Electric drivers for LED lamps. Drivers for LEDs - everything a DIYer needs to know. Current source and voltage source

The advantages of LED paws have been reviewed many times. The abundance of positive feedback from users of LED lighting, willy-nilly, makes you think about Ilyich's own bulbs. Everything would be nice, but when it comes to calculating the conversion of an apartment to LED lighting, the numbers are a little "annoying".

To replace an ordinary 75W lamp, there is a 15W LED bulb, and a dozen of such lamps need to be changed. With an average cost of about $ 10 per lamp, the budget comes out decent, and even the risk of purchasing a Chinese "clone" with a life cycle of 2-3 years cannot be ruled out. In light of this, many are considering the possibility of self-manufacturing these devices.

Theory of power supply of LED lamps from 220V

Most a budget option you can do it yourself from these LEDs. A dozen of these babies cost less than a dollar, and the brightness corresponds to a 75W incandescent lamp. Putting everything together is not a problem, but you can't connect them directly to the network - they will burn. The heart of any LED lamp is the power driver. How long and well the light bulb will shine depends on it.

To assemble a 220-volt LED lamp with your own hands, let's figure out the power driver circuit.

The network parameters significantly exceed the needs of the LED. In order for the LED to be able to work from the network, it is required to reduce the voltage amplitude, current strength and convert the alternating voltage of the network to constant.

For these purposes, a voltage divider with a resistor or capacitive load and stabilizers are used.

Diode light components

A 220 volt LED lamp circuit will require a minimum of available components.

• 3.3V 1W LEDs - 12 pcs .;
• ceramic capacitor 0.27mkF 400-500V - 1 pc .;
• resistor 500kΩ - 1MΩ 0.5 - 1W - 1 sh.t;
• diode for 100V - 4 pcs.;
• electrolytic capacitors at 330mkF and 100mkF 16V, 1 pc .;
• voltage regulator for 12V L7812 or similar - 1pc.

DIY 220V LED driver making

The 220 volt ice driver circuit is nothing more than a switching power supply.

As a home-made LED driver from a 220V network, we will consider the simplest switching power supply without galvanic isolation. The main advantage of such schemes is simplicity and reliability. But be careful when assembling, as such a circuit has no current limit. The LEDs will select their intended one and a half amperes, but if you touch the bare wires with your hand, the current will reach ten amperes, and such a shock is very noticeable.

The simplest driver circuit for 220V LEDs consists of three main stages:

• Capacitive voltage divider;
• diode bridge;
• voltage stabilization stage.

First stage - the capacitive resistance across the capacitor C1 with a resistor. The resistor is necessary for the self-discharge of the capacitor and does not affect the operation of the circuit itself. Its rating is not particularly critical and can be from 100kΩ to 1MΩ with a power of 0.5-1W. The capacitor is not necessarily electrolytic at 400-500V (effective peak voltage of the network).

When a half-wave of voltage passes through a capacitor, it passes current until the plates are charged. The smaller its capacity, the faster it is fully charged. With a capacity of 0.3-0.4 μF, the charging time is 1/10 of the half-wave period of the mains voltage. In simple terms, only a tenth of the incoming voltage will pass through the capacitor.

Second stage - diode bridge. It converts AC voltage to DC voltage. After cutting off most of the half-wave of the voltage by the capacitor, at the output of the diode bridge we get about 20-24V direct current.

Third cascade - smoothing stabilizing filter.

The diode bridge capacitor acts as a voltage divider. When the voltage in the network changes, the amplitude at the output of the diode bridge will also change.

To smooth the voltage ripple in parallel with the circuit, connect electrolytic capacitor... Its capacity depends on the power of our load.

In the driver circuit, the supply voltage for the LEDs should not exceed 12V. The common element L7812 can be used as a stabilizer.

The assembled circuit of a 220-volt LED lamp starts working immediately, but carefully isolate all bare wires and soldering points of circuit elements before connecting to the network.

Driver option without current stabilizer

There are a huge number of driver circuits on the network for LEDs from a 220V network that do not have current stabilizers.

The problem with any transformerless driver is the ripple of the output voltage, and therefore the brightness of the LEDs. The capacitor installed after the diode bridge partially solves this problem, but does not completely solve it.

The diodes will have a ripple with an amplitude of 2-3V. When we install a 12V regulator in the circuit, even with ripple, the amplitude of the input voltage will be above the cut-off range.

Voltage diagram in a circuit without a stabilizer

Diagram in a circuit with a stabilizer

Therefore, the driver for diode lamps, even assembled by hand, in terms of the ripple level will not be inferior to similar units of expensive factory-made lamps.

As you can see, assembling the driver with your own hands is not particularly difficult. By changing the parameters of the circuit elements, we can vary the values \u200b\u200bof the output signal within a wide range.

If you have a desire to build a 220 volt LED floodlight circuit based on such a circuit, it is better to remake the output stage for 24V voltage with an appropriate stabilizer, since the output current of the L7812 is 1.2A, this limits the load power to 10W. For more powerful light sources, either increase the number of output stages, or use a more powerful stabilizer with an output current of up to 5A and install it on a radiator.

How to check the driver for LEDs for operability and compliance with the declared power parameters can be found in the video:

LED spotlight matrix check:

Types of drivers by device type

There are two types of LED drivers:

• Linear. A typical linear driver circuit is based on a P-channel transistor. This device is best used if the input voltage is unstable. It provides smoother current stabilization, is reliable in operation and has affordable price... Despite these disadvantages, this driver is not widely used. It is characterized by low efficiency, generates a lot of heat during operation and cannot be used to connect powerful ones.

• Pulse. The principle of operation is based on pulse width modulation. The efficiency of current conversion of such devices reaches 95%. They have small size, emit little heat, protect from the negative effects of external factors. Their use has a positive effect on the lifetime of LED lighting.

Important! Impulse drivers have a fairly high level of electromagnetic interference. In theory, people using pacemakers may feel discomfort from being in a room lit by such devices. However, as practice has shown, in order for the pacemaker to be influenced by the magnetic field of the driver, it is necessary to find a person at a distance of less than a meter from a high-power LED-floodlight.

Dimmable LED Drivers

In most cases, modern LED drivers include devices that regulate the brightness of lighting fixtures. The application allows you to set a comfortable level of lighting in the room. In addition, it saves the working life of LED illuminators.

The dimming device can be located between the power supply and the LED illuminator. Such devices directly control the energy supplied to the LEDs. As a rule, these are pulse devices based on PWM control. They regulate the amount of current flowing. In some cases, when using budget LED sources, negative effects such as flickering may be observed.

The second type of dimmer converters controls the power supply. In principle, their influence is both PWM regulation and control of the current flowing through the device. In this case, not only a change in the brightness, but also the color of the LEDs can be observed. For example, white LEDs with this adjustment can emit a yellowish light when the intensity is reduced and a bright blue exaggeration.

Diy LED driver circuit based on PT4115 with dimmer

The use of PT4115 in the driver circuit allows the use of several types of power supplies: with a voltage of 12-240 V and 12-18 V in the second case, a diode bridge with a capacitor installed at the output must be introduced into the general circuit of the LED driver with PT4115.

Making a driver for LEDs with your own hands

Illustration	Description of work
	To facilitate the work, you can take the old one from your mobile phone.
	The device actually is and includes almost all the necessary radio components for connecting several one-watt LEDs.
	A limiting resistor must be removed from the circuit, which protects the phone from supplying excessive voltage. In this case, it is a 5K resistor located at the output channel.
	In place of the static resistor, you need to solder a trimmer. At first, it is advisable to set it to the same 5 kOhm. During the tuning process, the voltage can be raised to the desired level.
	The output channel is connected to 3 LEDs in series. Provided that they have a power of 1 W, the total power consumption at the output is 3 W.

must be connected to the mains through special devices that stabilize the current - drivers for LEDs. These are 220 V AC to DC voltage converters with the parameters necessary for the operation of light diodes. Only if they are available, it is possible to guarantee stable operation, long service life of LED sources, declared brightness, protection against short circuits and overheating. The choice of drivers is small, so it is better to first purchase a converter, and then select it for it. You can assemble the device yourself using a simple scheme. Read about what a driver for an LED is, which one to buy and how to use it correctly in our review.

Are semiconductor elements. The current, not the voltage, is responsible for the brightness of their glow. For them to work, you need a stable current of a certain value. With a p-n junction, the voltage drops by the same number of volts for each element. It is the driver's task to ensure the optimal operation of LED sources, taking into account these parameters.

What power is needed and how much it drops during the p-n junction should be indicated in the passport data of the LED device. The range of the inverter parameters must fit within these values.

Essentially, a driver is. But the main output parameter of this device is stabilized current. They are produced on the principle of PWM conversion using special microcircuits or based on transistors. The latter are called simple.

The converter is powered from a regular network, at the output it gives out a voltage of the specified range, which is indicated in the form of two numbers: the minimum and maximum values. Usually from 3 V to several tens. For example, using a converter with an output voltage of 9-21 V and a power of 780 mA, it is possible to ensure the operation of 3-6, each of which creates a drop in the network by 3 V.

Thus, the driver is a device that converts current from the 220 V network to the specified parameters lighting fixtureensuring its normal operation and long service life.

Where is used

The demand for converters is growing along with the popularity of LEDs. Are economical, powerful and compact devices. They are used for a variety of purposes:

• for lanterns;
• at home;
• for arrangement;
• in car and bicycle headlights;
• in small lanterns;

When connecting to a 220 V network, a driver is always needed; in the case of using a constant voltage, it is permissible to do with a resistor.

How the device works

The principle of operation of LED drivers for LEDs is to maintain a given current at the output, regardless of voltage changes. The current passing through the resistances inside the device stabilizes and acquires the desired frequency. Then it passes through a rectifying diode bridge. At the output, we get a stable forward current, sufficient to operate a certain number of LEDs.

Key driver features

Key parameters of devices for current conversion, which you need to rely on when choosing:

1. The rated power of the device. It is listed in the range. The maximum value must necessarily be slightly higher than the power consumption of the connected lighting device.
2. Output voltage. The value must be greater than or equal to the total voltage drop across each circuit element.
3. Rated current. Must match the wattage of the fixture to provide sufficient brightness.

Depending on these characteristics, they determine which LED sources can be connected using a specific driver.

Types of current converters by device type

Drivers of two types are produced: linear and impulse. They have one function, but the scope of application, technical features and the cost is different. Comparison of converters different types presented in the table:

Device type	Specifications	pros	Minuses	Scope of application
	Current generator on a p-channel transistor, smoothly stabilizes the current at alternating voltage	No interference, inexpensive	Efficiency less than 80%, very hot	Low-power LED lamps, strips, flashlights
	Powered by pulse width modulation	High efficiency (up to 95%), suitable for powerful devices, prolongs the life of the elements	Creates electromagnetic interference	Car tuning, street lighting, household LED sources

How to choose a driver for LEDs and calculate its technical parameters

The driver for the LED strip is not suitable for the powerful street lamp and vice versa, therefore, it is necessary to calculate the basic parameters of the device as accurately as possible and take into account the operating conditions.

Parameter	What does it depend on	How to calculate
Calculating device power	Determined by the power of all connected LEDs	Calculated by the formula P \u003d PLED-source × n where P Is the power of the driver; PLED source - power of one connected element; n - amount of elements. For a power reserve of 30%, you need to multiply P by 1.3. The resulting value is the maximum driver power required to connect the lighting fixture
Output voltage calculation	Determined by the voltage drop across each element	The value depends on the color of the glow of the elements, it is indicated on the device itself or on the packaging. For example, 9 green or 16 red LEDs can be connected to a 12V driver.
Current calculation	Depends on LED power and brightness	Determined by the parameters of the connected device

The converters are available with or without housing. The former look more aesthetic and are protected from moisture and dust, the latter are used for hidden installation and are cheaper. Another characteristic that must be taken into account is the permissible operating temperature. It is different for linear and pulse converters.

Important! The packaging with the device must indicate its main parameters and manufacturer.

Ways of connecting current transformers

LEDs can be connected to the device in two ways: in parallel (in several strings with the same number of elements) and in series (one by one in one circuit).

To connect 6 cells, the voltage drop of which is 2 V, in parallel in two lines, a 6 V 600 mA driver is needed. And when connected in series, the converter must be rated for 12 V and 300 mA.

A daisy-chain connection is better because all LEDs will glow the same, while in parallel connection, the brightness of the lines may differ. When connecting a large number of elements in series, a driver with a high output voltage will be required.

Dimmable LED current converters

Is the regulation of the intensity of the light coming from the lighting fixture. Dimmable drivers for allow changing the input and output parameters of the current. This increases or decreases the brightness of the LEDs. When using regulation, it is possible to change the color of the glow. If the power is less, then the white elements may turn yellow, if more, then blue.

Chinese drivers: is it worth saving

Drivers are produced in China in huge quantities. They are distinguished by their low cost, therefore they are quite in demand. They are galvanically isolated. Their technical parameters are often overestimated, so when buying a cheap device it is worth considering this.

Most often these are pulse converters with a power of 350 ÷ 700 mA. They do not always have a case, which is even convenient if the device is purchased for the purpose of experimentation or training.

Disadvantages of Chinese products:

• simple and cheap microcircuits are used as a basis;
• devices do not have protection against network fluctuations and overheating;
• create radio interference;
• create a high-level ripple at the output;
• do not last long and are not guaranteed.

Not all Chinese drivers are bad, there are also more reliable devices, for example, based on PT4115. They can be used to connect household LED sources, flashlights, tapes.

Driver life

The lifespan of an LED driver ice depends on the external conditions and the initial quality of the device. The estimated service life of the driver is from 20 to 100 thousand hours.

The following factors can affect the service life:

• temperature drops;
• high humidity;
• power surges;
• incomplete load of the device (if the driver is designed for 100 W, but uses 50 W, the voltage returns back, from which an overload occurs).

Well-known manufacturers give a guarantee for drivers, on average for 30 thousand hours. But if the device has been used incorrectly, the buyer is responsible. If the LED source does not turn on or there may be a problem with the converter, incorrect connection, or a malfunction of the lighting fixture itself.

How to check the LED driver for performance, see the video below:

Diy diagram of drivers for LEDs with a dimmer based on PT4115

A simple current converter can be assembled on the basis of a ready-made Chinese PT4115 microcircuit. It is robust enough to be used. Chip characteristics:

• Efficiency up to 97%;
• there is an output for a device that regulates brightness;
• protected from load breaks;
• maximum stabilization deviation 5%;
• input voltage 6 ÷ 30 V;
• output power 1.2 A.

The microcircuit is suitable for powering an LED source over 1 W. Has a minimum of strapping components.

Decoding the outputs of the microcircuit:

• SW - output switch;
• DIM - dimming;
• GND - signal and power supply element;
• CIN - capacitor
• CSN - current sensor;
• VIN - supply voltage.

Even a novice wizard can assemble a driver based on this microcircuit.

220V LED lamp driver circuit

The current stabilizer, in the case of c, is installed in the base of the device. And it is performed on the basis of inexpensive microcircuits, for example, CPC9909. Such lamps must be equipped with a cooling system. They last much longer than any others, but it is better to give preference to trusted manufacturers, since in the Chinese one can see manual soldering, asymmetry, lack of thermal paste and other disadvantages that reduce the service life.

How to make a driver for LEDs with your own hands

The device can be made from any unnecessary phone charger. It only takes minimal improvements and the microcircuit can be connected to the LEDs. It is enough to power 3 1 W cells. To connect a more powerful source, you can use boards from fluorescent lamps.

Important! During work, it is necessary to observe safety precautions. Touching exposed parts may cause electric shock up to 400 V.

Photo	The stage of assembling the driver from the charger
	Remove the case from the charger.
	Using a soldering iron, remove the resistor that limits the voltage supplied to the phone.
	Install a trimmer in its place, while it needs to be set to 5 kOhm.
	Solder LEDs in series on the output channel of the device.
	Remove the input channels with a soldering iron, in their place, solder the power cord to connect to the 220 V.
	Check the operation of the circuit, set the desired voltage on the trimmer with the regulator so that the LEDs shine brightly, but do not change color.

An example of a driver circuit for LEDs from a 220 V network

Drivers for LEDs: where to buy and how much they cost

Buy stabilizers for lED lamps and microcircuits for them can be in the store of radio components, electrical engineering and on many online shopping sites. The last option is the most economical. The cost of the device depends on its technical characteristics, type and manufacturer. Average prices for some types of drivers are shown in the table below.

Today, probably, not a single apartment or private house is not complete without LED lighting. And street lighting is gradually changing to economical and durable LED elements. But looking at today's topic of conversation, one asks - what does the driver have to do with it (from English "driver" is translated this way)? This is the first question that comes to mind for a person ignorant of LED lighting. In fact, without such a device, light diodes do not work with a voltage of 220 V. Today we will figure out what function the driver for LEDs performs, how to connect this device and whether it is possible to make it with our own hands.

Read in the article:

Why do you need LED drivers and what is it

The answer to the question of what is a driver for an LED is pretty simple. This is a device that stabilizes the voltage and gives it the characteristics that are needed for the operation of LED elements. To make it clearer, let's draw an analogy with the control gear of a fluorescent lamp, which also cannot work without additional equipment. The only difference is that the driver is compact and fits into the body of the fixture. In fact, it can be called stabilizing starting device or a frequency converter.

Where are stabilizing devices for LED elements used?

LED drivers for LEDs are used in various fields:

• street lights;
• household lighting lamps;
• lED strips and various lighting;
• office lamps with the shape of fluorescent lamps.

Even daytime running lights of cars require the installation of such a device, but everything is much simpler here, you can get by with one resistor. And although the driver for the LED strip (for example) differs in characteristics from the voltage regulator of the light bulb, they perform the same function.

Operating principle of the 220V LED lamp driver circuit

The principle of operation of the device is to maintain the specified current at the output voltage (regardless of its value). This is the difference from the stabilizing power supply, which is responsible for the voltage.

Examining the circuit, we see that the current, passing through the resistances, stabilizes, and the capacitor gives it the desired frequency. Then the rectifying diode bridge comes into play. We get a stabilized forward current on the LEDs, which is re-limited by resistors.

Noteworthy driver features

The characteristics of the converters required in one case or another are determined based on the parameters of LED consumers. The main ones are:

1. Driver rated power - this parameter must exceed the total power consumed by the light diodes that will be in its circuit.
2. Output voltage - depends on the magnitude of the voltage drop across each of the LEDs.
3. Rated current, which depends on the brightness of the glow and the power consumption of the element.

It's important to know! The voltage drop across an LED depends on its color. For example, if 16 red LEDs can be connected to a 12 V power supply, then the maximum number of green ones will already be 9.

Separation of LED drivers by device type

Converters can be divided into two types - linear and pulse. Both types are applicable to LEDs, but the differences between them are noticeable in both cost and performance.

Linear converters are simple in design and low in cost. But such drivers have a significant drawback - the ability to connect only low-power light elements. Part of the energy is spent on heat generation, which contributes to a decrease in the coefficient of performance (COP).

Pulse converters are based on the principle of pulse-width modulation (PWM) and during their operation, the values \u200b\u200bof the output currents are determined by such a parameter as the duty cycle. This means that there is no change in the pulse frequency, but the duty cycle can vary by values \u200b\u200bfrom 10 to 80%. Such drivers can extend the life of LEDs, but they have one drawback. During their operation, it is possible to induce electromagnetic interference. Let's try to figure out how this threatens a person with a simple example.

The person living in the apartment or house has a pacemaker. Moreover, in small room installed a chandelier with a variety of devices powered by impulse ice drivers for. At the same time, the pacemaker may start to malfunction. Of course, this is exaggerated and to create such strong interference, a lot of lamps are needed, which are located at a distance of less than a meter from the pacemaker, but still there is a risk.

How to choose a driver for an LED: some nuances

Before purchasing a converter, the power consumption of the LEDs is calculated. The rated power of the device must exceed this figure by 25 ÷ 30%. Also, the stabilizer must match the output voltage.

If hidden placement is planned, it is better to choose a converter without a housing - the cost will come out lower with the same technical characteristics.

Important! Chinese-made drivers usually do not meet the declared characteristics. You should not save on purchasing a converter "made in from there". It is better to give preference to a Russian manufacturer.

How to connect LED elements to the converter: methods and diagrams

LEDs are connected to the driver in two ways - in series or in parallel. For example, let's take 6 LED emitters with a voltage drop of 2 V. When connecting in series, you need a driver for 12 V and 300 mA. In this case, the glow will be even across all elements.

By connecting the emitters in parallel in a group of 3, we get the opportunity to use a 6 V converter, but already at 600 mA. The problem is that due to the uneven voltage drop, one line will glow brighter than the other.

We calculate the characteristics of the converter for LEDs

For an accurate calculation, we first determine the power consumption of the LEDs. After that, the issue with the connection diagram is resolved - will it be parallel or serial. The output voltage and power rating of the required converter will depend on this. This is all the work to be done. Now in an electrical store or on an online resource, we select a driver according to the calculated indicators.

Good to know! When purchasing a converter, ask the seller for a certificate of conformity for the product. If it is absent, it is better to refrain from buying.

What is a dimmable LED driver

Dimmable is the driver for lED lamp, which supports changing the input current parameters and is capable of changing the output depending on this. This is achieved by changing the glow intensity of the LED emitters. An example would be a controller for a remote controlled LED strip. If desired, it becomes possible to "dim" the lighting in the room, to give rest to the eyes. It is also appropriate if a child sleeps in the room.

Dimming is performed from the remote control, or from a standard mechanical stepless switch.

Chinese converters - what's special about them

Chinese friends are famous for their ability to forge equipment so that it becomes impossible to use it. The same can be said about drivers. When purchasing a Chinese device, be prepared for the overstated declared characteristics, low quality and rapid converter failure. If the first LED lamp in life is going to be assembled, to practice and gain skills in radio electronics, such products are irreplaceable due to their low cost and ease of execution.

What affects the service life of converters

The reasons for the failure of the converter are:

1. Sharp power surges.
2. High humidity if the device does not correspond to the degree of protection.
3. Temperature drops.
4. Insufficient ventilation.
5. Increased dustiness.
6. Incorrect calculation of consumer power.

Any of these causes can be prevented or corrected. This means that it is within the power of the DIYer to extend the life of the stabilizing device.

PT4115 LED driver circuit with dimmer

We are talking about a Chinese manufacturer, which is an exception to the rule. A microcircuit, on the basis of which you can assemble the simplest converter just of its production. The PT4115 microprocessor has good characteristics and is gaining popularity in Russia.

Related article:

If LED lighting and conventional controllers are not suitable, then they are installed, which are slightly different structurally and technically. Today we will figure out what they are, how to choose and even make such a device ourselves.

The figure shows the simplest scheme driver PT4115 for LEDs, which can be assembled by a novice home craftsman without experience in radio electronics. Interesting in the microcircuit is an additional output (DIM) that allows the connection of a dimmer (dimmer).

How to make a driver for LEDs with your own hands

Any novice master can assemble an LED lamp driver circuit. But this will require accuracy and patience. The stabilizing device may not work the first time. To make it clearer for the reader how the work is done, we offer several of the simplest schemes.

As you can see, there is nothing complicated in the driver circuits for LEDs from a 220 V network. Let's try to consider step by step all the stages of work.

DIY step-by-step instructions for making a driver for LEDs

Photo example	Action being performed
	For work, we need a regular power supply for the phone. With it, everything is done quickly and easily.
	After disassembling the charger, we already have an almost full-fledged driver for three one-watt LEDs in our hands, but it needs to be slightly modified.
	We solder the 5 kOhm limiting resistor located near the output channel. It is he who prevents the charger from applying too much voltage to the cell phone.
	Instead of a limiting one, we solder a trimmer resistor, setting the same 5kOhm on it. Subsequently, we add voltage to the required one.
	3 LEDs of 1 W each are soldered to the output channel, connected in series, which in total will give us 3 W.
	We find the input contacts and unsolder them from the printed circuit board. We no longer need them ...
	... and in their place we solder the power cord, which will supply 220 V.
	If desired, you can put a 1 Ohm resistor in the gap, set all indicators with an ammeter. In this case, the LED attenuation range will be wider.
	After complete assembly, we check the performance. Output voltage 5V, LEDs are not lit yet.
	Turning the regulator on the resistor, we see how the LED elements begin to "flare up".

Be careful. From such a converter, you can get a discharge not only at 220 V (from the power cord), but also a blow of the order of 450 V, which is rather unpleasant (tested on yourself).

Very important! Before you check the LED driver for operability and connect it to the power source, you should visually check the correctness of the assembled circuit again. Defeat electric shock is life-threatening, and short-circuiting flash may harm your eyes.

Current converters for light diodes: where to buy and what is the cost

Such devices are purchased in electrical stores or on the Internet. The second option is more cost effective. Plus, many manufacturers offer free shipping. Consider some models with an input voltage of 220 V with technical characteristics and cost as of December 2017.

Photo	Model	Protection class, IP	Output voltage, V	Power, W	Cost, rub.
	DFT-I-40- LD64	20	60-130	45	400
	ZF-AC LD49	40	40-70	54	450
	XS0812-12W PS12	20	24-44	12	200
	PS100 (open)	20	30-36	100	1100
	PF4050A PS50	65	27-36	50	500
	PF100W LD100	65	23-36	100	1000

Looking at the prices, we can say that the independent manufacture of a current converter is more likely to suit those for whom this is only a hobby. Such a device can be purchased quite inexpensively.

Summarize

When choosing a current converter for LED lamps, everything should be carefully calculated. Any inaccuracy can lead to a decrease in the life of the purchased device. Despite the low cost of the stabilizer, it is rather unpleasant to constantly throw money away. Only in this case, the driver will serve its due date. And when self-production observe electrical safety rules and be careful and careful when assembling the circuit.

We hope that the information provided today was useful to our reader. Any questions you may have can be asked in the discussion - we will definitely answer them. Write, ask, share your experience with other readers.

And finally, a short video on today's topic:

LEDs continue to push new frontiers artificial lighting, confirming its superiority with a number of advantages. Much credit for the successful development of LED technology belongs to power supplies. Working in tandem, the driver and LED open up new horizons, guaranteeing the consumer stable brightness and declared lifespan.

What is an LED driver and what functional load is assigned to it? What to look for when choosing and is there an alternative? Let's try to figure it out.

What is an LED driver and what is it for?

Scientifically speaking, LED driver is called electronic device, the main output parameter of which is the stabilized current. It is the current, not the voltage. A voltage stabilized device is commonly referred to as a "power supply" with an indication of the rated output voltage. It is used to power lED strips, modules and LED strips. But it's not about him.

The main electrical parameter of the driver for an LED is the output current, which it can provide for a long time when the appropriate load is connected. Individual LEDs or assemblies based on them act as a load. For a stable glow, it is necessary that the current specified in the passport data flows through the LED crystal. In turn, the voltage on it will drop exactly as much as required. p-n junction at a given current value. The exact values \u200b\u200bof the flowing current and forward voltage drop can be determined from the volt-ampere characteristic (VAC) of the semiconductor device. The driver receives power, as a rule, from a constant 12 V network or a 220 V variable network. Its output voltage is indicated in the form of two extreme values, between which stable operation is guaranteed. Typically, the operating range can be from three volts to several tens of volts. For example, a driver with U out \u003d 9-12 V, I out \u003d 350 mA, as a rule, is designed to daisy-chain three 1 W white LEDs. Each element will drop approximately 3.3 V, which will total 9.9 V, which means it falls within the specified range.

To a stabilizer with a voltage spread at the output of 9-21 V and a current of 780 mA, you can connect from three to six LEDs of 3 W each. Such a driver is considered to be more versatile, but has lower efficiency when switched on with minimal load.

An important parameter of the LED driver is the power that it can deliver to the load. Don't try to get the most out of it. This is especially true for radio amateurs who make series-parallel chains of LEDs with equalizing resistors, and then overload the output transistor of the stabilizer with this self-made matrix.

The electronic part of the LED driver depends on many factors:

• input and output parameters;
• protection class;
• used element base;
• manufacturer.

Modern LED drivers are made using the PWM conversion principle and using specialized microcircuits. Pulse-width converters consist of a pulse transformer and a current stabilization circuit. They are powered from a 220 V network, have high efficiency and short circuit and overload protection.

Single-chip drivers are more compact because they are powered by a low-voltage DC source. They also have high efficiency, but their reliability is lower due to the simplified electronic circuit. Such devices are very much in demand for LED car tuning. As an example, we can call the PT4115 IC, you can read about the finished circuit solution based on this microcircuit in.

Criterias of choice

I would like to note right away that a resistor is not an alternative to a driver for an LED. It will never protect against impulse noise and power surges. Any change in the input voltage will pass through the resistor and lead to an abrupt change in current due to the nonlinearity of the I - V characteristic of the LED. A driver assembled on the basis of a linear stabilizer is also not the best way... Low efficiency severely limits its capabilities.

You need to choose an LED driver only after the number and power of the connected LEDs are known exactly.

Remember! Chips of the same standard size may have different power consumption due to the large number of counterfeits. Therefore, try to purchase LEDs only in trusted stores.

With regards to technical parameters, then on the case of the LED driver it must be indicated:

• power;
• operating range of input voltage;
• operating range of output voltage;
• rated stabilized current;
• degree of protection against moisture and dust.

Open-frame drivers powered by 12 V and 220 V are very attractive. Among them, there are various modifications in which you can connect one or several powerful LEDs... Such devices are convenient for laboratory research and experiments. For home use, you still have to place the product in the case. As a result, monetary savings on an open-type driver board are achieved at the expense of reliability and aesthetics.

In addition to selecting a driver for a LED based on electrical parameters, a potential buyer must clearly understand the conditions for its future operation (location, temperature, humidity). After all, the reliability of the entire system depends on where and how the driver will be installed.

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