LED light sources are quickly gaining popularity and are crowding out uneconomical incandescent lamps and hazardous fluorescent counterparts. They efficiently consume energy, serve for a long time, and some of them are subject to repair after failure.
To correctly replace or repair a broken element, you will need a LED lamp circuit and knowledge of the structural features. And we examined this information in detail in our article, paying attention to the varieties of lamps and their design. We also gave a brief overview of the device of the most popular led models from well-known manufacturers.
How is the LED lamp arranged?
A close acquaintance with the design of LED-luminaire 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 in their hands, can independently assemble a lamp on LEDs, but this is beyond the reach of a beginner.
Considering that devices with LEDs have become the basis of lighting systems for modern apartments, the ability to understand the arrangement of lamps and repair them can save a significant part of the family budget
But, having studied the circuit and having basic skills in working with electronics, even a novice will be able to disassemble the lamp, replace the broken parts, restoring the functionality of the device. For detailed instructions on identifying breakdowns and self-repairing an LED lamp, please click here.
Does repairing an LED lamp make sense? Of course. Unlike analogues with an incandescent filament at 10 rubles apiece, LED devices are expensive.
Suppose GAUSS “pear” is about 80 rubles, and a better alternative to OSRAM is 120 rubles. Replacing a capacitor, resistor or diode will cost less, and the lamp life can be extended by timely replacement.
There are many modifications of LED lamps: candles, pears, balls, spotlights, capsules, ribbons, etc. They differ in shape, size and design. To visually see the difference from an incandescent lamp, consider a common model in the shape of a pear.
Instead of a glass bulb - a frosted diffuser, the filament was replaced by "long-playing" diodes on the circuit board, the heat sink removes excess heat, and the driver provides voltage stability
If you distract from the usual form, you can notice only one familiar element - the base. The size range of the socles remained the same, so they fit traditional cartridges and do not require a change in the electrical system. But the similarity ends here: the internal arrangement of LED devices is much more complicated than that of incandescent lamps.
LED lamps are not designed to work directly from a 220 V network, so a driver is included inside the device, which is also a power and control unit. It consists of many small elements whose main task is to rectify the current and reduce the voltage.
Varieties of schemes and their features
To create the optimal voltage for the device to work on diodes, the driver is assembled on the basis of a circuit with a capacitor or step-down transformer. The first option is cheaper, the second is used to equip powerful lamps.
There is a third variety - inverter circuits that implement either for the assembly of dimmable lamps, or for devices with a large number of diodes.
Option # 1 - with capacitors to reduce voltage
Consider an example involving a capacitor, since such circuits are common in household lamps.
An elementary diagram of the LED lamp driver. The main elements that suppress the voltage are capacitors (C2, C3), but the resistor R1 performs the same function
Capacitor C1 protects against electrical interference, and C4 smooths out ripples. At the moment of supply of current, two resistors - R2 and R3 - limit it and simultaneously protect against short circuit, and the 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.
A multimeter is often used to check the capacitor.
Cons of the circuit with capacitors:
- Possible burnout diodes, since the stability of the current supply is not observed. The voltage at the load is completely dependent on the supply voltage.
- No galvanic isolationtherefore there is a risk of electric shock. When disassembling the lamps, it is not recommended to touch live parts, as they are under phase.
- It is almost impossible to achieve high luminous currents, because this will require an increase in the capacitance of the capacitors.
However, there are also many advantages, it is thanks to them that capacitors remain popular. The advantages are ease of assembly, a wide range of output voltages and low cost.
You can safely experiment with self-production, especially since some of the details will be found in old receivers or televisions.
Option # 2 - with a pulse driver
Unlike a linear driver with a capacitor, a pulse driver effectively protects the LEDs from voltage surges and noise in the network.
An example of a pulse device is the popular electronic model CPC9909. Let us consider in more detail its features. 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 of LED lights, including increased power. The controller is enclosed 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.
Scheme of the LED driver based on the CPC9909 chip. Advantages of the circuit: the ability to work in the temperature range from -55 ° C to +85 ° C and powered by AC voltage
The chip is successfully used for the development of emergency and backup lighting power grids, as it is suitable for boost converter circuits.
At home, based on CPC9909, they most often assemble luminaires with battery power or drivers with a power not exceeding 25 V.
Option # 3 - with a dimmable driver
Adjusting the brightness of the lighting allows you to set the desired level of lighting in the room. This is useful when creating separate zones, reducing the brightness of light in the daytime, or to emphasize interior items.
Using a dimmer, the use of electricity becomes more rational, and the service life of the electrical appliance increases.
Sample lamp in the style of "retro" with a dimmer. In appearance, the desktop lighting device resembles a kerosene lamp and on the side has a knob for controlling the brightness of the glow
There are two types of dimmable drivers, each of which has its own advantages. The first 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 control is a creeping line.
Testing a 40W dimmable driver. It is designed for office fixtures, as well as devices for car parking and public buildings where an 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 adjusting the current, a change in the shade of the glow can occur: white diodes, when the current decreases, slightly yellow light emits, and when the current increases, blue.
Short review and testing of popular LED lamps
Although the principles for constructing driver circuits for different lighting devices are similar, there are differences between them both in the sequence of connecting elements and in their choice.
Consider the scheme of 4 lamps, which are sold in the public domain. If desired, they can be repaired with their own hands.
Image Gallery
Photo from
Disassembled Lamp Driver BBK P653F
Compact lamp Ecola 7w
Collapsible analog of Ecola GU5.3
Jazzway 7.5w GU10 - suitable for repair
If you have experience working with controllers, you can replace circuit elements, re-solder 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 device.
Option # 1 - BBK P653F LED Lamp
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 principles of the first device.
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 filtering capacitor, which should be at the output
The design is easy to detect flaws. For example, the installation location of the controller: partly in the radiator, in the absence of insulation, partly in the base. The assembly on the SM7525 chip produces 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 printed circuit board with a thickness of half a millimeter, 14 diodes are connected in series.
Between the radiator and the board there is a layer of heat-conducting paste. The base is fixed with screws.
The controller circuit is simple, implemented on a compact board. LEDs heat the base plate to +55 ºС. There are practically no ripples, radio interference is also excluded
The board is completely placed inside the base and connected by shortened wires. Short-circuiting 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 repair or improve the device driver.
However, the unsightly appearance and design of the device spoils the impression. The overall radiator makes the weight heavier, therefore, when fixing the lamp to the cartridge, additional fixation is recommended.
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 filtering capacitor, which should be at the output
The disadvantage of this scheme is the presence of noticeable pulsations of the light flux and a high degree of radio interference, which will certainly affect the life of the device. The basis of the controller is the BP3122 chip, the output indicator is 9.6 V.
More information about Ecola brand LED bulbs we reviewed in our other article.
Option # 4 - Jazzway 7.5w GU10 Lamp
The external elements of the lamp detach easily, so the controller can be reached quickly enough by unscrewing two pairs of screws. The protective glass is held on latches. 17 diodes with serial communication are fixed on the board.
However, the controller itself, located in the base, is generously flooded with a compound, and the wires are pressed into the terminals. To free them, you need to use a drill or apply a wiring.
The disadvantage of this 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
Radio interference is not observed - and all due to the lack of a pulse controller, but at a frequency of 100 Hz tangible pulsations of light are observed, reaching up to 80% of the maximum value.
The result of the controller is 100 V at the output, but according to a general assessment, the lamp is more likely to be a weak instrument. Its cost is clearly overestimated and equated to the cost of brands that are characterized by stable product quality.
Other features and characteristics of the lamps of this manufacturer are given in the next article.
How the drivers for LEDs are arranged, what are their features and functions can be found in the videos below.
Analysis of the circuit of the LED lamp MR-16:
Driver scheme for self-assembly of lamps with power up to 15W:
How the FT833A driver looks and acts:
Homemade items at hand:
Now on commercial Internet sites you can purchase kits and individual elements for assembling lighting devices of various capacities.
If desired, you can repair a failed LED lamp or modify a new one to get the best result. When buying, we recommend that you carefully check the characteristics and compliance of parts.
Do you have questions after reading the above material? Or do you want to add valuable information and other light bulb schemes based on personal experience in repairing led lamps? Write your recommendations, add photos and schemes, ask questions in the comments section below.