, and then back side solder the working elements.

LED lamp repair (video)

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