What LEDs are in 220 lamps? The operating principle of the driver in an LED lamp. Step-by-step instructions for making an LED lamp with a homemade driver

The advent of LED or LED lamps contributed to the beginning of a new stage in the lighting industry. More recently, such lighting fixtures were extremely rare, but now there is a huge assortment of different LED lamps put everything out large stores. The LED, unlike a conventional incandescent lamp, has its own startup circuit.

It is installed in the light bulb itself, between the imitation bulb and the socket. Therefore, this place is made opaque. Getting to the board with diodes is not that difficult, but some effort will be required for disassembly. Although experience shows that most manufacturers use similar models of starting devices for this, small differences still remain.

Friends, I welcome everyone to the “Electrician in the House” website. Today I want to give you an overview of the internals LED lamps, which I ordered on Aliexpress. The lamp consists of 72 diodes. It uses SMD LEDs, also known as Surface Mounting Device. Let's start disassembling it, I think you will also be very interested.

Operating principle of LED lamp

Manufactured 220V LED bulbs may differ from each other external design, but the principle internal structure persists for all models. Light emission in lamps is carried out by LEDs, the number and size of crystals of which can vary depending on the power and cooling capabilities. Their color spectrum is determined by the substance included in the structure of each crystal.

To get to the starting driver, you need to carefully remove the protective “skirt” of the lamp. A printed circuit board or mounting assembly of interconnected radio elements will open under it. Located at the driver input diode bridge, connected to the electrical base of the lamp in contact with the socket. Thanks to it, the alternating supply voltage is rectified into constant voltage, supplied to the board and through it supplied to the LEDs.

To better dissipate the emitted flux and protect the crystals from touching, as well as to avoid their contact with foreign objects, a diffuser is installed outside protective glass(transparent plastic flask). Therefore, in their appearance they are very reminiscent of traditional light sources.

To screw the light bulb into the socket, their bases are made standard sizes E14, E27, E40, etc. This allows you to use LED lamps in home network without resorting to any changes in the electrical wiring.

Design and purpose of lamp parts

Each LED lamp consists of the following parts:

#1 . Diffuser - a special hemisphere that increases the angle and evenly scatters the directed beam of LED radiation. In most cases, the element is made from transparent and translucent plastics or frosted polycarbonate. Due to this, the products do not break when dropped. The element is absent only in analogues of fluorescent lamps; there it is replaced by a special reflector. In devices with LEDs, the heating of the hemisphere is insignificant and several times less than in conventional filamentous electric lamps.

#2 . LED chips– the main components of new generation lamps. They are installed either one at a time or in dozens. Their number depends on design features product, its size, power and the presence of devices for heat removal. U good producers It is not practiced to skimp on quality LED matrices, since they determine all the operating parameters of the emitter and the duration of its operation. However, in the world such companies can be counted on one hand. The diodes in the matrices are interconnected, and if one fails, the entire lamp fails.

#3 . Printed circuit board. In their manufacture, anodized aluminum alloys are used, which can effectively remove heat to the radiator, which will create optimal temperature for uninterrupted operation of the chips.

#4 . A radiator that removes heat from printed circuit board with recessed LEDs. For casting radiators, aluminum and its alloys are also chosen, as well as special forms with a large number of individual plates to help increase the heat dissipation area.

#5 . Capacitor, cleaning voltage ripple, supplied to the LED crystals from the driver board.

#6 . Driver that smoothes, reduces and stabilizes the input voltage electrical network. Not a single LED matrix can do without this miniature printed circuit board. There are external and built-in drivers. Majority modern lamps equipped with built-in devices that are mounted directly in their housing.

#7 . Polymer base, resting closely against the base part, protecting the housing from electrical breakdowns, and those changing light bulbs from accidental electric shock.

#8 . Base providing connection to the cartridges. Typically, nickel-plated brass is used in its manufacture. This guarantees good contact and long-term corrosion protection.

Also a significant difference LED devices What changed from their conventional prototypes was the location of the maximum heating zone. For other types of emitters, heat spreads from the outside of the surface. LED crystals heat up their PCB with inside. Therefore, they require timely removal of heat from inside the lamp, and this is structurally solved by installing cooling radiators.

Design of a corn lamp

For some reason, everyone calls the lamp that we are going to disassemble today “corn”. Although looking at the appearance there really is a resemblance. I ordered a whole set of these lighting lamps for a soft box. For those who haven't seen it yet, there is a video on the YouTube channel.

External provides open access to the diodes and in case of failure, you can easily test them with a multimeter and determine the faulty diode.

The lamp consists of ten side plates with six LEDs on each plate. Plus, 12 more diodes are soldered on the top cover. A total of 72 diodes are obtained.

Let's start disassembling this miracle to quickly see the insides. Before that, you need to carefully examine the body and understand which parts are connected to each other.

On the top cover you can see parts that fit together; the cover has grooves. That's what we'll be filming. To do this, take a thin screwdriver or knife and carefully pry the lid evenly around the entire perimeter.

As you can see in the photo there is practically nothing inside. The driver is attached to the wall with double-sided tape. The side plates can be easily pulled out of the grooves. There are a lot of connecting wires around.

In the depths you can see the wires through which the power supply voltage 220 Volt from the base to the driver input. There are two wires coming out of the driver (red and white). LEDs are connected to them.

I decided to measure the voltage at the driver output. Multimeter shows voltage 77 volts (direct current). Connection diagram for all diodes performed parallel-serial. A group of three diodes connected in parallel is connected in series with another group, and so on. In total there are 24 “links” of “three diodes”.

Here is a simple device for a 220 Volt LED lamp of the “corn” type.

I didn't like the fact that this lamp does not have a radiator. And as you know, friends, the main problem with LEDs is heating and heat dissipation. There are no metal objects in it at all, with the exception of the circuit boards on which the diodes themselves are soldered; they are made of aluminum. The case is made of ceramic, there are four ventilation holes near the base.

I don't know if this is good or bad. Maybe you can tell me, friends, write in the comments.

We disassemble the LED lamp “Housekeeper”

The next LED lamp that I want to disassemble and show you its structure is the “Housekeeper”, with a power of 7 W. She has been serving me faithfully for two years now. Technical characteristics are presented in the photo.

Like the previous lamp, the base size is E27. The base itself is attached to the body with special in-depth grooves. It is impossible to remove it without drilling or other damage.

The lamp body is made of aluminum and has structural form resembling a basket. There are ribs on the sides for air circulation and additional heat removal.

This lamp has a hemispherical diffuser made of matte plastic. Unlike the previous version, where everything is cowardly and held together, here everything is assembled very well, in fact - one monolithic structure.

How to disassemble an LED lamp of this type? Here the insides are hidden behind the diffuser. We take a screwdriver with a thin tip and pry off the flask.

An aluminum plate with SMD 5730 diodes is fixed in the center on three bolts. There are 14 diodes. In my opinion, all the LEDs are connected in series. I can’t say for sure, since the connecting tracks on the board are invisible. If one of them fails, the lamp will stop working.

Thermal paste is applied at the contact point between the board and the metal case ( white, the structure resembles ordinary silicone sealant).

By unscrewing three screws and lifting the board, you can see the main thing - the driver.

The driver is compactly located in the central tube.

Let's measure what voltage the driver produces. The multimeter shows voltage within 44 Volts.

The design of a 220V LED lamp is much more complex than that of a similar incandescent lamp. Trying to maintain the familiar 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 circuit 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 220V LED lamps, 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 thermal paste must be applied Chinese manufacturers are usually forgotten.
The radiation is output through a diffuser, usually made of matte plastic. And in cheap 220V LED lamps such a housing still reliably hides shortcomings 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 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 a simple transformerless power supply circuit with capacitors and a rectifier. The network voltage is first reduced by a non-polar metal film capacitor, rectified, and then smoothed and increased to the desired level. Load current limited regular SMD resistor, which is located on the 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 provides for the presence pulse transformer, pulse converter voltage 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.

About filament lamps

By appearance A filament lamp is similar to an incandescent lamp. The design of filament lamps differs from LED lamps in that they do not use a board with LEDs as light emitters, but a sealed glass flask filled with gas, in which one or more filament rods are placed. The driver is located in the base.

The filament rod is a glass or sapphire tube with a diameter of about 2 mm and a length of about 30 mm, on which 28 miniature LEDs coated in series with a phosphor are attached and connected. One filament consumes about 1 W of power. My operating experience shows that filament lamps are much more reliable than those made on the basis of SMD LEDs. I believe that over time they will supplant all others artificial sources Sveta.

Examples of LED lamp repairs

Attention, the electrical circuits of the LED lamp drivers are galvanically connected to the phase of the electrical network and therefore extreme care should be taken. Touching an unprotected part of a person’s body to exposed parts of a circuit connected to an electrical network can cause serious damage to health, including cardiac arrest.

LED lamp repair
ASD LED-A60, 11 W on SM2082 chip

Currently, powerful LED light bulbs have appeared, the drivers of which are assembled on SM2082 type chips. One of them worked for less than a year and ended up being repaired. The light went out randomly and came back on again. When you tapped it, it responded with light or extinguishing. It became obvious that the problem was poor contact.

To get to the electronic part of the lamp, you need to use a knife to pick up the diffuser glass at the point of contact with the body. Sometimes it is difficult to separate the glass, since when it is seated, silicone is applied to the fixing ring.

After removing the light-scattering glass, access to the LEDs and the SM2082 current generator microcircuit became available. In this lamp, one part of the driver was mounted on an aluminum LED printed circuit board, and the second on a separate one.

An external inspection did not reveal any defective soldering or broken tracks. I had to remove the board with LEDs. To do this, the silicone was first cut off and the board was pryed off by the edge with a screwdriver blade.

To get to the driver located in the lamp body, I had to unsolder it by heating two contacts with a soldering iron at the same time and moving it to the right.

On one side of the driver circuit board, only an electrolytic capacitor with a capacity of 6.8 μF for a voltage of 400 V was installed.

WITH reverse side The driver board was equipped with a diode bridge and two series-connected resistors with a nominal value of 510 kOhm.

In order to figure out which of the boards the contact was missing, we had to connect them, observing the polarity, using two wires. After tapping the boards with the handle of a screwdriver, it became obvious that the fault lies in the board with the capacitor or in the contacts of the wires coming from the base of the LED lamp.

Since the soldering did not raise any suspicions, I first checked the reliability of the contact in the central terminal of the base. It can be easily removed if you pry it over the edge with a knife blade. But the contact was reliable. Just in case, I tinned the wire with solder.

It is difficult to remove the screw part of the base, so I decided to use a soldering iron to solder the soldering wires coming from the base. When I touched one of the soldering joints, the wire became exposed. A “cold” solder was detected. Since there was no way to get to the wire to strip it, I had to lubricate it with FIM active flux and then solder it again.

After assembly, the LED lamp consistently emitted light, despite hitting it with the handle of a screwdriver. Examination luminous flux on pulsations showed that they are significant with a frequency of 100 Hz. Such an LED lamp can only be installed in luminaires for general lighting.

Driver circuit diagram
LED lamp ASD LED-A60 on SM2082 chip

The electrical circuit of the ASD LED-A60 lamp, thanks to the use of a specialized SM2082 microcircuit in the driver to stabilize the current, turned out to be quite simple.

The driver circuit works as follows. The AC supply voltage is supplied through fuse F to the rectifier diode bridge assembled on the MB6S microassembly. Electrolytic capacitor C1 smoothes out ripples, and R1 serves to discharge it when the power is turned off.

From the positive terminal of the capacitor, the supply voltage is supplied directly to the LEDs connected in series. From the output of the last LED, the voltage is supplied to the input (pin 1) of the SM2082 microcircuit, the current in the microcircuit is stabilized and then from its output (pin 2) goes to the negative terminal of capacitor C1.

Resistor R2 sets the amount of current flowing through the HL LEDs. The amount of current is inversely proportional to its rating. If the value of the resistor is decreased, the current will increase; if the value is increased, the current will decrease. The SM2082 microcircuit allows you to adjust the current value with a resistor from 5 to 60 mA.

LED lamp repair
ASD LED-A60, 11 W, 220 V, E27

The repair included another ASD LED-A60 LED lamp, similar in appearance and with the same technical characteristics as the one repaired above.

When turned on, the lamp came on for a moment and then did not shine. This behavior of LED lamps is usually associated with a driver failure. So I immediately started disassembling the lamp.

The light-scattering glass was removed with great difficulty, since along the entire line of contact with the body it was, despite the presence of a retainer, generously lubricated with silicone. To separate the glass, I had to look for a pliable place along the entire line of contact with the body using a knife, but still there was a crack in the body.

To access the lamp driver on next step we had to remove the LED printed circuit board, which was pressed along the contour into an aluminum insert. Despite the fact that the board was aluminum and could be removed without fear of cracks, all attempts were unsuccessful. The board held tight.

It was also not possible to remove the board together with the aluminum insert, since it fit tightly to the case and was seated with the outer surface on silicone.

I decided to try removing the driver board from the base side. To do this, first, a knife was pryed out of the base and the central contact was removed. To remove the threaded part of the base, it was necessary to slightly bend its upper flange so that the core points would disengage from the base.

The driver became accessible and was freely extended to a certain position, but it was not possible to remove it completely, although the conductors from the LED board were sealed off.

The LED board had a hole in the center. I decided to try to remove the driver board by hitting its end through a metal rod threaded through this hole. The board moved a few centimeters and hit something. After further blows, the lamp body cracked along the ring and the board with the base of the base separated.

As it turned out, the board had an extension whose shoulders rested against the lamp body. It looks like the board was shaped this way to limit movement, although it would have been enough to fix it with a drop of silicone. Then the driver would be removed from either side of the lamp.

Voltage 220 V from the lamp base through a resistor - fuse FU is supplied to rectifier bridge MB6F and after it is smoothed by an electrolytic capacitor. Next, the voltage is supplied to the SIC9553 chip, which stabilizes the current. Parallel connected resistors R20 and R80 between pins 1 and 8 MS set the amount of LED supply current.

The photo shows a typical electrical circuit diagram, given by the manufacturer of the SIC9553 chip in the Chinese datasheet.

This photo shows the appearance of the LED lamp driver from the installation side of the output elements. Since space allowed, to reduce the pulsation coefficient of the light flux, the capacitor at the driver output was soldered to 6.8 μF instead of 4.7 μF.

If you have to remove the drivers from the body of this lamp model and cannot remove the LED board, you can use a jigsaw to cut the lamp body around the circumference just above the screw part of the base.

In the end, all my efforts to remove the driver turned out to be useful only for understanding the LED lamp structure. The driver turned out to be OK.

The flash of the LEDs at the moment of switching on was caused by a breakdown in the crystal of one of them as a result of a voltage surge when the driver was started, which misled me. It was necessary to ring the LEDs first.

An attempt to test the LEDs with a multimeter was unsuccessful. The LEDs did not light up. It turned out that two light-emitting crystals connected in series are installed in one case, and in order for the LED to start flowing current, it is necessary to apply a voltage of 8 V to it.

A multimeter or tester turned on in resistance measurement mode produces a voltage within 3-4 V. I had to check the LEDs using a power supply, supplying 12 V to each LED through a 1 kOhm current-limiting resistor.

There was no replacement LED available, so the pads were shorted with a drop of solder instead. This is safe for driver operation, and the power of the LED lamp will decrease by only 0.7 W, which is almost imperceptible.

After repairing the electrical part of the LED lamp, the cracked body was glued with quick-drying Moment super glue, the seams were smoothed by melting the plastic with a soldering iron and leveled with sandpaper.

Just for fun, I did some measurements and calculations. The current flowing through the LEDs was 58 mA, the voltage was 8 V. Therefore, the power supplied to one LED was 0.46 W. With 16 LEDs, the result is 7.36 W, instead of the declared 11 W. Perhaps the manufacturer has indicated the total power consumption of the lamp, taking into account losses in the driver.

The service life of the ASD LED-A60, 11 W, 220 V, E27 LED lamp declared by the manufacturer raises serious doubts in my mind. In the small volume of the plastic lamp body, with low thermal conductivity, significant power is released - 11 W. As a result, the LEDs and driver work at their maximum capacity. permissible temperature, which leads to accelerated degradation of their crystals and, as a consequence, to a sharp decrease in their time between failures.

LED lamp repair
LED smd B35 827 ERA, 7 W on BP2831A chip

An acquaintance shared with me that he bought five light bulbs like in the photo below, and after a month they all stopped working. He managed to throw away three of them, and, at my request, brought two for repairs.

The light bulb worked, but instead of bright light it emitted a flickering weak light with a frequency of several times per second. I immediately assumed that the electrolytic capacitor had swollen; usually, if it fails, the lamp begins to emit light like a strobe.

The light-scattering glass came off easily, it was not glued. It was fixed by a slot on its rim and a protrusion in the lamp body.

The driver was secured using two solders to a printed circuit board with LEDs, as in one of the lamps described above.

A typical driver circuit on the BP2831A chip taken from the datasheet is shown in the photograph. The driver board was removed and all simple radio elements were checked; they all turned out to be in good order. I had to start checking the LEDs.

LEDs in the lamp were installed unknown type with two crystals in the case and inspection did not reveal any defects. Method serial connection between the leads of each LED, I quickly identified the faulty one and replaced it with a drop of solder, as in the photo.

The light bulb worked for a week and was repaired again. Shorted the next LED. A week later I had to short-circuit another LED, and after the fourth I threw out the light bulb because I was tired of repairing it.

The reason for the failure of light bulbs of this design is obvious. LEDs overheat due to insufficient heat sink surface, and their service life is reduced to hundreds of hours.

Why is it permissible to short-circuit the terminals of burnt-out LEDs in LED lamps?

LED lamp driver, as opposed to power supply DC voltage, the output produces a stabilized current value, not voltage. Therefore, regardless of the load resistance within the specified limits, the current will always be constant and, therefore, the voltage drop across each of the LEDs will remain the same.

Therefore, as the number of series-connected LEDs in the circuit decreases, the voltage at the driver output will also decrease proportionally.

For example, if 50 LEDs are connected in series to the driver, and each of them drops a voltage of 3 V, then the voltage at the driver output is 150 V, and if you short-circuit 5 of them, the voltage will drop to 135 V, and the current will not change.

But the coefficient useful action(Efficiency) of a driver assembled according to this scheme will be low and power losses will be more than 50%. For example, for an LED light bulb MR-16-2835-F27 you will need a 6.1 kOhm resistor with a power of 4 watts. It turns out that the resistor driver will consume power exceeding the power consumption of the LEDs and place it in small body LED lamps, due to allocation more heat will be unacceptable.

But if there is no other way to repair an LED lamp and it is very necessary, then the resistor driver can be placed in a separate housing; anyway, the power consumption of such an LED lamp will be four times less than incandescent lamps. It should be noted that the more LEDs connected in series in a light bulb, the higher the efficiency will be. With 80 series-connected SMD3528 LEDs, you will need an 800 Ohm resistor with a power of only 0.5 W. The capacitance of capacitor C1 will need to be increased to 4.7 µF.

Finding faulty LEDs

After removing the protective glass, it becomes possible to check the LEDs without peeling off the printed circuit board. First of all, a careful inspection of each LED is carried out. If even the smallest black dot is detected, not to mention blackening of the entire surface of the LED, then it is definitely faulty.

When inspecting the appearance of the LEDs, you need to carefully examine the quality of the soldering of their terminals. One of the light bulbs being repaired turned out to have four LEDs that were poorly soldered.

The photo shows a light bulb that had very small black dots on its four LEDs. I immediately marked the faulty LEDs with crosses so that they were clearly visible.

Faulty LEDs may not have any changes in appearance. Therefore, it is necessary to check each LED with a multimeter or pointer tester turned on in resistance measurement mode.

There are LED lamps in which standard LEDs are installed in appearance, in the housing of which two crystals connected in series are mounted at once. For example, lamps of the ASD LED-A60 series. To test such LEDs, it is necessary to apply a voltage of more than 6 V to its terminals, and any multimeter produces no more than 4 V. Therefore, checking such LEDs can only be done by applying a voltage of more than 6 (recommended 9-12) V to them from the power source through a 1 kOhm resistor .

The LED is checked as regular diode, in one direction the resistance should be equal to tens of megaohms, and if you swap the probes (this changes the polarity of the voltage supply to the LED), then it will be small, and the LED may glow dimly.

When checking and replacing LEDs, the lamp must be fixed. For this you can use suitable size round jar.

You can check the serviceability of the LED without an additional DC source. But this verification method is possible if the light bulb driver is working properly. To do this, it is necessary to apply supply voltage to the base of the LED light bulb and short-circuit the terminals of each LED in series with each other using a wire jumper or, for example, the jaws of metal tweezers.

If suddenly all the LEDs light up, it means that the shorted one is definitely faulty. This method is suitable if only one LED in the circuit is faulty. With this method of checking, it is necessary to take into account that if the driver does not provide galvanic isolation from the electrical network, as for example in the diagrams above, then touching the LED solders with your hand is unsafe.

If one or even several LEDs turn out to be faulty and there is nothing to replace them with, then you can simply short-circuit the contact pads to which the LEDs were soldered. The light bulb will work with the same success, only the luminous flux will decrease slightly.

Other LED lamp faults

If checking the LEDs showed their serviceability, then the reason for the light bulb’s inoperability lies in the driver or in the soldering areas of the current-carrying conductors.

For example, in this light bulb a cold solder connection was found on the conductor supplying power to the printed circuit board. The soot released due to poor soldering even settled on the conductive paths of the printed circuit board. The soot was easily removed by wiping with a rag soaked in alcohol. The wire was soldered, stripped, tinned and re-soldered into the board. I was lucky with the repair of this light bulb.

Of the ten failed bulbs, only one had a faulty driver and a broken diode bridge. The driver repair consisted of replacing the diode bridge with four IN4007 diodes, designed for reverse voltage 1000 V and current 1 A.

Soldering SMD LEDs

To replace a faulty LED, it must be desoldered without damaging it. printed conductors. The LED from the donor board also needs to be desoldered for replacement without damage.

It is almost impossible to desolder SMD LEDs with a simple soldering iron without damaging their housing. But if you use a special tip for a soldering iron or put an attachment made of copper wire on a standard tip, then the problem can be easily solved.

LEDs have polarity and when replacing, you need to install it correctly on the printed circuit board. Typically, printed conductors follow the shape of the leads on the LED. Therefore, a mistake can only be made if you are inattentive. To seal an LED, it is enough to install it on a printed circuit board and heat its ends with the contact pads with a 10-15 W soldering iron.

If the LED burns out like charcoal and the printed circuit board underneath is charred, then before installing new LED It is imperative to clean this area of the printed circuit board from burning, since it is a current conductor. When cleaning, you may find that the LED solder pads are burnt or peeled off.

In this case, the LED can be installed by soldering it to adjacent LEDs if the printed traces lead to them. To do this, you can take a piece of thin wire, bend it in half or three times, depending on the distance between the LEDs, tin it and solder it to them.

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

The design of the lamp, which is popularly called a corn lamp, shown in the photo below differs from the lamp described above, therefore the repair technology is different.

The design of LED SMD lamps of this type is very convenient for repair, since there is access to test the LEDs and replace them without disassembling the lamp body. True, I still disassembled the light bulb for fun in order to study its structure.

Examination LEDs The corn lamp is no different from the technology described above, but we must take into account that the SMD5050 LED housing contains three LEDs at once, usually connected in parallel (three dark dots of the crystals are visible on the yellow circle), and when checked, all three should light up.

A faulty LED can be replaced with a new one or short-circuited with a jumper. This will not affect the reliability of the lamp, only the luminous flux will decrease slightly, imperceptibly to the eye.

The driver for this lamp is assembled using the simplest scheme, without an isolating transformer, so touching the LED terminals when the lamp is on is unacceptable. Lamps of this design must not be installed in lamps that can be reached by children.

If all the LEDs are working, it means the driver is faulty, and the lamp will have to be disassembled to get to it.

To do this, you need to remove the rim from the side opposite the base. Using a small screwdriver or a knife blade, try in a circle to find the weak spot where the rim is glued the worst. If the rim gives way, then using the tool as a lever, the rim will easily come off around the entire perimeter.

The driver was assembled according to the electrical circuit, like the MR-16 lamp, only C1 had a capacity of 1 µF, and C2 - 4.7 µF. Due to the fact that the wires going from the driver to the lamp base were long, the driver was easily removed from the lamp body. After studying its circuit diagram, the driver was inserted back into the housing, and the bezel was glued into place with transparent Moment glue. The failed LED was replaced with a working one.

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

When repairing a more powerful lamp, 12 W, there were no failed LEDs of the same design and in order to get to the drivers, we had to open the lamp using the technology described above.

This lamp gave me a surprise. The wires leading from the driver to the socket were short, and it was impossible to remove the driver from the lamp body for repair. I had to remove the base.

The lamp base was made of aluminum, cored around the circumference and held tightly. I had to drill out the mounting points with a 1.5 mm drill. After this, the base, pryed off with a knife, was easily removed.

But you can do without drilling the base if you use the edge of a knife to pry it around the circumference and slightly bend its upper edge. You should first put a mark on the base and body so that the base can be conveniently installed in place. To securely fasten the base after repairing the lamp, it will be enough to put it on the lamp body in such a way that the punched points on the base fall into the old places. Next, press these points with a sharp object.

Two wires were connected to the thread with a clamp, and the other two were pressed into the central contact of the base. I had to cut these wires.

As expected, there were two identical drivers, feeding 43 diodes each. They were covered with heat shrink tubing and taped together. In order for the driver to be placed back into the tube, I usually carefully cut it along the printed circuit board from the side where the parts are installed.

After repair, the driver is wrapped in a tube, which is fixed with a plastic tie or wrapped with several turns of thread.

In the electrical circuit of the driver of this lamp, protection elements are already installed, C1 for protection against pulse surges and R2, R3 for protection against current surges. When checking the elements, resistors R2 were immediately found to be open on both drivers. It appears that the LED lamp was supplied with a voltage that exceeded the permissible voltage. After replacing the resistors, I didn’t have a 10 ohm one at hand, so I set it to 5.1 ohms, and the lamp started working.

Repair of LED lamp series "LLB" LR-EW5N-5

The appearance of this type of light bulb inspires confidence. Aluminum body, high quality workmanship, beautiful design.

The design of the light bulb is such that disassembling it without the use of significant physical effort is impossible. Since the repair of any LED lamp begins with checking the serviceability of the LEDs, the first thing we had to do was remove the plastic protective glass.

The glass was fixed without glue on a groove made in the radiator with a collar inside it. To remove the glass, you need to use the end of a screwdriver, which will go between the fins of the radiator, to lean on the end of the radiator and, like a lever, lift the glass up.

Checking the LEDs with a tester showed that they are working properly, therefore, the driver is faulty and we need to get to it. The aluminum board was secured with four screws, which I unscrewed.

But contrary to expectations, behind the board there was a radiator plane, lubricated with heat-conducting paste. The board had to be returned to its place and the lamp continued to be disassembled from the base side.

Due to the fact that the plastic part to which the radiator was attached was held very tightly, I decided to go the proven route, remove the base and remove the driver through the opened hole for repair. I drilled out the core points, but the base was not removed. It turned out that it was still attached to the plastic due to the threaded connection.

I had to separate the plastic adapter from the radiator. It held up just like the protective glass. To do this, a cut was made with a hacksaw for metal at the junction of the plastic with the radiator and by turning a screwdriver with a wide blade, the parts were separated from each other.

After unsoldering the leads from the LED printed circuit board, the driver became available for repair. The driver circuit turned out to be more complex than previous light bulbs, with an isolation transformer and a microcircuit. One of the 400 V 4.7 µF electrolytic capacitors was swollen. I had to replace it.

A check of all semiconductor elements revealed a faulty Schottky diode D4 (pictured below on the left). There was an SS110 Schottky diode on the board, which was replaced with an existing analog 10 BQ100 (100 V, 1 A). The forward resistance of Schottky diodes is two times less than that of ordinary diodes. The LED light came on. The second light bulb had the same problem.

Repair of LED lamp series "LLB" LR-EW5N-3

This LED lamp is very similar in appearance to the "LLB" LR-EW5N-5, but its design is slightly different.

If you look closely, you can see that at the junction between aluminum radiator and spherical glass, unlike LR-EW5N-5, there is a ring in which the glass is fixed. To remove the protective glass, use a small screwdriver to pry it at the junction with the ring.

Three nine super-bright crystal LEDs are installed on an aluminum printed circuit board. The board is screwed to the heatsink with three screws. Checking the LEDs showed their serviceability. Therefore, the driver needs to be repaired. Having experience in repairing a similar LED lamp "LLB" LR-EW5N-5, I did not unscrew the screws, but unsoldered the current-carrying wires coming from the driver and continued disassembling the lamp from the base side.

The plastic connecting ring between the base and the radiator was removed with great difficulty. At the same time, part of it broke off. As it turned out, it was screwed to the radiator with three self-tapping screws. The driver was easily removed from the lamp body.

The screws that fasten the plastic ring of the base are covered by the driver, and it is difficult to see them, but they are on the same axis with the thread to which the transition part of the radiator is screwed. Therefore, you can reach them with a thin Phillips screwdriver.

The driver turned out to be assembled according to a transformer circuit. Checking all elements except the microcircuit did not reveal any failures. Consequently, the microcircuit is faulty; I couldn’t even find a mention of its type on the Internet. The LED light bulb could not be repaired; it will be useful for spare parts. But I studied its structure.

Repair of LED lamp series "LL" GU10-3W

Disassemble the burnt out LED light bulb GU10-3W with protective glass turned out to be, at first glance, impossible. An attempt to remove the glass resulted in its chipping. When great force was applied, the glass cracked.

By the way, in the lamp marking the letter G means that the lamp has a pin base, the letter U means that the lamp belongs to the class energy saving light bulbs, and the number 10 is the distance between the pins in millimeters.

LED light bulbs with a GU10 base have special pins and are installed in a socket with a rotation. Thanks to the expanding pins, the LED lamp is pinched in the socket and held securely even when shaking.

In order to disassemble this LED light bulb it was necessary to aluminum housing Drill a hole with a diameter of 2.5 mm at the level of the surface of the printed circuit board. The drilling location must be chosen in such a way that the drill does not damage the LED when exiting. If you don’t have a drill at hand, you can make a hole with a thick awl.

Next, a small screwdriver is inserted into the hole and, acting like a lever, the glass is lifted. I removed the glass from two light bulbs without any problems. If checking the LEDs with a tester shows their serviceability, then the printed circuit board is removed.

After separating the board from the lamp body, it immediately became obvious that the current-limiting resistors had burned out in both one and the other lamp. The calculator determined their nominal value from the stripes, 160 Ohms. Since the resistors burned out in LED bulbs of different batches, it is obvious that their power, judging by the size of 0.25 W, does not correspond to the power released when the driver operates at maximum temperature environment.

The driver circuit board was well filled with silicone, and I did not disconnect it from the board with the LEDs. I cut off the leads of the burnt resistors at the base and soldered them to more powerful resistors that were on hand. In one lamp I soldered a 150 Ohm resistor with a power of 1 W, in the second two in parallel with 320 Ohms with a power of 0.5 W.

In order to prevent accidental contact with the terminal of the resistor to which the mains voltage is suitable metal body lamp, it was insulated with a drop of hot melt glue. It is waterproof and an excellent insulator. I often use it to seal, insulate and secure electrical wires and other parts.

Hot melt adhesive is available in the form of rods with a diameter of 7, 12, 15 and 24 mm in different colors, from transparent to black. It melts, depending on the brand, at a temperature of 80-150°, which allows it to be melted using an electric soldering iron. It is enough to cut a piece of the rod, place it in the right place and heat it. Hot-melt glue will acquire the consistency of May honey. After cooling it becomes hard again. When reheated it becomes liquid again.

After replacing the resistors, the functionality of both bulbs was restored. All that remains is to secure the printed circuit board and protective glass in the lamp body.

When repairing LED lamps, I used “Installation” moment liquid nails to secure printed circuit boards and plastic parts. The glue is odorless, adheres well to the surfaces of any materials, remains plastic after drying, and has sufficient heat resistance.

Enough to take a small amount of glue onto the end of a screwdriver and apply to the contact points of the parts. After 15 minutes the glue will already hold.

When gluing the printed circuit board, in order not to wait, holding the board in place, since the wires were pushing it out, I additionally fixed the board at several points using hot glue.

The LED lamp began to flash like a strobe light

I had to repair a couple of LED lamps with drivers assembled on a microcircuit, the malfunction of which was the light blinking at a frequency of about one hertz, like in a strobe light.

One instance of the LED lamp began to blink immediately after being turned on for the first few seconds and then the lamp began to shine normally. Over time, the duration of the lamp's blinking after switching on began to increase, and the lamp began to blink continuously. The second instance of the LED lamp suddenly began blinking continuously.

After disassembling the lamps, it turned out that the electrolytic capacitors installed immediately after the rectifier bridges in the drivers had failed. It was easy to determine the malfunction, since the capacitor housings were swollen. But even if the capacitor looks free of external defects in appearance, then the repair of an LED light bulb with a stroboscopic effect must still begin with its replacement.

After replacing the electrolytic capacitors with working ones, the stroboscopic effect disappeared and the lamps began to shine normally.

Online calculators for determining resistor values
by color marking

When repairing LED lamps, it becomes necessary to determine the resistor value. According to the standard, modern resistors are marked by applying rings of different colors to their bodies. Simple resistors have 4 colored rings, and high-precision resistors have 5 rings.

Despite the diversity on the country's shelves, they remain unrivaled due to their cost-effectiveness and durability. However, a quality product is not always purchased, because in a store you cannot take the product apart for inspection. And even in this case, it is not a fact that everyone will determine from what parts it is assembled. burn out, and buying new ones becomes expensive. The solution is to repair LED lamps yourself. Even a novice home craftsman can do this work, and the parts are inexpensive. Today we will figure out how to check in what cases the product is repaired and how to do it.

It is known that LEDs cannot operate directly from a 220 V network. To do this, they need additional equipment, which, most often, fails. We'll talk about it today. Let's consider the circuit, without which the operation of the lighting device is impossible. At the same time, we will conduct an educational program for those who do not understand anything about radio electronics.

The 220 V LED lamp driver circuit consists of:

diode bridge;
resistance;
resistors.

The diode bridge serves to rectify the current (converts it from alternating to direct). On the graph it looks like cutting off a half-wave of a sine wave. Resistors limit the current, and capacitors store energy, increasing the frequency. Let's look at the operating principle of a 220 V LED lamp.

The principle of operation of the driver in an LED lamp

View on the diagram	Operating procedure
	A voltage of 220 V is supplied to the driver and passes through a smoothing capacitor and a current-limiting resistor. This is necessary in order to protect the diode bridge.
	Voltage is supplied to a diode bridge, consisting of four differently directed diodes, which cut off the half-wave of the sine wave. The output current is constant.
	Now, by means of a resistance and a capacitor, the current is again limited and the desired frequency is set.
	Voltage with necessary parameters is supplied to unidirectional light diodes, which also serve as current limiting. Those. when one of them burns out, the voltage increases, which leads to failure of the capacitor if it is not powerful enough. This happens in Chinese products. High-quality devices are protected from this.

Having understood the principle of operation and the driver circuit, the decision on how to repair a 220V LED lamp will no longer seem difficult. If we talk about quality products, then you shouldn’t expect any troubles from them. They work for the entire prescribed period and do not fade, although there are “diseases” to which they are also susceptible. Let's talk about how to deal with them now.

Reasons for failure of LED lighting devices

To make it easier to understand the reasons, let’s summarize all the data in one common table.

Cause of failure	Description	Solution
Voltage drops	Such lamps are less susceptible to breakdowns due to voltage surges, however, sensitive surges can “break through” the diode bridge. As a result, the LED elements burn out.	If surges are sensitive, you need to install one, which will significantly extend the life of the lighting equipment, but also other household appliances.
Incorrectly selected lamp	Lack of proper ventilation affects the driver. The heat it generates is not removed. The result is overheating.	Choose one with good ventilation that will provide the necessary heat exchange.
Installation errors	Incorrectly selected lighting system and its connection. Incorrectly calculated electrical wiring cross-section.	Here the solution would be to unload the lighting line or replace lighting fixtures with devices that consume less power.
External factor	Increased humidity, vibration, shock or dust if the IP is incorrectly selected.	Correct selection or elimination of negative factors.

Good to know! Repair of LED lamps cannot be carried out indefinitely. It is much easier to eliminate negative factors that affect durability and not purchase cheap products. Savings today will result in costs tomorrow. As economist Adam Smith said, “I am not rich enough to buy cheap things.”

Repairing a 220 V LED lamp with your own hands: nuances of the work

Before you repair an LED lamp with your own hands, pay attention to some details that require less labor. Checking the cartridge and the voltage in it is the first thing to do.

Important! Repairing LED lamps requires a multimeter - without it you will not be able to ring the driver elements. You will also need a soldering station.

A soldering station is necessary for repairing LED chandeliers and lamps. After all, overheating of their elements leads to failure. The heating temperature when soldering should be no higher than 2600, while the soldering iron heats up more. But there is a way out. We use a piece of copper wire with a cross-section of 4 mm, which is wound onto the soldering iron tip in a tight spiral. The more you lengthen the tip, the lower its temperature. It is convenient if the multimeter has a thermometer function. In this case, it can be adjusted more accurately.

But before you make any repairs LED spotlights, chandeliers or lamps, you need to determine the cause of failure.

How to disassemble an LED light bulb

One of the problems that a novice home DIYer faces is how to disassemble an LED light bulb. To do this you will need an awl, solvent and a syringe with a needle. The LED lamp diffuser is glued to the body with sealant, which needs to be removed. Carefully running an awl along the edge of the diffuser, inject the solvent with a syringe. After 2-3 minutes, easily twisting, the diffuser is removed.

Some lighting fixtures are made without sealant. In this case, it is enough to rotate the diffuser and remove it from the body.

Determining the cause of failure of an LED light bulb

Having disassembled lighting fixture, pay attention to the LED elements. Burnt is often identified visually: it has scorch marks or black dots. Then we replace the faulty part and check its functionality. We will tell you in detail about the replacement in step-by-step instructions.

If the LED elements are in order, move on to the driver. To check the functionality of its parts, you need to remove them from the printed circuit board. The value of resistors (resistances) is indicated on the board, and the parameters of the capacitor are indicated on the case. When testing with a multimeter in the appropriate modes, there should be no deviations. However, often failed capacitors are identified visually - they swell or burst. Solution - replacement with suitable technical parameters.

Replacing capacitors and resistances, unlike LEDs, is often done with a regular soldering iron. In this case, care should be taken not to overheat nearby contacts and elements.

Replacing light bulb LEDs: how difficult is it?

If you have a soldering station or hair dryer, this work is simple. It is more difficult to work with a soldering iron, but it is also possible.

Good to know! If you don’t have working LED elements at hand, you can install a jumper instead of the burnt one. Such a lamp will not work for a long time, but it will be possible to gain some time. However, such repairs are carried out only if the number of elements is more than six. Otherwise, a day is the maximum work of the repair product.

Modern lamps operate on SMD LED elements, which can be desoldered from the LED strip. But it is worth choosing the ones that are suitable according to technical characteristics. If there are none, it is better to change everything.

Related article:

For the right choice You need to know not only general things about LED devices. Information about modern models, electrical diagrams of working devices. In this article you will find answers to these and other practical questions.

Repairing an LED lamp driver if you have an electrical diagram of the device

If the driver consists of SMD components that are smaller in size, we will use a soldering iron with copper wire on the sting. At visual inspection A burnt element has been identified - unsolder it and select the appropriate one according to the markings. There are no visible damages - this is more difficult. You will have to solder all the parts and ring them separately. Having found a burnt one, we replace it with a functional one. It is convenient to use tweezers for this.

Helpful advice! You should not remove all elements from the printed circuit board at the same time. They are similar in appearance, you can later confuse the location. It is better to unsolder the elements one by one and, after checking, mount them in place.

How to check and replace the power supply of LED lamps

When installing lighting in rooms with high humidity (or), stabilizing ones are used, which reduce the voltage to a safe one (12 or 24 volts). The stabilizer can fail for several reasons. The main ones are excess load (power consumption of lamps) or incorrect choice degree of block protection. Such devices are repaired in specialized services. At home, this is unrealistic without equipment and knowledge in the field of radio electronics. In this case, the power supply will have to be replaced.

Very important! All work to replace the stabilizing LED power supply is carried out with the voltage removed. Don't rely on the switch - it may not be connected correctly. The voltage is turned off in the apartment's distribution panel. Remember that touching live parts with your hand is dangerous.

We need to pay attention to specifications devices - the power must exceed the parameters of the lamps that are powered from it. Having disconnected the failed unit, we connect a new one according to the diagram. She is in technical documentation device. This does not present any difficulties - all wires have color coding, and contacts – letter designation.

The degree of protection of the device (IP) also plays a role. For a bathroom, the device must be marked at least IP45.

Article

Nowadays, the issue of energy saving arises more and more often. To solve this issue, manufacturers produce energy-saving lamps(fluorescent), having a base similar to that of standard 220 volt incandescent lamps.

The electricity consumption of this type of electric lamps is undoubtedly significantly less than that of simple lamps incandescent 220 volt. In turn, their designated service life is approximately 5000 hours, that is, approximately 5 times longer than the service life of a conventional lamp.

With all the advantages of this electric lamp, there is also a disadvantage - the high price. These lamps use a special electronic ballast, but although it breaks very rarely, the filaments of this electric lamp burn out quite often, often without even working out the declared service life.

But now super-bright ones are being produced, which in turn can be used to make a homemade LED lamp with your own hands. The service life of current LEDs reaches approximately 50,000 hours, which is almost 6 years of constant operation.

Described in this article DIY LED lamp 220V specially created for power supply from a 220 V power supply.

Description of a 220 volt power source for a homemade LED lamp

The electrical circuit is quite simple and does not require adjustment. A special feature of this lamp is the use of LEDs with a large radiation angle, resulting in an even and bright light. In turn, the advantages of this lamp include very low power consumption (about 2 W) and increased efficiency.

The main element of the electrical circuit is ultra-bright LEDs (25 pieces) of the white emission spectrum. In the role of HL1 - HL25, it is better to use LEDs with an emission angle of 160 degrees, for example, brand 5WW4SC. They can be replaced with other LEDs with a direct voltage of 3.2 to 3.7 volts and a current consumption of about 20 mA.

The LEDs are powered from, which consists of a quenching C1, R1, a rectifying bridge on VD1...VD4, a smoothing capacitance C2 and a limiting resistance R2.

The mains voltage of 220 volts is extinguished by a circuit of elements R1, C1, R2. Capacity C1 must have a voltage of at least 250 V. Then undervoltage goes to the rectifier bridge, and then through the capacitive filter C2 the voltage is supplied to the series-connected LEDs HL1 - HL25. When using 37 LEDs in a circuit, you can remove resistance R2.

This circuit provides the ability to protect LEDs from surge high voltage 220 volt. It consists of an 80 mA fuse and (TVR05361 or FNR05361). When increasing mains voltage The varistor resistance drops sharply, causing the fuse to blow.