From a do-it-yourself cell. Driver for LEDs from an energy-saving lamp. Pulse unit and its purpose

A driver for an LED from an energy-saving lamp can easily be made in an hour if desired.

If you have an old energy-saving lamp lying around, and the electronic ballast in it is working, then you can quite easily make a driver from it to power the LEDs with your own hands. You may have a question, how to check the performance of the ballast? When disassembling the lamp, you need to use a multimeter on the lamp itself, and if at least one of them is burnt, then there is a very high probability that the ballast is in working condition, and if both spirals are intact, then there is probably a malfunction in the ballast parts and it needs to be fixed.

If everything is lying around in a disassembled state, then you just need to very carefully inspect all the parts of the ballast and the tracks of the printed circuit board for damage. Don’t pay attention to the fact that the parts are darkened; they simply work under very harsh temperature conditions. If everything is in order, then you can start assembling the driver for the LEDs. There is no point in checking all the ballast parts, since you will spend a lot of time unsoldering and checking the parts. It will be much faster to assemble a circuit to power the LEDs from energy saving lamp and use it to check the performance of the ballast.

You need to start by soldering jumpers from the wires, as in the photo, and desoldering the inductor. An additional winding of copper wire must be wound onto the inductor.

After you have unsoldered the inductor, you need to disassemble it (disconnect the magnetic circuit) in order to easily wind the wire. First of all, carefully remove the adhesive tape from the surface of the magnetic core and set it aside, since we will still need it for reassembly. We carefully try to separate the halves of the magnetic circuit with our hands (it is very fragile and breaks easily, so do not use much force). If this doesn’t work, then we inspect all the surfaces and, if there are streaks of varnish that glued the magnetic circuit to the coil, then we trim and remove them with a simple stationery knife. Couldn't disconnect? No problem. Next, we heat the magnetic circuit at the connection points using a soldering iron, a hair dryer or a simple lighter (just be careful not to damage the wound wire). When heated, the varnish softens and it will be easier to disconnect the magnetic circuit. It will definitely work out.

Next, you need to lay a layer of electrical insulation on the coil. The wire that is wound on the coil operates under mains voltage and, if you do not isolate it from the future winding, then there is a high probability that the mains voltage will penetrate into the LED power circuit, which is a threat to your life. Insulation can be taken from old chokes, transformers, inductors, as well as wire for winding an additional winding. You can even use paper.

We wind an additional winding. The diameter of the winding wire must be selected based on the number of turns needed to obtain the required voltage and a free window in the magnetic circuit. The maximum possible diameter of the wire is needed (whatever will fit). The thicker the wire, the more power you can get. I have LED assemblies of 24-36 volts at a current of 280-300 milliamps and I wound 30 turns of wire with a diameter of 0.35. It fit with difficulty when wound tightly, but the voltage turned out to be 28 volts. Outputs approximately 1 volt per turn.

We assemble the inductor and solder it in place. To power the LEDs you need D.C., but what we get is impulse. This means you need a rectifier, and if you don’t want to assemble it, you can take a ready-made one, for example from an old power supply, like mine. I draw your attention to the fact that the resulting power supply without a load, in this case the LED, cannot be turned on; it will burn out.

The circuit is assembled and all that remains is to test it.

When measuring the LED current, it turned out to be 290 milliamps at a voltage of 26 volts. Perfect. But the transistors in the ballast get hot. Of course, it’s not scary (they’re used to it), but it’s better to replace them with more powerful ones or install them on radiators if the LED will operate for a long time. I hope now you can make your own power supply from energy-saving lamps for an LED. The resulting device can be used to convert old lamps into LED lamps, if everything is done carefully. I deliberately did everything roughly for clarity and speed of execution.

Good luck to you.

With the development of new technologies, many lighting fixtures have appeared on the shelves of specialty stores, each of which is different. individual characteristics brightness, efficiency and comfort for the eyes.

Making an LED lamp from an energy-saving lamp without soldering

For many years, manufacturers of LED lamps have tried to design a device that is similar in its properties to a conventional incandescent lamp, plus low power consumption, low heat generation and low impact on others. As a result, light bulbs were introduced to consumers.

Experts advise giving preference to the latest models, explaining the choice with a number of obvious advantages. The task becomes more complicated for those who want to learn how to convert an energy-saving device into an LED one with their own hands.

Main differences

LED lamp, one way or another, provides the room with brighter lighting. At a voltage of 13 W, it produces 1000 lm, energy-saving - only 800 lm.

As for heat transfer, it is determined by maintaining the optimal temperature in the building, maintaining it in a suitable condition household appliances and furniture. And here, too, the LED product is in the lead, having a heat dissipation of 30.5 degrees, while the heat dissipation of an energy-saving device is 81.7 degrees.

The latter product is designed for 8,000 hours of active operation, while the first has a record service life of up to 50,000 hours. Moreover, an LED lamp does not lose its original shade of illumination and brightness over time, which cannot be said about an energy-saving lamp.

The laurels of primacy go to LED sources and during the recycling process, they can be thrown into the trash. , thrown into a landfill, pollutes the environment (air and groundwater) with toxic mercury vapor, resulting in severe poisoning of people, animals and fish. That is why it must take place in accordance with certain rules.

Despite the pros and cons, LEDs are interchangeable - manufacturers took care of the appropriate size of any of the lamps and sockets for them.

What the two competing analogues have in common is a fairly high-quality color flow, providing high level comfort for the retina of the human eye.

How to make an LED lamp

Required materials

In order to convert an energy-saving light bulb into an LED light bulb with your own hands, you need to have the following list of materials with you:

  1. A burnt out, broken lamp.
  2. A small piece of fiberglass for connecting parts together. If you have other ideas (besides soldering), you can use yours to solve the question of how to attach the LEDs.
  3. A set of radio elements corresponding to a specific circuit, including LEDs. Experts advise choosing for assembly LED light bulb with your own hands, ordinary parts, which are presented in a large assortment on every radio market, where their cost is significantly lower.
  4. A capacitor with a volume of 0.022 Mf, the voltage in which is 400 V, one resistance is designed for 1 mOhm and a pair of resistances for 200 Ohms.
  5. LEDs are cheaper to solder in the required quantity using a strip.

Making a circuit

The process of creating a circuit with your own hands begins with cutting out a circle with a diameter of 30 mm from PCB. Next, apply paths on the circle; nail polish does a good job of this. After covering one coat, set the piece aside until it is completely dry.

At this time, you can do chemistry, namely, make a mass with your own hands that dissolves copper. To do this, mix copper sulfate and ordinary kitchen salt in a ratio of 1:2. Be sure to add a small amount of warm water (but not hot!) and dip the future board into the resulting mixture. Within a day you will notice how the copper has disappeared from the textolite circle, only the part that was treated with varnish remains.

At the final stage, soldering is performed. However, before moving on to this phase, use a special solvent and get rid of the varnish layer. Then tread the existing paths.

Take a millimeter drill and make holes in the areas where the elements are fixed. Finally, move on to full soldering of the circuit. If you are not new to working with a soldering iron and have certain skills, to create a 220 V LED light bulb with your own hands, or rather, its driver board, you just need to set aside 30 free minutes.

The assembly process is not complete without disassembly. Use a metal saw to cut the perimeter at the very end of the plastic. Take out all the internal parts, leaving only the wires coming from the base of the old lamp. Arm yourself with a soldering iron again and fix the board to these wires.

Attach the circuit equipped with LEDs to inner surface plastic. Before final gluing, turn on the lamp; if it works, use hot glue.

How to do without soldering

Some may not be comfortable with soldering, in which case, as an alternative, the driver for the product is replaced with a full-fledged power supply designed for fixation and operation LED strip. It is due to the use of a whole piece of tape, and not its individual sections, that soldering and global rework are not required.

What problems might arise? With the dimensions of the power supply. Here you will either need to redo the electrical wiring from A to Z (the lighting of the building is reduced to one branch), or power each lamp or row of products with a different transformer. If the house is equipped with spotlights, you can select the very first one from the circuit and place a power supply in front of it, after which, instead of 220 V lamps, install homemade 12 V LED models.

How to assemble light bulbs

Do-it-yourself lighting products are assembled from plastic pipes cut into separate sections. An LED strip is attached to the sides of the pipes using a soldering iron; be sure to check the parallel circuit. At the end of the bundle of wires, place two pins that act as a base.

If the lamps are equipped with a traditional socket for fixing the lamp, the process is simplified significantly - it is enough to modernize old energy-saving devices, and there is no longer a need to use internal boards. As before, the sample is disassembled, and all the “internals”, except the base wires, are removed. The cap from which the fluorescent tubes came out is closed with a cylinder made of plastic, on which sections of the LED strip are fixed. These tapes are connected to the wires from the base.

When connecting, take into account the “+” and “-”. Plus, it is advisable to solder to the lower component of the base. If the connection does not produce results, you can solve the problem by reconnecting the power supply output to the wires.

Conclusion

In any case, there are plenty of ways to switch to more economical lighting. An energy-efficient LED lamp will help save you money, and the process itself will especially appeal to those who have a developed technical mind.

Many thanks to the manufacturers of modern energy-saving lamps. The quality of their products constantly makes us think and pushes us to new technical solutions.
This time we will consider the topic of converting a failed energy-saving lamp into an LED one. Today we'll go the more traditional route using an LED driver, but... The most interesting part of the conversion is the LED itself.
The other day I came across several samples of Chinese electronics industry. These LEDs themselves are interesting, although they do not have outstanding characteristics. But the fact that this LED provides a circular radiation pattern takes it to a whole new level and gives us an excellent tool for modernizing lighting systems.


As a radiator, I used the aluminum universal profile AP888, already known from the previous article, produced by Yug-Service LLC. Unfortunately, I only had a piece of it a little over 10mm thick. There was a fear that the power of 9 W might not be enough for an LED. But the desire to conduct an experiment won out.
A small drawback of this profile in relation to the new LED is that the central hole is 8 mm in diameter, and the thread of the “tail” of the LED is M6.

The easiest way out:
- drill the hole to 10 mm;
- screw the bolt into the M6 ​​nut;
- carefully, hitting the head of the bolt with a hammer, press the nut into the profile. The bolt is needed so as not to accidentally jam the threads in the nut.



LED 7V, power 7-9 W, 12 V, 600-800 mA. As a driver, I used a widely used 700 mA driver for three LEDs from the same Chinese manufacturer.
Then, as always, everything is simple. We know how to disassemble an energy-saving light bulb, the main thing is not to break the bulb. And we prepare the entire kit for assembly.


Is it possible to make an LED lamp operating on 220 volts from start to finish with your own hands? It turns out that it is possible. Our tips and instructions will help you in this exciting activity.

Advantages of LED lamps

LED lighting in the home is not just modern, but also stylish and bright. Conservative fans of incandescent lamps are left with weak “Ilyich light bulbs” - the Federal Law “On Energy Saving”, adopted in 2009, from January 1, 2011 prohibits the production, import and sale of incandescent lamps with a power of more than 100 W. Advanced users have long switched to compact fluorescent lamps (CFLs). But LEDs outperform all their predecessors:

  • the energy consumption of an LED lamp is 10 times less than that of a corresponding incandescent lamp, and almost 35% less than that of a CFL lamp;
  • luminous intensity LED lamps more by 8 and 36%, respectively;
  • reaching full power luminous flux occurs instantly, unlike CFLs, which require about 2 minutes;
  • the cost - provided that the lamp is manufactured independently - tends to zero;
  • LED lamps are environmentally friendly because they do not contain mercury;
  • LED service life is measured in tens of thousands of hours. Therefore, LED lamps are practically eternal.

Dry numbers confirm: LED is the future.

Design of a modern factory LED lamp

The LED here is initially assembled from many crystals. Therefore, in order to assemble such a lamp, you do not need to solder numerous contacts, you only need to connect one pair.

Types of LEDs

LED is a semiconductor multilayer crystal with an electron-hole junction. By passing direct current through it, we receive light radiation. An LED also differs from a conventional diode in that if it is connected incorrectly, it immediately burns out, since it has a low breakdown voltage (several volts). If an LED burns out, it must be completely replaced; repair is impossible.

There are four main types of LEDs:


A homemade and properly assembled LED lamp will serve for many years, and it can be repaired.

Before you begin self-assembly, you need to choose a power supply method for our future lamp. There are many options: from battery to mains AC at 220 volts - through a transformer or directly.

The easiest way is to assemble a 12-volt LED from a burnt-out halogen. But it will require a fairly massive external power supply. A lamp with a regular base, designed for a voltage of 220 volts, fits any socket in the house.

Therefore, in our guide we will not consider creating a 12-volt LED light source, but will show a couple of options for designing a 220-volt lamp.

Since we do not know the level of your electrical technical training, we cannot guarantee that you will end up with a properly functioning device. In addition, you will be working under life-threatening voltage and if things are not done accurately and incorrectly, damage and loss may occur, for which we will not be held responsible. Therefore, be careful and attentive. And you will succeed.

Drivers for LED lamps

The brightness of LEDs directly depends on the strength of the current passing through them. For stable operation, they need a constant voltage source and a stabilized current that does not exceed the maximum permissible value for them.

Resistors - current limiters - can only be used for low-power LEDs. You can simplify the simple calculation of the number and characteristics of resistors by finding an LED calculator on the Internet, which not only displays data, but also creates a ready-made electrical circuit for the design.

To power the lamp from the mains, you must use a special driver that converts the input AC voltage into a working voltage for the LEDs. The simplest drivers consist of minimum quantity parts: an input capacitor, several resistors and a diode bridge.

In the simplest driver circuit, the supply voltage is supplied through a limiting capacitor to the rectifier bridge, and then to the lamp

Powerful LEDs are connected through electronic drivers that control and stabilize the current and have a high efficiency (90-95%). They provide stable current even with sudden changes in the supply voltage in the network. Resistors cannot do this.

Let's look at the simplest and most commonly used drivers for LED lamps:

  • the linear driver is quite simple and is used for low (up to 100 mA) operating currents or in cases where the source voltage is equal to the voltage drop across the LED;
  • The switching buck driver is more complex. He allows you to feed powerful LEDs a source of much higher voltage than is necessary for their operation. Disadvantages: large size and electromagnetic interference generated by the inductor;
  • A switching boost driver is used when the operating voltage of the LED is greater than the voltage received from the power supply. The disadvantages are the same as the previous driver.

An electronic driver is always built into any 220-volt LED lamp to ensure optimal operation.

Most often, several faulty LED lamps are disassembled, the burnt-out LEDs and radio components of the driver are removed, and one new structure is installed from the intact ones.

But you can make an LED lamp from a regular CFL. This is quite attractive idea. We are sure that many zealous owners keep faulty “energy savers” in their drawers with parts and spare parts. It’s a shame to throw it away, there’s nowhere to use it. Now we will tell you how to create an LED lamp from an energy-saving lamp (E27 base, 220 V) in just a couple of hours.

A faulty CFL always gives us a high-quality base and housing for LEDs. In addition, it is usually the gas discharge tube that fails, but not electronic device to “ignite” it. We again put the working electronics in the stash: they can be disassembled, and in capable hands these parts will still serve something good.

Types of modern lamp bases

The base is a threaded system for quickly connecting and fixing the light source and socket, supplying power to the source from the mains and ensuring the tightness of the vacuum flask. The marking of the socles is deciphered as follows:

  1. The first letter of the marking indicates the type of base:
    • B - with pin;
    • E - with thread (developed back in 1909 by Edison);
    • F - with one pin;
    • G - with two pins;
    • H - for xenon;
    • K and R - with cable and recessed contact, respectively;
    • P - focusing base (for spotlights and lanterns);
    • S - soffit;
    • T - telephone;
    • W - with contact inputs in the glass of the bulb.
  2. The second letter U, A or V shows which lamps use the base: energy-saving, automotive or with a conical end.
  3. The numbers following the letters indicate the diameter of the base in millimeters.

The most common base since Soviet times is E27 - a threaded base with a diameter of 27 mm for a voltage of 220 V.

Creating an E27 LED lamp from an energy-saving one using a ready-made driver

To make your own LED lamp we will need:

  1. Failed CFL lamp.
  2. Pliers.
  3. Soldering iron.
  4. Solder.
  5. Cardboard.
  6. Head on shoulders.
  7. Skillful hands.

We will convert the faulty Cosmos CFL to LED.

Step-by-step instructions for making an LED lamp

  1. We find a faulty energy-saving lamp, which we have had for a long time “just in case.” Our lamp has a power of 20 W. For now, the main component we are interested in is the base.
  2. We carefully disassemble old lamp and remove everything from it except the base and the wires coming from it, with which we will then connect the finished driver by soldering. The lamp is assembled using latches protruding above the body. You need to look at them and use something to pry them off. Sometimes the base is attached to the body in a more complicated way - by punching pinholes around the circumference. Here you will have to drill out the core points or carefully saw through them with a hacksaw. One supply wire is soldered to the central contact of the base, the second to the thread. Both of them are very short. The tubes may burst during these manipulations, so you must act carefully.
  3. We clean the base and degrease it with acetone or alcohol. Particular attention should be paid to the hole, which we also carefully clean from excess solder. This is necessary for further soldering in the base.
  4. The cap of the base has six holes - gas-discharge tubes were attached to them. We use these holes for our LEDs. Let's put it under top part a circle of the same diameter cut out with nail scissors from a suitable piece of plastic. Thick cardboard will also work. It will fix the contacts of the LEDs.
  5. We have HK6 multi-chip LEDs (voltage 3.3 V, power 0.33 W, current 100-120 mA). Each diode is assembled from six crystals (connected in parallel), so it shines brightly, although it is not called powerful. Considering the power of these LEDs, we connect them three in parallel.

    Each LED shines quite brightly on its own, so six of them in the lamp will provide good light intensity

  6. We connect both chains in series.

    Two chains of three parallel-connected LEDs are each connected in series

    7. The result is a rather beautiful design.

  7. A simple ready-made driver can be taken from a broken LED lamp. Now, to connect six white one-watt LEDs, we use a 220-volt driver, for example, RLD2-1.

    The driver is connected to the LEDs in a parallel circuit

  8. We insert the driver into the socket. We place another cut-out circle of plastic or cardboard between the board and the driver to avoid short circuits between the LED contacts and the driver parts. The lamp does not heat up, so any gasket will do.
  9. Let's assemble our lamp and check if it works.

We created a source with a luminous intensity of approximately 150-200 lm and a power of approximately 3 W, similar to a 30-watt incandescent lamp. But due to the fact that our lamp has a white glow color, it visually looks brighter. The area of ​​the room illuminated by it can be increased by bending the LED leads. In addition, we received a wonderful bonus: the three-watt lamp does not even need to be turned off - the meter practically does not “see” it.

Creating an LED lamp using a homemade driver

It is much more interesting not to use a ready-made driver, but to make it yourself. Of course, if you are good with a soldering iron and have basic reading skills electrical diagrams.

We'll look at etching the board after drawing the schematic on it by hand. And, of course, everyone will be interested in tinkering with chemical reactions using available chemicals. Like in childhood.

We will need:

  1. A piece of copper foil on both sides of fiberglass.
  2. The elements of our future lamp according to the generated diagram: resistors, capacitor, LEDs.
  3. Drill or mini-drill for drilling fiberglass.
  4. Pliers.
  5. Soldering iron.
  6. Solder and rosin.
  7. Nail polish or correction pencil.
  8. Table salt, copper sulfate or ferric chloride solution.
  9. Head on shoulders.
  10. Skillful hands.
  11. Accuracy and attentiveness.

Textolite is used in cases where electrical insulating properties are required. This is a multilayer plastic, the layers of which consist of fabric (depending on the type of fibers of the fabric layer, there are basalt textolites, carbon textolites, and others) and a binder (polyester resin, bakelite, etc.):

  • Fiberglass is fiberglass fabric impregnated with epoxy resin. It is characterized by high resistivity and heat resistance - from 140 to 1800 o C;
  • foil fiberglass is a material coated with a layer of galvanic copper foil 35-50 microns thick. It is used for making printed circuit boards. The thickness of the composite is from 0.5 to 3 mm, the sheet area is up to 1 m 2.

Driver circuit for LED lamp

It is quite possible to make a driver for an LED lamp yourself, for example, based on the simplest circuit that we looked at at the beginning of the article. You just need to add a few details:

  1. Resistor R3 to discharge the capacitor when the power is turned off.
  2. A pair of zener diodes VD2 and VD3 to bypass the capacitor if the LED circuit burns out or breaks.

If we select the stabilization voltage correctly, we can limit ourselves to one zener diode. If we set the voltage to more than 220 V, and choose a capacitor for it, then we will do without any additional parts at all. But the driver will be larger in size, and the board may not fit in the base.

We created this circuit to make a lamp from 20 LEDs. If there are more or less of them, you need to select a different capacitance for capacitor C1 so that a current of 20 mA still passes through the LEDs.

The driver will lower the network voltage and try to smooth out voltage surges. Through a resistor and a current-limiting capacitor, the mains voltage is supplied to a diode-based bridge rectifier. Through another resistor, a constant voltage is supplied to the LED block, and they begin to shine. The ripples of this rectified voltage are smoothed out by a capacitor, and when the lamp is disconnected from the network, the first capacitor is discharged by another resistor.

It will be more convenient if the driver design is mounted using a printed circuit board, and is not some kind of lump in the air made of wires and parts. You can easily make the payment yourself.

Step-by-step instructions for making an LED lamp with a homemade driver

  1. Using a computer program, we generate our own pattern for etching the board according to the intended driver design. The free computer program Sprint Layout is very convenient and popular among radio amateurs, allowing you to independently design printed circuit boards of low complexity and obtain an image of their layout. There is another excellent domestic program - DipTrace, which draws not only boards, but also circuit diagrams.

    The free computer program Sprint Layout generates detailed diagram Etching the driver board

  2. We cut out a circle with a diameter of 3 cm from fiberglass. This will be our board.
  3. We choose a method for transferring the circuit to the board. All methods are terribly interesting. Can:
    • draw a diagram directly on a piece of fiberglass with a stationery correction pencil or a special marker for printed circuit boards, which is sold in a radio parts store. There is a subtlety here: only this marker allows you to draw tracks less than or equal to 1 mm. In other cases, the width of the track, no matter how hard you try, will not be less than 2 mm. And the copper patches for soldering will turn out sloppy. Therefore, after applying the design, you need to correct it with a razor or scalpel;
    • print the diagram on inkjet printer on photo paper and iron the printout to the fiberglass. The circuit elements will be covered with paint;
    • draw a diagram with nail polish, which is definitely in any house where a woman lives. This is the simplest method, and we will use it. Carefully and carefully, using a brush from a bottle, draw tracks on the board. We wait until the varnish dries well.
  4. We dilute the solution: stir 1 tablespoon of copper sulfate and 2 tablespoons of table salt in boiling water. Copper sulfate is used in agriculture, so it can be bought in gardening and construction stores.
  5. We immerse the board in the solution for half an hour. As a result, only the copper traces that we protected with varnish will remain; the rest of the copper will disappear during the reaction.
  6. Use acetone to remove the remaining varnish from the fiberglass laminate. You immediately need to tin (coat with solder using a soldering iron) the edges of the board and the contact points so that the copper does not quickly oxidize.

    The contact points are soldered with a layer of solder mixed with rosin to protect the copper tracks from oxidation

  7. According to the diagram, we make holes with a drill.
  8. We solder the LEDs and all the details of the homemade driver on the board from the side of the printed tracks.
  9. We install the board into the lamp body.

    After all the operations performed, you should get an LED lamp equivalent to a 100-watt incandescent lamp

Safety Notes

  1. Although self-assembly LED lamp installation is not a very complicated process; you shouldn’t even start it if you don’t have at least basic electrical knowledge. Otherwise, the lamp you assembled with internal short circuit can harm everyone electrical network your home, including expensive electrical appliances. The specificity of LED technology is that if some elements of its circuit are connected incorrectly, then even an explosion is possible. So you have to be extremely careful.
  2. Typically the luminaires are used at 220 VAC. But designs designed for a voltage of 12 V cannot be connected to a regular network under any circumstances, and you must always remember this.
  3. In the process of making a homemade LED lamp, the components of the lamp often cannot be immediately completely isolated from the 220 V power supply. Therefore, you can be seriously shocked. Even if the structure is connected to the network via a power supply, it is quite possible that it has simple diagram without transformer and galvanic isolation. Therefore, you should not touch the structure with your hands until the capacitors are discharged.
  4. If the lamp does not work, then in most cases poor-quality soldering of parts is to blame. You were inattentive or acted hastily with the soldering iron. But don't despair. Keep trying!

Video: learning to solder

It’s a strange thing: in our age, when stores have absolutely everything, usually inexpensive and very varied, after twenty years of euphoria, people are increasingly returning to doing household things with their own hands. Handicrafts, carpentry and plumbing skills flourished beyond belief. And simple applied electrical engineering is confidently returning to this series.

In this article you will find detailed description the process of manufacturing switching power supplies of different powers based on the electronic ballast of a compact fluorescent lamp.
You can make a switching power supply for 5...20 Watts in less than an hour. It will take several hours to make a 100-watt power supply. You can make more powerful electronic transformers, for example on IR2153, or you can BUY READY-made ones and convert them to your own voltages.

Compact Fluorescent Lamps (CFLs) are now widely used. To reduce the size of the ballast choke, they use a high-frequency voltage converter circuit, which can significantly reduce the size of the choke.

If the electronic ballast fails, it can be easily repaired. But when the bulb itself fails, the light bulb is usually thrown away.

However, the electronic ballast of such a light bulb is an almost ready-made switching power supply unit (PSU), and quite compact. The only way the electronic ballast circuit differs from a real switching power supply is the absence of an isolation transformer and a rectifier, if necessary.

At the same time, modern radio amateurs experience great difficulties when finding power transformers to power their homemade products. Even if a transformer is found, then rewinding it requires the use large quantity copper wire, and the weight-dimensional parameters of products assembled on the basis of power transformers are not encouraging. But in the vast majority of cases, the power transformer can be replaced with a switching power supply. If for these purposes you use ballast from faulty energy-saving lamps, the savings will be a significant amount, especially if we are talking about transformers of 100 watts or more.

The difference between the ballast circuit of an energy-saving lamp and a switching power supply

This is one of the most common electrical circuits for energy-saving lamps. To convert a CFL circuit into a switching power supply, it is enough to install just one jumper between points A – A’ and add a pulse transformer with a rectifier. Elements that can be deleted are marked in red.


Energy saving lamp circuit

And this is a complete circuit of a switching power supply, assembled on the basis of a fluorescent lamp ballast using an additional pulse transformer.

To simplify, the fluorescent lamp and several parts were removed and replaced with a jumper.

As you can see, the CFL circuit does not require major changes. Additional elements introduced into the scheme are marked in red.


Complete switching power supply circuit

What power power supply can be made from CFLs?

The power of a switching power supply is limited by the overall power of the pulse transformer, the maximum permissible current of the key transistors and the size of the cooling radiator, if used.

A small power supply can be built by winding the secondary winding directly onto the frame of an existing inductor.


PSU with a secondary winding directly onto the frame of an existing inductor

If the choke window does not allow winding the secondary winding or if it is necessary to build a power supply with a power significantly exceeding the power of the CFL, then an additional pulse transformer will be needed.


PSU with additional pulse transformer

If you need to get a power supply with a power of over 100 Watt, and you are using a ballast from a 20-30 Watt lamp, then, most likely, you will have to make small changes to the electronic ballast circuit.

In particular, you may need to install more powerful diodes VD1-VD4 in the input bridge rectifier and rewind the input inductor L0 with a thicker wire. If the current gain of the transistors turns out to be insufficient, then you will have to increase the base current of the transistors by reducing the values ​​of resistors R5, R6. In addition, you will have to increase the power of resistors in the base and emitter circuits.

If the generation frequency is not very high, then it may be necessary to increase the capacitance of the isolation capacitors C4, C6.

Pulse transformer for power supply

A feature of half-bridge switching power supplies with self-excitation is the ability to adapt to the parameters of the transformer used. And the fact that the feedback circuit will not pass through our homemade transformer completely simplifies the task of calculating the transformer and setting up the unit. Power supplies assembled according to these schemes forgive errors in calculations of up to 150% or more. Tested in practice.

Don't be scared! You can wind a pulse transformer within the course of watching one movie, or even faster if you are going to do this monotonous work with concentration.

Input filter capacitance and voltage ripple

In the input filters of electronic ballasts, to save space, small capacitors are used, on which the magnitude of voltage ripple with a frequency of 100 Hz depends.

To reduce the level of voltage ripple at the output of the power supply, you need to increase the capacitance of the input filter capacitor. It is advisable that for every watt of PSU power there is one microfarad or so. An increase in capacitance C0 will entail an increase in the peak current flowing through the rectifier diodes at the moment the power supply is turned on. To limit this current, a resistor R0 is needed. But, the power of the original CFL resistor is small for such currents and it should be replaced with a more powerful one.

If you need to build a compact power supply, you can use electrolytic capacitors, which are used in film flash lamps. For example, in disposable cameras Kodak installed miniature capacitors without identification marks, but their capacity is as much as 100µF at a voltage of 350 Volts.

20 Watt power supply


20 Watt power supply

A power supply with a power close to the power of the original CFL can be assembled without even winding a separate transformer. If the original inductor has enough free space in the magnetic circuit window, then you can wind a couple of dozen turns of wire and get, for example, a power supply for charger or a small power amplifier.

The picture shows that one layer of insulated wire was wound over the existing winding. I used MGTF wire (stranded wire in fluoroplastic insulation). However, in this way you can get a power of only a few watts, since most of the window will be occupied by the wire insulation, and the cross-section of the copper itself will be small.

If more power is required, then ordinary varnished copper winding wire can be used.

Attention! The original inductor winding is under mains voltage! When making the modification described above, be sure to take care of reliable inter-winding insulation, especially if the secondary winding is wound with ordinary varnished winding wire. Even if the primary winding is covered with a synthetic protective film, an additional paper gasket is necessary!

As you can see, the winding of the inductor is covered with a synthetic film, although often the winding of these chokes is not protected at all.

We wrap two layers of electrical cardboard 0.05 mm thick or one layer 0.1 mm thick over the film. If there is no electrical cardboard, we use any paper of suitable thickness.

We wind the secondary winding of the future transformer on top of the insulating gasket. The wire cross-section should be selected as large as possible. The number of turns is selected experimentally, fortunately there will be few of them.

Thus, I managed to obtain power at a load of 20 Watts at a transformer temperature of 60°C, and a transistor temperature of 42°C. It was not possible to obtain even more power at a reasonable temperature of the transformer due to the too small area of ​​the magnetic circuit window and the resulting wire cross-section.


The picture shows the current PSU model

The power supplied to the load is 20 watts.
The frequency of self-oscillations without load is 26 kHz.
Self-oscillation frequency at maximum load – 32 kHz
Transformer temperature – 60? C
Transistor temperature – 42? C

100 Watt power supply

To increase the power of the power supply, we had to wind the TV2 pulse transformer. In addition, I increased the capacitance of the mains voltage filter capacitor C0 to 100µF.


100 Watt power supply

Since the efficiency of the power supply is not 100%, we had to attach some radiators to the transistors.

After all, if the efficiency of the unit is even 90%, you will still have to dissipate 10 Watts of power.

I was unlucky; my electronic ballast was equipped with transistors 13003 pos. 1 of a design that was apparently designed to be attached to a radiator using shaped springs. These transistors do not require spacers, since they are not equipped with a metal platform, but they also dissipate heat much worse. I replaced them with transistors 13007 pos. 2 with holes so that they could be screwed to the radiators with ordinary screws. In addition, 13007 have several times higher maximum permissible currents. You can buy MJE13007 separately.

If you wish, you can safely screw both transistors onto one radiator. I checked it works.

Only, the housings of both transistors must be insulated from the radiator housing, even if the radiator is located inside the electronic device housing.

It is convenient to fasten with M2.5 screws, onto which you must first put insulating washers and sections of an insulating tube (cambric). It is allowed to use heat-conducting paste KPT-8, since it does not conduct current.

Attention! Transistors are under mains voltage, so insulating gaskets must ensure electrical safety conditions!


Operating 100-watt switching power supply

The load equivalent resistors are placed in water because their power is insufficient.
The power released at the load is 100 watts.
The frequency of self-oscillations at maximum load is 90 kHz.
The frequency of self-oscillations without load is 28.5 kHz.
Transistor temperature – 75?C.
The area of ​​the radiators of each transistor is 27 cm?.
Throttle temperature TV1 – 45?C.
TV2 – 2000NM (O28 x O16 x 9mm)

Rectifier

All secondary rectifiers of a half-bridge switching power supply must be full-wave. If this condition is not met, the magnetic pipeline may become saturated.

There are two widely used full-wave rectifier designs.

1. Bridge circuit.
2. Circuit with zero point.

The bridge circuit saves a meter of wire, but dissipates twice as much energy on the diodes.

The zero-point circuit is more economical, but requires two perfectly symmetrical secondary windings. Asymmetry in the number of turns or location can lead to saturation of the magnetic circuit.

However, it is precisely zero-point circuits that are used when it is necessary to obtain high currents at a low output voltage. Then, to further minimize losses, instead of conventional silicon diodes, Schottky diodes are used, on which the voltage drop is two to three times less.

Example.
The rectifiers of computer power supplies are made according to a zero-point circuit. With a power supplied to the load of 100 Watts and a voltage of 5 Volts, even Schottky diodes can dissipate 8 Watts.

100 / 5 * 0.4 = 8(Watt)

If you use a bridge rectifier, and even ordinary diodes, then the power dissipated by the diodes can reach 32 Watts or even more.

100 / 5 * 0.8 * 2 = 32(Watt).

Pay attention to this when you design a power supply so that you don’t have to look for where half the power disappeared.

In low-voltage rectifiers it is better to use a circuit with a zero point. Moreover, with manual winding, you can simply wind the winding in two wires. In addition, high-power pulse diodes are not cheap.

How to properly connect a switching power supply to the network?

To set up switching power supplies, the following connection circuit is usually used. Here, an incandescent lamp is used as a ballast with a nonlinear characteristic and protects the UPS from failure in emergency situations. The lamp power is usually chosen close to the power of the switching power supply being tested.

When the switching power supply is operating at idle or at light load, the resistance of the lamp filament is small and it does not affect the operation of the unit. When, for some reason, the current of the key transistors increases, the lamp coil heats up and its resistance increases, which leads to the current being limited to a safe value.

This drawing shows a diagram of a stand for testing and setting up pulsed power supplies that meets electrical safety standards. The difference between this circuit and the previous one is that it is equipped with an isolation transformer, which provides galvanic isolation of the UPS under study from the lighting network. Switch SA2 allows you to block the lamp when the power supply produces high power.

An important operation when testing a power supply is testing on an equivalent load. It is convenient to use powerful resistors such as PEV, PPB, PSB, etc. as a load. These “glass-ceramic” resistors are easy to find on the radio market by their green coloring. Red numbers are power dissipation.

We know from experience that for some reason there is always not enough power equivalent to the load. The resistors listed above can, for a limited time, dissipate power two to three times higher than the rated power. When the power supply is turned on for a long time to check the thermal conditions, and the equivalent load power is insufficient, the resistors can simply be lowered into water.

Be careful, beware of burns!
Load resistors of this type can heat up to temperatures of several hundred degrees without any external manifestations!
That is, you will not notice any smoke or change in color and you can try to touch the resistor with your fingers.

How to set up a switching power supply?

Actually, a power supply assembled on the basis of a working electronic ballast does not require any special adjustment.

It needs to be connected to the equivalent load and make sure that the power supply is capable of delivering the calculated power.

During a run under maximum load, you need to monitor the dynamics of the temperature rise of the transistors and transformer. If the transformer heats up too much, then you need to either increase the cross-section of the wire, or increase the overall power of the magnetic circuit, or both.

If the transistors get very hot, you need to install them on radiators.

If a home-wound inductor from a CFL is used as a pulse transformer, and its temperature exceeds 60... 65? C, then the load power must be reduced.

SWITCH POWER SUPPLY FROM ENERGY SAVING LAMPS DIY low-power switching power supply made from scrap materials

What is the purpose of the switching power supply circuit elements?


Switching power supply circuit

R0 – limits the peak current flowing through the rectifier diodes at the moment of switching on. In CFLs it also often serves as a fuse.

VD1… VD4 – bridge rectifier.

L0, C0 – power filter.

R1, C1, VD2, VD8 – converter starting circuit.

The launch node works as follows. Capacitor C1 is charged from the source through resistor R1. When the voltage on capacitor C1 reaches the breakdown voltage of dinistor VD2, the dinistor unlocks itself and unlocks transistor VT2, causing self-oscillations. After generation occurs, rectangular pulses are applied to the cathode of the diode VD8 and the negative potential reliably locks the dinistor VD2.

R2, C11, C8 – make it easier to start the converter.

R7, R8 – improve transistor blocking.

R5, R6 – limit the base current of the transistors.

R3, R4 – prevent saturation of transistors and act as fuses in case of breakdown of transistors.

VD7, VD6 – protect transistors from reverse voltage.

TV1 – feedback transformer.

L5 – ballast choke.

C4, C6 are decoupling capacitors on which the supply voltage is divided in half.

TV2 – pulse transformer.

VD14, VD15 – pulse diodes.

C9, C10 – filter capacitors.

Based on materials from the site http://www.ruqrz.com/

For greater clarity, here are several schematic diagrams of lamps from popular manufacturers:

The range of modern stores is very large. Every day new items appear. This also applies to lighting devices, which are becoming more advanced. The main differences between them are brightness, economic characteristics and the creation of the necessary comfort for the eyes.

Most manufacturers have tried to create a product similar to a conventional incandescent lamp, only with more advanced functions. Which will reduce the need for electricity, while reducing the degree of heating and impact on the environment. Therefore, the world saw a new type of LED and energy-saving lamps, which are in no way inferior to the characteristics of standard products and have a number of advantages.

Many craftsmen are trying to create a power supply from. After all, the cost of some products is significantly inflated. And to make a power supply with your own hands you won’t need a lot of time and money.

How to make a power supply from an energy-saving lamp

It is quite simple to create a switching power supply from an energy-saving lamp. It is enough to have the basic knowledge that we will need in the process of creating this product.

In order to create you will need the following materials:

  • Old lamp. A burnt out, non-working lamp will do.
  • Fiberglass for joining parts. There are other options for attaching LEDs without soldering. You can use any other option known to you.
  • All the necessary elements that are in a special circuit, which necessarily contain LEDs. In order to save as much as possible, you can use any available means. It is also better to buy them on the radio components market, where prices are more affordable than in the store.
  • Capacitors of the required volumes, which are suitable for a maximum voltage of 400 volts.
  • Required number of LEDs.
  • Glue for fixing the product.

What kind of lamp do we need?

A power supply made from the ballast of energy-saving lamps is an excellent option for creating a cheap and quality lighting with your own hands, without much expense. This way you can replace all the lamps in your home.

To create a power supply from an energy-saving lamp with your own hands, you first need to cut a circle from PCB to the size of the product. Then you need to draw round stripes on this shape. To do this, you can use any available means that you have on the farm. In this matter, the accuracy and evenness of the lines is important. After all, LEDs will be attached according to this scheme. While the product is drying, you can prepare other necessary parts to create a power supply. This includes soldering all the necessary parts, drilling holes with a drill that are needed for fastening, and fastening all the elements together. All parts are attached with a special adhesive that is resistant to different temperatures.

In order to create a power supply from an energy-saving lamp you will not need much time. The procedure itself will not take more than an hour. At the same time, you can get a high-quality product that will help you save on electricity.

There are also many other ways to create a power supply from an energy-saving one, which are completely accessible and within the power of almost everyone.

Energy-saving light bulbs are widely used for both domestic and industrial purposes. Over time, any lamp becomes faulty. However, if desired, the lamp can be revived by assembling a power supply from an energy-saving lamp. In this case, the filling of a failed light bulb is used as components of the block.

Pulse block and its purpose

At both ends of the fluorescent lamp tube there are electrodes, an anode and a cathode. Applying power causes the lamp components to heat up. After heating, electrons are released, which collide with mercury molecules. The consequence of this is ultraviolet radiation.

Due to the presence of phosphor in the tube, the phosphor is converted into the visible glow of the light bulb. The light does not appear immediately, but after a certain period of time after connecting to the power supply. The more worn out the lamp is, the longer the interval.

The operation of a switching power supply is based on the following principles:

  1. Converting alternating current from the electrical network to direct current. In this case, the voltage does not change (that is, it remains 220 V).
  2. Transformation of DC voltage into rectangular pulses due to the operation of a width pulse converter. The pulse frequency ranges from 20 to 40 kHz.
  3. Supplying voltage to the lamp via a choke.

An uninterruptible power supply (UPS) consists of a number of components, each of which has its own marking in the diagram:

  1. R0 - plays a limiting and protective role in the power supply. The device prevents and stabilizes excessive current flowing through the diodes at the time of connection.
  2. VD1, VD2, VD3, VD4 - act as bridge rectifiers.
  3. L0, C0 - are transmission filters electric current and protect against voltage surges.
  4. R1, C1, VD8 and VD2 - represent a chain of converters used during startup. The first resistor (R1) is used to charge capacitor C1. As soon as the capacitor breaks through the dinistor (VD2), it and the transistor open, resulting in self-oscillation in the circuit. Next square pulse sent to the diode cathode (VD8). A negative indicator appears, covering the second dinistor.
  5. R2, C11, C8 - facilitate the start of operation of the converters.
  6. R7, R8 - optimize the closing of transistors.
  7. R6, R5 - form boundaries for electric current on transistors.
  8. R4, R3 - are used as fuses during voltage surges in transistors.
  9. VD7 VD6 - protect power supply transistors from return current.
  10. TV1 is a reverse communication transformer.
  11. L5 - ballast choke.
  12. C4, C6 - act as isolation capacitors. Divide all the tension into two parts.
  13. TV2 is a pulse type transformer.
  14. VD14, VD15 - pulse diodes.
  15. C9, C10 - filter capacitors.

Pay attention! In the diagram below, the components that need to be removed when remaking the block are marked in red. Points A-A are connected by a jumper.

Only a thoughtful selection of individual elements and their correct installation will allow you to create an efficiently and reliably operating power supply.

Differences between a lamp and a pulse unit

The circuit of the energy-saving lamp is in many ways similar to the structure of a switching power supply. That is why it is not difficult to make a switching power supply. To remake the device, you will need a jumper and an additional transformer that will produce pulses. The transformer must have a rectifier.

To make the power supply lighter, the glass fluorescent bulb is removed. The power parameter is limited to the highest throughput transistors and sizes of cooling elements. To increase power, it is necessary to wind additional winding on the inductor.

Modification of the block

Before you start remaking the power supply, you need to select the current output power. The degree of modernization of the system depends on this indicator. If the power is in the range of 20-30 W, there will be no need for deep changes in the circuit. If the planned power is more than 50 W, a more systematic upgrade is needed.

Pay attention! There will be a constant voltage at the output of the power supply. It is not possible to obtain an alternating voltage at a frequency of 50 Hz.

Power determination

Power is calculated according to the formula:

As an example, consider the situation with a power supply having the following characteristics:

  • voltage - 12 V;
  • current strength - 2 A.

We calculate the power:

P = 2 × 12 = 24 W.

The final power parameter will be higher - approximately 26 W, which allows you to take into account possible overloads. Thus, to create a power supply, a fairly minor intervention in the circuit of a standard 25 W economy lamp will be required.

New components

New electronic components include:

  • diode bridge VD14-VD17;
  • 2 capacitors C9 and C10;
  • winding on the ballast choke (L5), the number of turns of which is determined empirically.

An additional winding performs another important function- is a separating transformer and protects against voltage penetration to the UPS outputs.

To calculate the required number of turns in the additional winding, perform the following steps:

  1. Temporarily apply a winding to the inductor (approximately 10 turns of wire).
  2. We connect the winding to the load resistance (power from 30 W and resistance 5-6 Ohms).
  3. We connect to the network and measure the voltage at the load resistance.
  4. We divide the result obtained by the number of turns and find out how many volts there are for each turn.
  5. We find out the required number of turns for a permanent winding.

The calculation procedure is shown in more detail below.

To calculate the required number of turns, divide the planned voltage for the block by the voltage of one turn. The result is the number of turns. It is recommended to add 5-10% to the final result, which will allow you to have a certain margin.

Do not forget that the original inductor winding is under mains voltage. If you need to wind a new layer of winding on it, take care of the inter-winding insulating layer. It is especially important to observe this rule when PEL type wire in enamel insulation is applied. Polytetrafluoroethylene tape (0.2 mm thick) is suitable as an interwinding insulating layer, which will increase the density threaded connections. This type of tape is used by plumbers.

Pay attention! The power in the block is limited by the overall power of the transformer involved, as well as the maximum possible current of the transistors.

Making your own power supply

You can make a UPS yourself. This will require minor modifications to the electronic throttle jumper. Next, the connection is made to the pulse transformer and rectifier. Individual elements of the scheme are removed due to their unnecessary use.

If the power supply is not too high-power (up to 20 W), it is not necessary to install a transformer. A few turns of conductor wound around a magnetic circuit located on the ballast of the light bulb is enough. However, this operation can only be carried out if there is sufficient space for the winding. For example, a conductor of the MGTF type with a fluoroplastic insulating layer is suitable for it.

Usually not much wire is needed, since almost the entire lumen of the magnetic circuit is given over to the insulation. It is this factor that limits the power of such blocks. To increase power you will need a pulse type transformer.

A distinctive characteristic of this type of SMPS (switching power supply) is the ability to adapt it to the characteristics of the transformer. In addition, the system does not have a feedback loop. The connection diagram is such that there is no need for particularly accurate calculations of the transformer parameters. Even if a gross error is made in the calculations, the uninterruptible power supply will most likely function.

A pulse transformer is created on the basis of a choke, on which a secondary winding is superimposed. As such, varnished copper wire is used.

The interwinding insulating layer is most often made of paper. In some cases, a synthetic film is applied to the winding. However, even in this case, you should additionally protect yourself and wrap 3-4 layers of special electrical protective cardboard. As a last resort, paper with a thickness of 0.1 millimeter or more is used. Copper wire is applied only after this safety measure has been provided.

As for the diameter of the conductor, it should be as large as possible. The number of turns in the secondary winding is small, so the appropriate diameter is usually selected by trial and error.

Rectifier

To prevent saturation of the magnetic circuit in the uninterruptible power supply, only full-wave output rectifiers are used. For a pulse transformer operating to reduce voltage, a circuit with a zero mark is considered optimal. However, for it it is necessary to make two absolutely symmetrical secondary windings.

For a switching uninterruptible power supply, a conventional rectifier operating according to a diode bridge circuit (using silicon diodes) is not suitable. The fact is that for every 100 W of transported power, the losses will be at least 32 W. If you make a rectifier from powerful pulsed diodes, the costs will be high.

Setting up an uninterruptible power supply

When the power supply is assembled, all that remains is to connect it to heaviest load to check whether the transistors and transformer are overheating. The maximum temperature for the transformer is 65 degrees, and for transistors - 40 degrees. If the transformer heats up too much, you need to take a conductor with a larger cross-section or increase the overall power of the magnetic circuit.

The above actions can be performed simultaneously. For transformers made from choke balances, it will most likely not be possible to increase the cross-section of the conductor. In this case, the only option is to reduce the load.

High Power UPS

In some cases, the standard ballast power is not enough. As an example, let's take the following situation: you have a 24 W lamp and you need a UPS for charging with characteristics of 12 V/8 A.

To implement the scheme, you will need an unused computer power supply. From the block we take out the power transformer along with the R4C8 circuit. This circuit protects the power transistors from excessive voltage. We connect the power transformer to electronic ballast. In this situation, the transformer replaces the inductor. Below is a diagram for assembling an uninterruptible power supply based on an energy-saving light bulb.

It is known from practice that this type of block makes it possible to receive up to 45 W of power. The heating of the transistors is within the normal range, not exceeding 50 degrees. To completely eliminate overheating, it is recommended to install a transformer with a large core cross-section into the transistor bases. Transistors are placed directly on the radiator.

Potential Bugs

There is no point in simplifying the circuit by applying the base windings directly to the power transformer. If there is no load, considerable losses will occur, since a large current will flow into the transistor bases.

If a transformer is used with an increase in load current, the current in the transistor bases will also increase. It has been empirically established that after the load reaches 75 W, saturation occurs in the magnetic circuit. The result of this is a decrease in the quality of the transistors and their excessive heating. To prevent such developments, it is recommended to wind the transformer yourself using a larger core cross-section. It is also possible to fold two rings together. Another option is to use a larger conductor diameter.

The base transformer, which acts as an intermediate link, can be removed from the circuit. For this purpose, the current transformer is connected to a dedicated winding of the power transformer. This is done using a high-power resistor based on a feedback circuit. The disadvantage of this approach is the constant operation of the current transformer under saturation conditions.

It is unacceptable to connect the transformer together with the choke (located in the ballast converter). Otherwise, due to the decrease in overall inductance, the frequency of the UPS will increase. The consequence of this will be losses in the transformer and excessive heating of the rectifier transistor at the output.

We must not forget about the high responsiveness of diodes to increased reverse voltage and current. For example, if you put a 6-volt diode in a 12-volt circuit, this element will quickly become unusable.

Transistors and diodes should not be replaced with low-quality electronic components. Operating characteristics of the element base Russian production leave much to be desired, and the result of replacement will be a decrease in the functionality of the uninterruptible power supply.