While visiting the sites of foreign DIYers, I noticed that so-called life hacking is very popular there. This literally translates as “hacking of life.” Don’t think anything bad, life hacking has nothing to do with computer hacking! That's just what they call it useful tips, which help people use seemingly completely unnecessary things - empty cans, PET bottles, burnt out light bulbs that have disabled Appliances. They are not thrown away, but simply change their role or are used as spare parts for other useful devices. I would like to offer something similar.
Energy-saving lamps are gaining popularity. The European Union generally already prohibits the production of conventional incandescent lamps. But unfortunately, energy saving lamps also sometimes fail. You can, of course, throw them away and forget about them. Or you can subject it to hacking. So, let's figure it out a burnt-out energy-saving lamp to try to reuse it. Because, as a rule, only the filaments in the bulb itself burn out, and the electronic components in the lamp base are operational with a probability of 99.9%.

To see what color the insides are energy saving lamp, it needs to be opened. To avoid injuring your hands on the glass tubes (they are made of thin glass and can burst at any moment), wrap the flask in a plastic bag and secure it with tape. The place where the body is glued is obvious and we are trying to separate its parts using a screwdriver or a powerful knife. If you do this carefully, it will take about 2 minutes.

When Powersave lamp will fall into three parts, the following picture will open to us

As you can see, the main parts are flask, a board with electronic elements (radio components) and a lamp base. Now let's figure out what and how we can apply.

Energy saving lamp bulb. To be honest, I haven’t figured out what to do with it yet. The flask is a sealed glass shell coated on the inside with a phosphor. It is unlikely that it will be possible to open it painlessly. But using it as some kind of float is unreliable - it’s glass after all.

Base. This item is already more attractive. It can be given a second life. After all, this is actually a small case, with a contact that can be screwed into any standard E27 or E14 socket.

The simplest application is from this plinth you can make an extension cord (low-power, of course). Only it will be possible to plug it into any socket rather than into a socket. Perhaps the oldest generation remembers such devices. For some reason they were called “rogue”. This is a kind of “lamp-socket” adapter. By the way, it can be very useful in our time. Especially when traveling abroad. Since the design system of sockets may be unique and original in the country, it is not always possible to purchase or select an adapter for it, but you need to charge a mobile phone, laptop, navigator, or camera.

I personally once found myself in such a situation while vacationing in the Maldives. That time, my ingenuity and the fact that I am, after all, an electronics engineer helped me out. But some of my fellow tribesmen struggled with exercises until I told them.

At the same time, if they had such a “rogue”, there would be no problems! All over the world there are only 2 lamp standards (base) - 27 and 14 mm base. And you can connect to the power grid with a set of two such adapters even in Africa.

Other uses plinth- make an LED night light out of it. If you take powerful lighting LEDs and match them with a damping resistance, they can be connected to a 220-volt network. You can cover everything with some small translucent toy or just a piece of plexiglass. So the LED emergency lamp or night light for the child is ready. And you can screw it into a regular table lamp or sconce. Or you can provide lighting in some technical room. After all, such a lamp will consume 1-2 W at most.
You can make an adapter from E27 to E14 (minion), and if you are good with electronics, you can assemble some other electronic device in the base.

Electronic board of energy-saving lamp. In fact, it is a power supply - a converter, and a high-frequency one at that.

Let's take a closer look at what's interesting on this board. So:

Diodes - 6 pcs. High-voltage ones (220 Volts) hold up, although obviously they are low-power (hardly more than 0.5 Amperes). But for a diode rectifier bridge they will do just fine.

Throttle. The thing is useful in principle, but not very much. It removes network interference where it exists.

Medium power transistors (2 Watts each). Great thing, give it a bold +.

High voltage electrolyte. The capacity, although small (4.7 uF), is 400 volts. Plus.

Regular capacitors for different capacities, but all for 250 volts. Plus.

Two high-frequency transformers with unknown parameters. It is still unknown where to apply it; the thing is not at all universal (except for the core).

Several resistors (the value is unknown, you need to either test them with an ohmmeter or decipher the color marks on them). Plus.

What can be made from this very small pile of parts? In fact, quite a lot of things. There are many circuits of useful devices “on one transistor” in the literal sense of the word. From all kinds of watchdog devices, signaling devices, temperature controllers and timers, etc., etc., etc. And we have two whole transistors!

In custody advantages and disadvantages of energy saving lamps

Advantages of energy saving lamps
Energy saving. The efficiency of an energy-saving lamp is very high and the luminous efficiency is approximately 5 times greater than that of a traditional incandescent light bulb. For example, a 20 W energy-saving light bulb produces a luminous flux equal to that of a conventional 100 W incandescent lamp. Thanks to this ratio, energy-saving lamps allow you to save 80% without losing the room illumination that you are used to. Moreover, during long-term operation from a conventional incandescent light bulb, the luminous flux decreases over time due to the burnout of the tungsten filament, and it illuminates the room worse, while energy-saving lamps do not have such a drawback.

Long service life. Compared to traditional incandescent lamps, energy-saving lamps last several times longer. Conventional incandescent light bulbs fail due to the tungsten filament burning out. Energy-saving lamps, having a different design and a fundamentally different operating principle, last much longer than incandescent lamps, on average 5-15 times. This is approximately from 5 to 12 thousand hours of lamp operation (usually the lamp operating life is determined by the manufacturer and indicated on the packaging). Due to the fact that energy-saving lamps last a long time and do not require frequent replacement, they are very convenient to use in places where the process of replacing light bulbs is difficult, for example, in rooms with high ceilings or in chandeliers with complex structures, where to replace the light bulb you have to disassemble the body of the chandelier itself .

Low heat transfer. Due to the high efficiency of energy-saving lamps, all expended electricity is converted into luminous flux, while energy-saving lamps emit very little heat. In some chandeliers and lamps, it is dangerous to use conventional incandescent light bulbs, because they release large amounts of heat and can melt the plastic part of the socket, adjacent wires or the housing itself, which in turn can lead to a fire. Therefore, energy-saving lamps simply must be used in lamps, chandeliers and sconces with limited temperature levels.

Great light output. In a conventional incandescent lamp, light comes only from a tungsten filament. The energy-saving lamp glows over its entire area. Thanks to this, the light from the energy-saving lamp is soft and uniform, more pleasing to the eye and better distributed throughout the room.

Selecting the desired color. Thanks to different shades of phosphor covering the body of the light bulb, energy-saving lamps have different colors of luminous flux, it can be soft white light, cool white, daylight, etc.;

Disadvantages of energy-saving lamps
The only and significant disadvantage of energy-saving lamps compared to traditional incandescent lamps is their high price. The price of an energy-saving light bulb is 10-20 times more than a regular incandescent light bulb. But an energy-saving light bulb is called energy-saving for a reason. Considering the energy savings when using these lamps and their service life, in the end, the use of energy-saving lamps will be more profitable for you and your budget.

There is one more feature use of energy-saving lamps, which must be attributed to their disadvantage. An energy-saving lamp is filled with mercury vapor inside. Mercury is considered a dangerous poison. Therefore, it is very dangerous to break such lamps in an apartment or room. You should be very careful when handling them. For the same reason, energy-saving lamps can be classified as environmentally harmful, and therefore they require special disposal, and throwing away such lamps is, in fact, prohibited. But for some reason, when selling energy-saving lamps in a store, sellers do not explain where to put them next.

That's why, reusing faulty lamps, we also save the environment from harmful effects.

Technical information: → Make a power supply from a burnt-out energy-saving lamp

This publication contains material for repairing or 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 a short time. It can take up to several hours to make a 100-watt power supply.

It will not be difficult to build a power supply if you know how to solder. And undoubtedly, this is not difficult to do than to find a low-frequency transformer suitable for manufacturing of the required power and rewind its secondary windings to the required voltage.

IN Lately Compact Fluorescent Lamps (CFLs) have become widespread. 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 has to be thrown away.

However, the electronic ballast of such a light bulb is an almost ready-made switching power supply unit (PSU). 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.

Recently, radio amateurs sometimes have difficulty finding power transformers to power their homemade designs. Even if a transformer is found, then its rewinding requires the use of copper wires of the required diameter, and the weight and dimensional parameters of products assembled on the basis of power transformers are not particularly encouraging. But in the vast majority of cases, the power transformer can be replaced with a switching power supply. If you use ballast from faulty CFLs for these purposes, the savings will amount to a certain amount, especially if we are talking about transformers of 100 watts or more.

The difference between a CFL circuit and a pulse power supply.

This is one of the most common electrical diagrams energy saving lamps. To convert a CFL circuit into a switching power supply, you need 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.

And this is a completed scheme pulse block power supply, assembled on the basis of CFLs 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.

What power power supply can be made from CFLs?

The power of the 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 when using it.

A low-power power supply can be built by winding the secondary winding directly onto the frame of an existing inductor from the lamp block.

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.

If you need to get a power supply with a power of over 100 Watts, 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.

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

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 need gaskets, since they are not equipped with a metal platform, but they also transfer 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.
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!

The drawing shows a sectional view of the connection of the transistor to the cooling radiator.

1. Screw M2.5.
2. Washer M2.5.
3. Insulating washer M2.5 – fiberglass, textolite, getinax.
4. Transistor housing.
5. The gasket is a piece of tube (cambric).
6. Gasket – mica, ceramics, fluoroplastic, etc.
7. Cooling radiator.

And this is a working 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 – 75ºC.
The area of ​​the radiators of each transistor is 27 cm².
Throttle temperature TV1 – 45ºC.
TV2 – 2000NM (Ø28 x Ø16 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.
Computer power supply rectifiers are designed according to a zero-point circuit. With a power delivered 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 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 supplies more power.

And this is an image of a real stand for repairing and setting up switching power supplies, which I made many years ago according to the diagram located above.

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.

It is known from experience that for some reason there is always not enough power equivalent to the load. The resistors listed above can limited time dissipate two to three times 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 load equivalent and make sure that the power supply is capable of delivering the calculated power.
While running under maximum load, you need to monitor the dynamics of temperature growth of 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... 65ºС, then the load power must be reduced.
It is not recommended to raise the temperature of the transformer above 60... 65ºС, and of transistors above 80... 85ºС.

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

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.

I bought 10 W 900 lm warm white LEDs on AliExpress to try. The price in November 2015 was 23 rubles per piece. The order arrived in a standard bag, I checked everything was in good order.


To power LEDs in lighting devices, special units are used - electronic drivers, which are converters that stabilize the current rather than the voltage at their output. But since the drivers for them (I also ordered on AliExpreess) were still on the way, I decided to power them from ballast from energy-saving lamps. I've had several of these faulty lamps. whose filament in the bulb burned out. As a rule, the voltage converter for such lamps is working properly, and it can be used as a switching power supply or LED driver.
We disassemble the fluorescent lamp.

For the conversion, I took a 20 W lamp, the choke of which can easily deliver 20 W to the load. For a 10W LED, no further modifications are required. If you plan to supply more powerful LED, you need to take a converter from a more powerful lamp, or install a choke with a larger core.
Installed jumpers in the lamp ignition circuit.

I wound 18 turns of enamel wire around the inductor, solder the terminals of the wound winding to the diode bridge, apply mains voltage to the lamp and measure output voltage. In my case, the unit produced 9.7V. I connected the LED through an ammeter, which showed a current passing through the LED of 0.83A. My LED has an operating current of 900mA, but I reduced the current to increase the resource. I assembled the diode bridge on the board using a hinged method.

Remodeling scheme.

I installed the LED using thermal paste on a metal lampshade of an old table lamp.

I installed the power board and diode bridge into the body of a table lamp.

When working for about an hour, the LED temperature is 40 degrees.

To the eye, the illumination is like that of a 100-watt incandescent lamp.

I'm planning to buy +128 Add to favorites I liked the review +121 +262

Energy-saving lamps are widely used in everyday life and in production; over time they become unusable, but many of them can be restored after simple repairs. If the lamp itself fails, then from the electronic “stuffing” you can make a fairly powerful power supply for any desired voltage.

What does a power supply from an energy-saving lamp look like?

In everyday life, you often need a compact, but at the same time powerful low-voltage power supply; you can make one using a failed energy-saving lamp. In lamps, lamps most often fail, but the power supply remains in working order.

In order to make a power supply, you need to understand the operating principle of the electronics contained in an energy-saving lamp.

Advantages of switching power supplies

In recent years, there has been a clear tendency to move away from classic transformer power supplies to switching ones. This is due, first of all, to the major disadvantages of transformer power supplies, such as large mass, low overload capacity, and low efficiency.

The elimination of these shortcomings in switching power supplies, as well as the development of the element base, has made it possible to widely use these power units for devices with power from a few watts to many kilowatts.

Power supply diagram

The principle of operation of a switching power supply in an energy-saving lamp is exactly the same as in any other device, for example, in a computer or TV.

In general terms, the operation of a switching power supply can be described as follows:

• The alternating mains current is converted into direct current without changing its voltage, i.e. 220 V.
• A pulse-width converter using transistors converts DC voltage into rectangular pulses with a frequency of 20 to 40 kHz (depending on the lamp model).
• This voltage is supplied to the lamp through the inductor.

Let's look at the circuit and operating procedure of a switching lamp power supply (figure below) in more detail.

Electronic ballast circuit for an energy-saving lamp

The mains voltage is supplied to the bridge rectifier (VD1-VD4) through a limiting resistor R 0 of small resistance, then the rectified voltage is smoothed out at the filter high voltage capacitor(C 0), and through a smoothing filter (L0) is supplied to the transistor converter.

The transistor converter starts at the moment when the voltage on capacitor C1 exceeds the opening threshold of dinistor VD2. This will start the generator on transistors VT1 and VT2, resulting in self-generation at a frequency of about 20 kHz.

Other circuit elements such as R2, C8 and C11 play a supporting role, making it easier to start the generator. Resistors R7 and R8 increase the closing speed of the transistors.

And resistors R5 and R6 serve as limiting ones in the base circuits of transistors, R3 and R4 protect them from saturation, and in the event of a breakdown they play the role of fuses.

Diodes VD7, VD6 are protective, although many transistors designed to work in such devices have such diodes built-in.

TV1 is a transformer, with its windings TV1-1 and TV1-2, the feedback voltage from the output of the generator is supplied to the base circuits of transistors, thereby creating conditions for the operation of the generator.

In the figure above, the parts that must be removed when remaking the block are highlighted in red; points A–A` must be connected with a jumper.

Modification of the block

Before you begin remaking the power supply, you should decide what current power you need to have at the output; the depth of the upgrade will depend on this. So, if a power of 20-30 W is required, then the alteration will be minimal and will not require much intervention in the existing circuit. If you need to get a power of 50 watts or more, then a more thorough upgrade will be required.

It should be kept in mind that the output of the power supply will be DC voltage, not AC. It is impossible to obtain an alternating voltage with a frequency of 50 Hz from such a power supply.

Determining power

Power can be calculated using the formula:

P – power, W;

I – current strength, A;

U – voltage, V.

For example, let’s take a power supply with the following parameters: voltage – 12 V, current – ​​2 A, then the power will be:

Taking into account the overload, 24-26 W can be accepted, so the manufacture of such a unit will require minimal intervention in the circuit of a 25 W energy-saving lamp.

New parts

Adding new parts to the diagram

The added details are highlighted in red, these are:

• diode bridge VD14-VD17;
• two capacitors C 9, C 10;
• additional winding placed on ballast choke L5, the number of turns is selected experimentally.

The added winding to the inductor plays another important role as an isolation transformer, protecting against mains voltage reaching the output of the power supply.

To determine the required number of turns in the added winding, do the following:

1. a temporary winding is wound onto the inductor, approximately 10 turns of any wire;
2. connected to a load resistor with a power of at least 30 W and a resistance of approximately 5-6 Ohms;
3. connect to the network, measure the voltage at the load resistance;
4. divide the resulting value by the number of turns to find out how many volts there are per 1 turn;
5. calculate the required number of turns for a permanent winding.

A more detailed calculation is given below.

Test activation of the converted power supply

After this, it is easy to calculate the required number of turns. To do this, the voltage that is planned to be obtained from this block is divided by the voltage of one turn, the number of turns is obtained, and approximately 5-10% is added to the result obtained in reserve.

W=U out /U vit, where

W – number of turns;

U out – required output voltage of the power supply;

U vit – voltage per turn.

Winding an additional winding on a standard inductor

The original inductor winding is under mains voltage! When winding an additional winding on top of it, it is necessary to provide inter-winding insulation, especially if a PEL type wire is wound, in enamel insulation. For interwinding insulation, you can use polytetrafluoroethylene tape to seal threaded connections, which is used by plumbers; its thickness is only 0.2 mm.

The power in such a block is limited by the overall power of the transformer used and the permissible current of the transistors.

High Power Power Supply

This will require a more complex upgrade:

• additional transformer on a ferrite ring;
• replacing transistors;
• installing transistors on radiators;
• increasing the capacity of some capacitors.

As a result of this modernization, a power supply with a power of up to 100 W is obtained, with an output voltage of 12 V. It is capable of providing a current of 8-9 amperes. This is enough to power, for example, a medium-power screwdriver.

The diagram of the upgraded power supply is shown in the figure below.

100W power supply

As can be seen in the diagram, resistor R0 has been replaced with a more powerful one (3-watt), its resistance has been reduced to 5 Ohms. It can be replaced with two 2-watt 10 ohm ones, connecting them in parallel. Further, C 0 - its capacity is increased to 100 μF, with an operating voltage of 350 V. If it is undesirable to increase the dimensions of the power supply, then you can find a miniature capacitor of such a capacity, in particular, you can take it from a point-and-shoot camera.

To ensure reliable operation of the unit, it is useful to slightly reduce the values ​​of resistors R 5 and R 6, to 18–15 Ohms, and also increase the power of resistors R 7, R 8 and R 3, R 4. If the generation frequency turns out to be low, then the values ​​of capacitors C 3 and C 4 – 68n should be increased.

The most difficult part may be making the transformer. For this purpose, ferrite rings of appropriate sizes and magnetic permeability are most often used in pulse blocks.

The calculation of such transformers is quite complicated, but there are many programs on the Internet with which this is very easy to do, for example, “Pulse transformer calculation program Lite-CalcIT”.

What does a pulse transformer look like?

The calculation carried out using this program gave the following results:

A ferrite ring is used for the core, its outer diameter is 40, its inner diameter is 22, and its thickness is 20 mm. Primary winding PEL wire - 0.85 mm 2 has 63 turns, and two secondary ones with the same wire - 12.

The secondary winding must be wound into two wires at once, and it is advisable to first slightly twist them together along the entire length, since these transformers are very sensitive to the asymmetry of the windings. If this condition is not met, then the diodes VD14 and VD15 will heat up unevenly, and this will further increase the asymmetry, which will ultimately damage them.

But such transformers easily forgive significant errors when calculating the number of turns, up to 30%.

Since this circuit was originally designed to work with a 20 W lamp, transistors 13003 were installed. In the figure below, position (1) is medium power transistors; they should be replaced with more powerful ones, for example, 13007, as in position (2). They may have to be installed on a metal plate (radiator) with an area of ​​about 30 cm2.

Trial

A test run should be carried out with certain precautions taken so as not to damage the power supply:

1. The first test run should be carried out using a 100 W incandescent lamp to limit the current to the power supply.
2. Be sure to connect a 3-4 Ohm load resistor with a power of 50-60 W to the output.
3. If everything went as expected, let it run for 5-10 minutes, turn it off and check the degree of heating of the transformer, transistors and rectifier diodes.

If no errors were made during the process of replacing parts, the power supply should work without problems.

If a trial run shows the unit is working, all that remains is to test it in full load mode. To do this, reduce the resistance of the load resistor to 1.2-2 Ohms and connect it directly to the network without a light bulb for 1-2 minutes. Then turn off and check the temperature of the transistors: if it exceeds 60 0 C, then they will have to be installed on radiators.

Despite the small size of energy-saving lamps, they contain many electronic components. In terms of its structure, it is an ordinary tubular fluorescent lamp with a miniature bulb, but only rolled into a spiral or other compact spatial line. That is why it is called compact fluorescent lamp(abbreviated as CFL).

And it is characterized by all the same problems and malfunctions as large tubular light bulbs. But the electronic ballast of a light bulb that has stopped shining, most likely due to a burnt-out filament, usually remains operational. Therefore, it can be used for any purpose as a switching power supply (abbreviated as UPS), but with preliminary modification. This will be discussed further. Our readers will learn how to make a power supply from an energy-saving lamp.

What is the difference between UPS and electronic ballast

Let us immediately warn those who expect to receive a powerful power source from CFLs - it is impossible to obtain more power as a result of simply altering the ballast. The fact is that in inductors that contain cores, the working magnetization zone is strictly limited by the design and properties of the magnetizing voltage. Therefore, the pulses of this voltage created by the transistors are precisely selected and determined by the circuit elements. But such a power supply from electronic ballasts is quite sufficient to power LED strip. Moreover, the switching power supply from an energy-saving lamp corresponds to its power. And it can be up to 100 W.

The most common CFL ballast circuit is based on a half-bridge (inverter) circuit. This is a self-oscillator based on a TV transformer. Winding TV1-3 magnetizes the core and performs the function of a choke to limit the current through the EL3 lamp. Windings TV1-1 and TV1-2 provide positive feedback for the appearance of voltage that controls transistors VT1 and VT2. The diagram in red shows the CFL bulb with the elements that ensure its launch.

Example of a common CFL ballast circuit

All inductors and capacitances in the circuit are selected so as to obtain precisely dosed power in the lamp. The performance of transistors is related to its value. And since they do not have radiators, it is not recommended to try to get significant power from the converted ballast. The ballast transformer does not have a secondary winding from which the load is powered. This is the main difference between it and the UPS.

What is the essence of ballast reconstruction?

To be able to connect the load to a separate winding, you must either wind it on inductor L5, or use an additional transformer. Converting ballast into a UPS involves:

To further convert the electronic ballast into a power supply from an energy-saving lamp, you need to make a decision regarding the transformer:

• use the existing throttle by modifying it;
• or use a new transformer.

Transformer from choke

Next we will consider both options. In order to use the inductor from the electronic ballast, it must be desoldered from the board and then disassembled. If it uses an W-shaped core, it contains two identical parts that are connected to each other. In this example, orange adhesive tape is used for this purpose. It is carefully removed.

Removing the tape holding the core halves together

The core halves are usually glued together so that there is a gap between them. It serves to optimize the magnetization of the core, slowing down this process and limiting the rate of current rise. We take our pulse soldering iron and heat the core. We apply it to the soldering iron where the halves are joined.

Having disassembled the core, we get access to the coil with the wound wire. It is not recommended to unwind the winding that is already on the reel. This will change the magnetization mode. If free place between the core and the coil allows you to wrap one layer of fiberglass to improve the insulation of the windings from each other, you need to do this. And then wind ten turns of the secondary winding with a wire of suitable thickness. Since the power of our power supply will be small, a thick wire is not needed. The main thing is that it fits on the coil, and the halves of the core are put on it.

Having wound the secondary winding, we assemble the core and secure the halves with adhesive tape. We assume that after testing the power supply it will become clear what voltage is created by one turn. After testing, we will disassemble the transformer and add the required number of turns. Typically, the rework aims to make a voltage converter with a 12 V output. This allows you to get when using stabilization Charger for battery. At the same voltage, you can make a driver for LEDs from an energy-saving lamp, and also charge a flashlight powered by a battery.

Since the transformer of our UPS will most likely have to be rewinded, it is not worth soldering it into the board. It is better to solder the wires sticking out from the board, and solder the leads of our transformer to them for the duration of testing. The ends of the secondary winding leads must be cleared of insulation and covered with solder. Then, either on a separate socket or directly at the terminals of the wound winding, you need to assemble a rectifier using high-frequency diodes according to a bridge circuit. For filtering during voltage measurement, a 1 µF 50 V capacitor is sufficient.

UPS testing

But before connecting to a 220 V network, a powerful resistor must be connected in series with our block, converted from a lamp with our own hands. This is a safety measure. If a short circuit current flows through the pulse transistors in the power supply, the resistor will limit it. In this case, a 220 V incandescent light bulb can become a very convenient resistor. In terms of power, it is enough to use a 40–100-watt lamp. At short circuit in our device the light bulb will glow.

Next, we connect the multimeter probes to the rectifier in the DC voltage measurement mode and apply a voltage of 220 V to electrical circuit with light bulb and power supply board. Twists and exposed live parts must be insulated first. To supply voltage, it is recommended to use a wired switch and place the light bulb in a liter jar. Sometimes they burst when turned on, and fragments scatter to the sides. Usually the tests go without problems.

More powerful UPS with separate transformer

They allow you to determine the voltage and the required number of turns. The transformer is modified, the unit is tested again, and after that it can be used as a compact power source, which is much smaller than an analogue based on a conventional 220 V transformer with a steel core.

To increase the power of the power source, you need to use a separate transformer, made similarly from a choke. It can be extracted from a higher power light bulb that has burned out completely along with the semiconductor ballast products. The basis is the same circuit, which differs by connecting an additional transformer and some other parts shown in red lines.

The rectifier shown in the image contains fewer diodes compared to the bridge rectifier. But for its operation it will require more turns of the secondary winding. If they do not fit into the transformer, a rectifier bridge must be used. A more powerful transformer is made, for example, for halogen lamps. Anyone who has used a regular transformer for a lighting system with halogens knows that they are powered by a fairly large current. Therefore, the transformer turns out to be bulky.

If transistors are placed on radiators, the power of one power supply can be significantly increased. And in terms of weight and dimensions, even several of these UPSs for working with halogen lamps will be smaller and lighter than one transformer with a steel core of equal power. Another option for using functional housekeeper ballasts could be their reconstruction for LED lamp. Converting an energy-saving lamp into an LED design is very simple. The lamp is disconnected, and a diode bridge is connected instead.

A certain number of LEDs are connected at the bridge output. They can be connected to each other in series. It is important that the LED current is equal to the current in the CFL. Energy-saving light bulbs can be called a valuable mineral in the era of LED lighting. They can be used even after their service life has expired. And now the reader knows the details of this application.