Energy-saving lamps are gaining more and more popularity, allowing you to save energy, they still have an even white light, there are also warm light lamps that are similar in color to incandescent lamps. But unfortunately, energy-saving lamps also do not last forever, someone just throws them away, and someone ... makes useful homemade products out of them.
In this article, we will look at how to make a simple switching power supply from an energy-saving lamp. In most cases, in an energy-saving lamp, the filaments in the bulb fail, and the electronic part remains intact.
We take a faulty energy-saving lamp. And with the help of a screwdriver, pry off the two halves of the case. We pass along the contour and alternately bend one half from the other.
Approximately all energy-saving lamps are made according to this scheme:
In order to make a switching power supply, we will change it to this form:
First, we remove all the pins, two capacitors and diodes (if any), as you can see in the photo, I didn’t have them.
We remove the pulse choke, two options are possible here, the first is that the secondary winding is wound into the free space of the choke and it is installed back on the board. In this case, you will not be able to get more power. The second way - a pulse transformer is wound, for example, on a ferrite ring. When installing radiators on transistors, you can get a power of 100W or more.
I didn’t need a lot of power, the goal was to power a meter of white LED strip, to make something like a kitchen night light :). I also chose a supply voltage of about 8-10 volts so that the tape does not glow very brightly, in this mode of operation it will last much longer.
The throttle is removed, we disassemble it, it is quite easy to do this, unwind the yellow synthetic film, and take out the two halves of the ferrite. Before winding the secondary winding, it is necessary to make insulation, simply wind electrical cardboard, plain paper, or plumbing tape on the primary winding. Next, we wind a few turns.
We also make insulation and display the edges of the winding.
We assemble the transformer in the reverse order, I used glue like "Second".
We install the transformer on the board. We connect the jumper P1 and P4 (see the diagram).
For testing, I connected the rest of the coil of LED strip, after rectifying the voltage with a diode and a capacitor. The output voltage is 9 volts.
Everything switching power supply from an energy-saving lamp is ready, it works, nothing is heated on the board.
A fluorescent lamp is a rather complex mechanism. The design of energy-saving lamps contains many different small components, which together provide the lighting that such a device produces. The basis of the entire design of energy-saving devices is a glass tube filled with mercury vapor and an inert gas.
Electrodes, cathode and anode are installed at both ends of this tube. After applying current to them, they begin to heat up. Having reached the required temperature, they release electrons that hit the mercury molecules and it begins to emit ultraviolet light.
Ultraviolet is converted into a spectrum visible to the human eye thanks to the phosphor, which is located in the tube. Thus, the lamp lights up after a while. Typically, the rate of ignition of the lamp depends on the period of its development. The longer the lamp has been on, the longer the interval between switching on and full ignition will be.
To understand the purpose of each of the UPS components, it is necessary to analyze separately what functions they perform:
Thanks to the correct placement and careful selection of the characteristics of all the listed components, we get the power supply we need the power for further use.
It is very similar in structure to a switching power supply, which is why you can make a switching power supply very easily and quickly. For alteration, it is necessary to install a jumper and additionally install a transformer that generates pulses and is equipped with a rectifier.
To lighten the UPS, the glass fluorescent lamp and some of the structural components have been removed and replaced with a special connector. You may have noticed that it only takes a few simple steps to make the change, and that should be enough.
Board with energy-saving lamp
The output power rating is limited by the size of the transformer used, the maximum possible throughput rating of the main transistors, and the dimensions of the cooling system. To increase the power a little, it is enough to wind more windings on the inductor.
The main key characteristic of a switching power supply is the ability to adapt to the performance of the transformer used in the design. And the fact that the reverse current does not need to pass through the transformer, which we made ourselves, makes it much easier for us to calculate the rated power of the transformer.
Thus, most of the errors in the calculation become insignificant due to the use of such a scheme.
To save money, capacitors with a small capacitance index are used. It is from them that the ripple of the input voltage will depend. To reduce the ripple, it is necessary to increase the volume of capacitors, too, to increase the ripple index, only in the reverse order.
To reduce the size and improve the compactness, it is possible to use capacitors on electrolytes. For example, you can use such capacitors that are built into photographic equipment. They have a capacity of 100µF x 350V.
To provide a bp with an indicator of twenty watts, it is enough to use a standard circuit from energy-saving lamps and not at all winding additional windings on transformers. In the case when the throttle has free space and can additionally fit the turns, you can add them.
Thus, two or three dozen turns of winding should be added so that it is possible to recharge small devices or use the UPS as an amplifier for equipment.
20 watt power supply circuit
If you need a more efficient increase in power, you can use the simplest copper wire, coated with varnish. It is specially designed for winding. Make sure that the insulation on the standard inductor winding is good enough, as this part will be under the value of the incoming current. It should also be protected from secondary turns with paper insulation.
The current power supply model is 20 watts.
For insulation, we use special cardboard with a thickness of 0.05 mm or 0.1 mm. In the first case, two words are needed, in the second one is enough. We use the cross section of the winding wire from the maximum large, the number of turns will be selected by sampling. Usually, only a few turns are needed.
Having done all the necessary steps, you get a power supply of 20 watts and an operating temperature of the transformer is sixty degrees, the transistor is forty-two. It will not work to make more power, since the dimensions of the inductor are limited and it will not work to make more windings.
Reducing the transverse diameter of the wire used will, of course, increase the number of turns, but this will only affect the power in a minus.
In order to be able to increase the power of the power supply unit to hundreds of watts, it is necessary to additionally tighten the pulse transformer and expand the capacitance of the filter capacitor to 100 farads.
Schematic 100 watt PSU
To lighten the load and reduce the temperature of the transistors, radiators should be added to them for cooling. With this design, the efficiency will be around ninety percent.
Transistor 13003 should be connected
A 13003 transistor should be connected to the electronic ballast, which can be fixed with a shaped spring. They are advantageous in that with them there is no need to install a gasket due to the lack of metal pads. Of course, their heat transfer is much worse.
It is best to fasten with M2.5 screws, with pre-installed insulation. It is also possible to use thermal paste that does not transmit mains voltage.
Make sure that the transistors are well insulated, as current flows through them and a short circuit is possible if the insulation is poor.
The connection is made using an incandescent lamp. It will serve as a protective mechanism and is connected in front of the power supply.
Energy-saving power supplylamps.
If the electronic ballast fails, it can be 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 (PSU). The only thing in which the electronic ballast circuit differs from a real pulse power supply is the absence of an isolation transformer and a rectifier.
Let's see what's interesting on it.
- Diodes - 6 pcs. High-voltage (220 Volts) are usually low-power.
Throttle. Removes network interference.
Medium power transistors are usually MJE13003.
high voltage electrolyte. The capacitance is small (4.7 microfarads), at 400 volts.
Capacitors of different capacities, all 250 volts.
Two high frequency transformers.
Several resistors.
The purpose of the circuit elements of a switching power supply.
R0 - limits the peak current flowing through the rectifier diodes at the moment of switching on, also often acts as a fuse.
VD1 ... VD4 - bridge rectifier.
L0, C0 - power filter.
R1, C1, VD2, VD8 - converter start circuit.
The launch node works as follows. Capacitor C1 is charged from the source through resistor R1. When the voltage on the capacitor C1 reaches the breakdown voltage of the VD2 dinistor, the dinistor unlocks itself and unlocks the VT2 transistor, causing self-oscillations. After the onset of generation, rectangular pulses are applied to the cathode of the VD8 diode and the negative potential securely locks the VD2 dinistor.
R2, C11, C8 - make it easier to start the converter.
R7, R8 - improve the locking of transistors.
R5, R6 - limit the current of the bases of transistors.
R3, R4 - prevent saturation of transistors and act as fuses during breakdown of transistors.
VD7, VD6 - protect transistors from reverse voltage.
TV1 - feedback transformer.
L5 - ballast choke.
C4, C6 - separating capacitors, on which the supply voltage is divided in half.
TV2 - pulse transformer.
VD14, VD15 - pulse diodes.
C9, C10 - filter capacitors.
The difference between the lamp circuit and the pulse power supply.
This is one of the most common electrical circuits for energy-saving lamps.
To convert the economy lamp circuit into a switching power supply, it is enough to install only one jumper between the points A - A' and add a pulse transformer with a rectifier. Items that need to be removed are marked in red.
And this is already a complete switching power supply circuit, assembled on the basis of an economy lamp using an additional pulse transformer.
To simplify, the fluorescent lamp and a few parts have been removed and replaced with a jumper.
As you can see, the circuit does not require major changes. Additional elements added to the scheme are marked in red.
The power of the power supply is limited by the overall power of the pulse transformer, the maximum allowable current of key transistors and the size of the cooling radiator, if it is used.
A low power power supply can be built by winding the 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 required 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 want to get a power supply unit with a power of more than 100 watts, and a ballast from a 20-30 watt lamp is used, then you will have to make small changes to the electronic ballast circuit.
In particular, it may be necessary 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 is insufficient, then the base current of the transistors will have to be increased by decreasing the values of the resistors R5, R6. In addition, you will have to increase the power of the 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 self-excited half-bridge switching power supplies 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 almost always forgive errors in calculations.
Winding a pulse transformer is not so difficult.
Input filter capacitance and voltage ripple.
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In the input filters of electronic ballasts, due to economy, 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 PSU, you need to increase the capacitance of the input filter capacitor. It is desirable 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 PSU 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 should be replaced with a more powerful one. |
If a compact power supply is required, then electrolytic capacitors can be used, which are used in flash lamps of film "soap dishes". For example, disposable cameras have unmarked miniature capacitors, their capacity is approximately 100µF x 350V.
20 watt power supply.
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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 a charger or a small power amplifier. The picture shows that one layer of insulated wire was wound over the existing winding. MGTF wire (stranded wire in fluoroplastic insulation) was used. However, in this way it is possible to obtain a power of only a few watts, since most of the window will be occupied by the insulation of the wire, and the cross section of the copper itself will be small. If you want to greater power, then you can use an ordinary copper varnished winding wire. |
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Attention!
The original inductor winding is under mains voltage! With the refinement described above, be sure to take care of reliable 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 pad is necessary!
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The winding of the inductor is covered with a synthetic film, although it often happens that the winding of these chokes is not protected at all. |
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We wind two layers of electric cardboard 0.05 mm thick or one layer 0.1 mm thick over the film. If there is no electric cardboard, we use any paper that is suitable in thickness. |
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We wind the secondary winding of the future transformer over the insulating gasket. The cross section of the wire should be chosen as large as possible. The number of turns is selected experimentally (there will be few of them). |
Thus, it was possible to obtain power at a load of 20 watts at a transformer temperature of 60ºC, and transistors - 42ºC. To get even more power, at a reasonable temperature of the transformer, was not allowed by the too small area of the window of the magnetic circuit and the resulting cross section of the wire.
100 watt power supply.
To increase the power of the power supply, it was necessary to wind the TV2 pulse transformer and increase the capacitance of the mains voltage filter capacitor C0 to 100µF.
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Since the efficiency of the power supply is not at all equal to 100%, I had to screw some kind of radiators to the transistors. After all, if the efficiency of the block is even 90%, you still have to dissipate 10 watts of power. In this electronic ballast, transistors 13003 pos. 1 of such a design were installed, which is designed to be attached to a radiator using shaped springs. These transistors do not need gaskets, since they are not equipped with a metal pad, but they also give off heat much worse. It is better to replace them with transistors 13007 pos.2 with holes so that they can be screwed to the radiators with ordinary screws. In addition, 13007 have several times the maximum permissible currents. You can safely screw both transistors onto one radiator. Only, the cases of both transistors must be insulated from the case of the heatsink, even if the heatsink is inside the case of the electronic device. Fastening is conveniently carried out with M2.5 screws, on which insulating washers and pieces of an insulating tube (cambric) must first be put on. It is allowed to use heat-conducting paste KPT-8, since it does not conduct current. |
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Image of the connection of the transistor with the radiator: 1. Screw M2,5. 2. Washer M2,5. 3. Insulating washer M2,5. 4. Transistor housing. 5. Gasket - a piece of tube ( cambric). 6. Gasket - mica, ceramic, fluoroplastic, etc. 7. Cooling radiator. |
Attention!
Transistors are under mains voltage, so insulating gaskets must provide conditions electrical safety!
Rectifier.
All secondary rectifiers of a half-bridge switching power supply must be full-wave. If this condition is not met, then the main line may enter saturation.
There are two widely used schemes full-wave rectifiers.
1. Bridge circuit.
2. Scheme with a 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 arrangement can lead to core saturation.
However, it is the zero-point circuits that are used when it is required to obtain large 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.
Rectifiers of computer power supplies are made according to the scheme with a zero point. With a power output of 100 watts and a voltage of 5 volts, even on Schottky diodes, 8 watts can be dissipated.
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 so that later you don’t look for where half the power has disappeared.
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In low-voltage rectifiers, it is better to use a zero-point circuit. Moreover, with manual winding, you can simply wind the winding in two wires. |
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How to properly connect a switching power supply to the network? |
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For setting up switching power supplies, such a switching circuit is usually used. Here, the incandescent lamp is used as a ballast with a non-linear characteristic and protects the UPS from failure in abnormal situations. The lamp power is usually chosen close to the power of the tested switching power supply. When the pulse power supply is idling or at low load, the resistance of the filament of the lamp's kakala 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 current limitation to a safe value. |
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This drawing shows a diagram of a bench for testing and adjusting a pulsed power supply that meets the standards electrical safety. The difference between this circuit and the previous one is that it is equipped with an isolation transformer, which provides galvanic isolation of the investigated UPS from the lighting network. The SA2 switch allows you to block the lamp when the power supply delivers more power. |
How to set up a switching power supply?
The power supply, assembled on the basis of a serviceable electronic ballast, does not require special adjustment.
It must be connected to a load dummy and make sure that the PSU is able to deliver the calculated power.
During the run under maximum load, you need to follow the dynamics of the temperature increase of the transistors and the 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, then you need to install them on radiators.
If a homemade choke from a CFL is used as a pulse transformer, and its temperature exceeds 60 ... 65ºС, then the load power must be reduced.
The range of modern stores is very large. Every day there are new things. This also applies to lighting devices, which are becoming more advanced. The main differences between them are in brightness, economic characteristics and the creation of the necessary comfort for the eyes.
Most manufacturers tried to create a product similar to a conventional incandescent lamp, only with more advanced features. Which will reduce the need for electricity, while the degree of their heating and the 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 overestimated. And to make a power supply with your own hands, you will not need a lot of time and money.
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:
The power supply unit from the ballast of energy-saving lamps is a great option for creating cheap and high-quality lighting with your own hands, without high costs. In this way, you can replace all the lamps in your home.
To create a PSU from an energy-saving lamp with your own hands, first you need to cut a circle from the textolite according to the size of the product. Then you need to draw round stripes on this form. To do this, you can use any improvised means that you have on the farm. In this case, the accuracy and evenness of the lines is important. After all, according to this scheme, LEDs will be attached. While the product dries, you can prepare other necessary parts to create a power supply. Among them - soldering all the necessary parts, drilling holes with a drill that are needed for fastening, fastening all the elements together. All parts are attached to a special glue resistant to different temperature conditions.
In order to create a PSU 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 quality product that will help you save on electricity.
There are also many other ways to create a PSU from an energy-saving one, which are completely affordable and within the power of almost everyone.
Well-known to most users, energy-saving lamps, despite their popularity, quickly become unusable and usually cannot be permanently restored. However, if only one lamp burns out in them, and the electronic ballast circuit that feeds it remains relatively intact, it can be used as an independent power supply (see photo).
The artificial "life extension" of energy-saving products, in which only one illuminator burned out, makes it possible to obtain a cheap and relatively powerful UPS, the output voltage of which can be chosen arbitrarily.
Energy-saving lamps produced by the domestic industry, as well as their widespread Chinese counterparts, have a similar electronic circuit (electronic ballast) operating on the principle of pulse conversion. Such an arrangement of an energy-saving lamp provides it with the following obvious advantages:
Additional Information. The energy-saving switching power supply scheme under consideration has only one small drawback, which consists in its low reliability and frequent failure.
The essence of the operation of the electronic ballast device (the so-called ballast) is quite simple and is as follows:
To better understand the principle by which energy-saving lamps work, a closer look at the electronic circuit used in them will be required.
The principal approach to reuse of an energy-saving product involves the use of an electronic board that has not yet burned out as a switching power supply.
Note! If the lamp included in the lighting network is still on, but at the same time it starts to blink frequently and turn off on its own, this is a sure sign that with a certain probability it can be attributed to already burning out lamps.
To understand how energy-saving lamps work, you need to understand their electronic circuit (see the figure below).
The working scheme of the electronic ballast includes the following mandatory elements:
Diodes VD7 and VD6 perform a protective function, and transformers TV1-1 and TV1-2 form a feedback circuit that increases the stability of the generation process. The red color in the figure, which shows the lamp (more precisely, its diagram), highlights a set of parts that must be removed when finalizing the electronic unit.
Important! The control points A-A` indicated in the figure must be connected by a metal jumper.
Before you make a power supply from an energy-saving lamp, first of all, you will need to decide on the power that will be required from it in each case. This parameter will determine the degree of modernization of the electronic part, which ensures the possibility of normal operation of the equipment connected to it.
So, with a small operating power of the future power supply, the alteration of the electronic ballast will affect only a small part of the entire circuit (see figure).
If it is supposed to make a switching power supply from an energy-saving lamp, designed for significant loads (to connect a pulsed soldering iron, for example), its load characteristic must be increased. This will require a significant refinement of the electronic ballast circuit based on an output power of more than 50 watts.
To calculate this parameter, remember that it is defined as the product of the output current and the operating voltage. That is, if a 50-watt pulsed soldering iron is designed for a voltage of 25 volts, then a home-made power supply must provide an output current of at least 2 amperes (the upgraded circuit is given below).
In addition to a soldering iron, any medium-power low-voltage lamp can work from such a switching power supply.
In the revised scheme No. 1, new parts are highlighted in red and indicate the following elements:
Important! It performs the function of a separating element, which excludes the possibility of 220 V mains voltage entering the output of the power module.
Let's figure out what can be done to protect the PSU output from overloads due to the correct choice of the number of turns of the output coil.
To calculate the required number of turns in the removable winding L5, you need to experiment a little, that is, proceed as follows:
At the end of the experiment, the required number of turns necessary to obtain a given output voltage is determined by dividing its value by the previously obtained result.
When modifying the output coil, always remember that the primary winding is under high voltage. Therefore, all its design changes should be carried out only on a converter device disconnected from the network.
When winding additional turns on a choke already in the electronic ballast, one should not forget about the winding insulation, which is mandatory for PEL type wires (in thin enamel insulation).
As such insulation, wound in several layers, a special polytetrafluoroethylene tape, often used to seal threaded joints, should be used.
Additional Information. Such an insulating tape has a thickness of only 0.2 mm and is most often used in repair and plumbing work.
The finished winding is loaded onto a diode bridge, the rectified voltage from which is supplied to the load (this can be an ordinary low-voltage light bulb, for example). The output power in a power supply made according to this scheme is usually limited by the size of the transformer used and the permissible currents of the switched device on transistors TV1 and TV2.
To obtain a power supply of greater power, to which it will be possible to connect a pulse soldering iron, for example, more complex refinement will be required (see the diagram in the figure below).
The structure of the finalized part of the scheme, highlighted in red in the figure, includes the following elements:
In addition, it will be necessary to replace the switching transistors TV1 and TV2 with more powerful samples with their simultaneous installation on cooling radiators.
Note! For better smoothing of ripples, the capacitance of most capacitors (including the output C9 and C10) will need to be slightly increased.
As a result of the modernization, a partially burnt energy-efficient lamp turns into a fairly powerful power supply (up to 100 watts). At the same time, its output voltage can take values from 12 volts and higher with an operating current in the load up to 8-9 amperes. The indicated parameters of a device converted from a burned-out lamp may well be enough to power a simple screwdriver, for example.
In conclusion, we note that in order to use a burnt out energy-saving lamp for the independent manufacture of a switching power supply (UPS), certain skills in handling an electric soldering iron are needed. In addition, you will need the ability to deal with electronic circuits at least at the level of understanding of the material given in this review.
