The failure of the battery of a cordless screwdriver or other power tool is not the most pleasant event, especially considering that the cost of replacing this element is comparable to the price of a new device. But perhaps unplanned expenses can be avoided? This is quite possible if you replace the battery with a simple homemade energy-saving pulse-type power supply, with which the tool can be charged from the mains. And the components for it can be found in an affordable and ubiquitous product - this.
Energy saving light bulb ballast source
DIY UPS from a fluorescent lamp
In most cases, to assemble a UPS, the electronic choke of the epra should only be slightly modified (with a two-transistor circuit) by using a jumper, and then connected to a pulse transformer and rectifier. Some components are simply removed as unnecessary.
Homemade power supply
For weak power supplies (from 3.7 V to 20 watts), you can do without a transformer. It will be enough to add a few turns of wire to the magnetic circuit of the choke lamp in the ballast, if, of course, there is room for this. A new winding can be made directly on top of the existing one.
MGTF brand wire with fluoroplastic insulation is perfect for this. Typically, little wire is required, while almost the entire lumen of the magnetic circuit is occupied by insulation, which determines the low power of such devices. To increase it, you will need a pulse transformer.
Pulse transformer
A feature of the described UPS version is the ability to adapt to some extent to the parameters of the transformer, as well as the absence of a circuit feedback passing through this element. This connection diagram allows you to do without a particularly accurate calculation of the transformer.
As practice has shown, even with gross errors (deviations of more than 140% were allowed), the UPS can be given a second life and it turned out to be operational.
The transformer is made on the basis of the same inductor, on which the secondary winding is wound from varnished winding copper wire. In this case, it is important to pay special attention to the inter-winding insulation made from a paper gasket, because the “native” winding of the inductor will operate under mains voltage.
Even if it is covered with synthetic protective film, it is still necessary to wind several layers of electrical cardboard or at least ordinary paper with a total thickness of 100 microns (0.1 mm) on top of it, and the varnished wire of the new winding can be laid on top of the paper.
The diameter of the wire should be the largest possible. There will not be many turns in the secondary winding, so their optimal number can be selected experimentally.
Using the specified materials and technology, you can obtain a power supply with a power of 20 or a little more watts. IN in this case its value is limited by the area of the magnetic circuit window and, accordingly, by the maximum diameter of the wire that can be placed there.
Rectifier
To avoid saturation of the magnetic circuit, only full-wave output rectifiers are used in the UPS. In the event that the pulse transformer operates to reduce the voltage, the most economical is the zero-point circuit, but to implement it you will need to make two completely symmetrical secondary windings. When winding manually, you can wind it in two wires.
A standard rectifier assembled according to the " diode bridge"made of ordinary silicon diodes, is not suitable for a switching UPS, since out of 100 W of transmitted power (at a voltage of 5 V), about 32 W or more will be lost on it. Assembling a rectifier using powerful pulse diodes will be too expensive.
UPS setup
After assembling the UPS, you need to connect it to the maximum load and check how hot the transistors and transformer are. The limit for a transformer is 60 - 65 degrees, for transistors - 40 degrees. When the transformer overheats, they increase the cross-section of the wire or the overall power of the magnetic circuit, or perform both actions together. If the transformer is made from a lamp ballast choke, it will most likely not be possible to increase the cross-section of the wire and you will have to limit the connected load.
How to make an LED power supply with increased power
Sometimes the standard power of a lamp's electronic ballast is not enough. Let's imagine a situation: there is 23 W, but you need to get a power source for the charger with parameters of 12V/8A.
In order to implement your plan, you will have to get a computer power supply, which turned out to be unclaimed for some reason. The power transformer along with the R4C8 chain should be removed from this block, which performs the function of protecting power transistors from overvoltage. The power transformer should be connected to the electronic ballast instead of the choke.
It was experimentally found that this type The UPS allows you to remove power up to 45 W with slight overheating of the transistors (up to 50 degrees).
To avoid overheating, it is necessary to install a transformer with an increased core cross-section in the transistor bases, and install the transistors themselves on a radiator.
Possible mistakes
As already mentioned, including a conventional low-frequency diode bridge in the circuit as an output rectifier is impractical, and with increased power of the UPS it is even less worth doing this.
It is also pointless to try to wind the base windings directly on the power transformer for the sake of simplifying the circuit. In the absence of load, significant losses will occur due to the fact that the maximum current will flow into the bases of the transistors.
As the load current increases, the transformer used also increases the current in the bases of the transistors. Practice shows that when the load power reaches 75 W, saturation occurs in the magnetic circuit of the transformer. This leads to deterioration in the performance of transistors and their overheating.
To avoid this, you can wind the current transformer yourself by doubling the cross-section of the core or by folding two rings together. You can also double the diameter of the wire.
There is a way to get rid of the base transformer that performs the intermediate function. To do this, the current transformer is connected through a powerful resistor to a separate winding of the power heater, implementing a voltage feedback circuit. The disadvantage of this option is that the current transformer constantly operates in saturation mode.
The transformer cannot be connected in parallel with the choke present in the ballast converter. Due to the decrease in the total inductance, the frequency of the power supply will increase. This phenomenon will lead to increased losses in the transformer and overheating of the output rectifier transistors.
The increased sensitivity of Schottky diodes to exceeding the reverse voltage and current values should be taken into account. Trying to install, say, a 5-volt diode into a 12-volt circuit will likely result in the element failing.
Do not try to replace transistors and diodes with domestic ones, for example, KT812A and KD213. This clearly leads to deterioration in the performance of the device.
How to connect a UPS to a screwdriver
The power tool must be disassembled by unscrewing all screws. Typically, the screwdriver body consists of two halves. Next, you should find the wires that connect the engine to the battery. These wires can be connected to the UPS output using soldering or heat-shrink tubing; twisted wires are not recommended.
To enter the wire from the power supply, a hole must be made in the tool body. It is important to take measures to prevent the wire from being pulled out in the event of careless movements or accidental jerks. The simplest option is to crimp the wire inside the housing near the hole with a clip made from a short piece of soft wire folded in half (aluminum will do). Having dimensions exceeding the diameter of the hole, the clip will not allow the wire to come off and fall out of the housing in the event of a jerk.
As you can see, an energy-saving light bulb, even if it has served its intended life, can bring considerable benefits to its owner. A UPS assembled on the basis of its components can be successfully used as a source of energy for cordless power tools or a charger.
Video
This video will tell you how to assemble a power supply unit (PSU) from energy-saving lamps.
Modern fluorescent light bulbs are a real godsend for budget-conscious consumers. They shine brightly, last longer than incandescent bulbs and consume much less energy. At first glance, there are only advantages. However, due to the imperfections of domestic power grids, they exhaust their resources much earlier than the deadlines stated by the manufacturers. And often they do not even have time to “cover” the costs of their acquisition.
But don’t rush to throw away the broken “housekeeper”. Considering the considerable initial cost of fluorescent light bulbs, it is advisable to “squeeze” the maximum out of them, using all possible resources to the last. After all, right under the spiral there is a circuit of a compact high-frequency converter installed in it. For a knowledgeable person, this is a whole “Klondike” of all kinds of spare parts.
Disassembled lamp
General information
Battery
In fact, such a circuit is an almost ready-made switching power supply. The only thing missing is an isolation transformer with a rectifier. Therefore, if the flask is intact, you can try to disassemble the body without fear of mercury fumes.
By the way, it is the lighting elements of light bulbs that most often fail: due to resource burnout, merciless operation, too low (or high) temperatures, etc. The internal boards are more or less protected by a sealed case and parts with a safety margin.
We advise you to accumulate a certain number of lamps before starting repair and restoration work (you can ask around at work or with friends - usually there is enough of this kind of stuff everywhere). It’s not a fact that all of them will be repairable. In this case, what is important to us is the performance of the ballast (i.e., the board built inside the light bulb).
You may have to do a little digging the first time, but then in an hour you can assemble a primitive power supply for devices of suitable power.
If you plan to create a power supply, choose more powerful fluorescent lamp models, starting from 20 W. However, less bright light bulbs will also come into use - they can be used as donors of the necessary parts.
And as a result, from a couple of burnt-out housekeepers it is quite possible to create one completely capable model, be it a working light bulb, a power supply, or Charger for batteries.
Most often, self-taught craftsmen use housekeeper ballast to create 12-watt power supplies. They can be connected to modern LED systems, because 12 V is the operating voltage of most of the most common household devices, including lighting.
Such blocks are usually hidden in furniture, so appearance the node is not particularly important. And even if the craft turns out to be sloppy in appearance, it’s okay, the main thing is to take care of maximum electrical safety. To do this, carefully check the created system for operability, leaving it to work in test mode for a long time. If there are no voltage surges or overheating, it means you did everything right.
It is clear that you will not extend the life of the updated light bulb much - sooner or later the resource is exhausted anyway (the phosphor and filament burn out). But you must agree, why not try to restore a failed lamp within six months to a year after purchase.
Disassembling the lamp
So, we take a non-working light bulb, find the junction of the glass bulb with the plastic body. Carefully pry the halves with a screwdriver, gradually moving along the “belt”. Usually these two elements are connected by plastic latches, and if you are going to use both components in some other way, do not apply much force - a piece of plastic can easily break off and the seal of the light bulb body will be broken.
Having opened the case, carefully disconnect the contacts going from the ballast to the filaments in the bulb, because they block full access to the board. Often they are simply attached to the pins, and if you no longer plan to use the failed bulb, you can safely cut off the connecting wires. As a result, you should see something like this.
Disassembling the lamp
It is clear that lamp designs from different manufacturers may differ in “filling”. But the general scheme and basic constituent elements have much in common.
Then you need to carefully inspect each part for swelling, breakdowns, and make sure that all elements are soldered securely. If any of the parts has burned out, it will be immediately visible by the characteristic soot on the board. In cases where no visible defects are found, but the lamp is not working, use a tester and “ring” all elements of the circuit.
As practice shows, resistors, capacitors, and dinistors most often suffer due to large voltage drops, which occur with unenviable regularity in domestic networks. In addition, frequent flicking of the switch has an extremely negative effect on the operating time of fluorescent light bulbs.
Therefore, in order to extend their service life for as long as possible, try to turn them on and off as little as possible. The pennies saved on electricity will ultimately result in hundreds of rubles to replace a burnt-out light bulb ahead of time. .
Disassembled lamps
If, as a result of the initial inspection, you have identified scorch marks on the board, swelling of parts, try replacing the failed units by taking them from other non-working donor bulbs. After installing the parts, “ring” all the components of the board with the tester again.
By and large, from the ballast of a non-working fluorescent light bulb, you can make a switching power supply with a power corresponding to the original power of the lamp. As a rule, low-power power supplies do not require significant modifications. But, of course, you will have to work hard on blocks of higher power.
To do this, you will need to slightly expand the capabilities of the original inductor by providing it with additional winding. You can regulate the power of the power supply being created by increasing the number of secondary turns on the inductor. Want to know how to do it?
Preparatory work
As an example, below is a diagram of a Vitoone fluorescent light bulb, but fundamentally the composition of the boards from different manufacturers does not differ much. In this case, a light bulb of sufficient power is presented - 25 watts; it can make an excellent 12 V charging unit.
Vitoone 25W lamp diagram
Power supply assembly
The lighting unit (i.e., a bulb with filaments) is indicated in red in the diagram. If the threads in it have burned out, then we will no longer need this part of the light bulb, and we can safely bite off the contacts from the board. If the light bulb was still burning before the breakdown, albeit dimly, you can then try to revive it for a while by connecting it to working diagram from another product.
But that’s not what we’re talking about now. Our goal is to create a power supply using ballast taken from a light bulb. So, we delete everything that is between points A and A´ in the above diagram.
For a power supply of low power (approximately equal to the original one of the donor light bulb), only a small alteration is enough. A jumper must be installed in place of the remote lamp assembly. To do this, simply wind a new piece of wire to the freed pins - at the place where the former filaments of the energy-saving light bulb were attached (or to the holes for them).
In principle, you can try to slightly increase the generated power by providing additional (secondary) winding to the inductor already on the board (it is designated in the diagram as L5). Thus, its native (factory) winding becomes the primary one, and another layer of the secondary one provides that same power reserve. And again, it can be adjusted by the number of turns or the thickness of the wound wire.
Connecting the power supply
But, of course, it will not be possible to significantly increase the initial capacity. It all depends on the size of the “frame” around the ferrites - they are very limited, because originally intended for use in compact lamps. Often it is possible to apply turns in only one layer; eight to ten will be enough to start with.
Try to apply them evenly over the entire ferrite area to obtain maximum performance. Such systems are very sensitive to the quality of the winding and will heat up unevenly and eventually become unusable.
We recommend that you remove the inductor from the circuit during the work, since otherwise it will not be easy to wind it. Clean it of factory glue (resins, films, etc.). Visually assess the condition of the primary winding wire, check the integrity of the ferrite. Since if they are damaged, there is no point in continuing to work with it.
Before starting the secondary winding, lay a strip of paper or electrical cardboard along the top of the primary winding to eliminate the possibility of breakdown. Adhesive tape in this case is not the best the best option, since over time the adhesive composition ends up on the wires and leads to corrosion.
The circuit diagram of the modified light bulb board will look like this
Scheme of a modified light bulb board
Many people know firsthand that winding a transformer with their own hands is a pleasure. This is more of an activity for the diligent. Depending on the number of layers, this can take from a couple of hours to a whole evening.
Due to the limited space of the choke window, we recommend using varnished copper cable with a cross-section of 0.5 mm to create the secondary winding. Because there is simply not enough space for the insulated wires to wind any significant number of turns.
If you decide to remove the insulation from an existing wire, do not use a sharp knife, because... After the integrity of the outer layer of the winding is damaged, one can only hope for the reliability of such a system.
Drastic changes
Ideally, for the secondary winding you need to use the same type of wire as in the original factory version. But often the “window” of the choke magnetic receiver is so narrow that it is not possible to even wind one full layer. And it is also necessary to take into account the thickness of the gasket between the primary and secondary windings.
As a result, it will not be possible to radically change the power output by the lamp circuit without making changes to the composition of the board components. In addition, no matter how carefully you carry out the winding, you will still not be able to make it as high quality as in factory-produced models. And in this case, it is easier to assemble a pulse unit from scratch than to remake the “good” obtained for free from a light bulb.
Therefore, it is more rational to look for a ready-made transformer with the required parameters at the disassembly of old computer or television and radio equipment. It looks much more compact than a “homemade” one. And its safety margin cannot be compared.
Transformer
And you won’t have to rack your brains over calculating the number of turns to obtain the desired power. Soldered to the circuit - and you're done!
Therefore, if you need more power from the power supply, say about 100 W, then you will have to act radically. And only the spare parts available in the lamps cannot be used here. So, if you want to further increase the power of the power supply, you need to unsolder and remove the original inductor from the light bulb board (indicated in the diagram below as L5).
Detailed UPS diagram
Connected transformer
Then, in the section between the previous location of the choke and the reactive midpoint (in the diagram, this section is located between separating capacitors C4 and C6), a new powerful transformer is connected (designated as TV2). If necessary, an output rectifier is connected to it, consisting of a pair of connecting diodes (they are designated in the diagram as VD14 and VD15). It wouldn’t hurt to simultaneously replace the diodes on the input rectifier with more powerful ones (in the diagram these are VD1-VD4).
Don't forget to also install a larger capacitor (shown in the diagram as C0). It must be selected at the rate of 1 microfarad per 1 W of output power. In our case, a 100 mF capacitor was taken.
As a result, we get a completely capable switching power supply from energy saving lamp. The assembled circuit will look something like this.
Test run
Test run
Connected to the circuit, it serves as something akin to a stabilizer fuse and protects the unit during current and voltage fluctuations. If everything is good, the lamp does not particularly affect the operation of the board (due to low resistance).
But during high current surges, the lamp resistance increases, leveling out the negative impact on the electronic components of the circuit. And even if the lamp suddenly burns out, you won’t feel as sorry for it as a self-assembled pulse unit that you’ve been poring over for several hours.
The simplest test circuit diagram looks like this.
After starting the system, observe how the temperature of the transformer (or the inductor wound with the “secondary”) changes. If it starts to get very hot (up to 60ºC), de-energize the circuit and try replacing the winding wires with an analogue with a larger cross-section, or increase the number of turns. The same applies to the heating temperature of transistors. If it increases significantly (up to 80ºС), each of them should be equipped with a special radiator.
That's basically it. Finally, we remind you to follow safety rules, since the output voltage is very high. Plus, the components of the board can get very hot without changing in any way externally.
We also do not recommend using such pulse units when creating chargers for modern gadgets with fine electronics (smartphones, electronic watches, tablets, etc.). Why take such a risk? No one can guarantee that a “homemade product” will work stably and will not ruin an expensive device. Moreover, there is more than enough suitable stuff (meaning ready-made chargers) on the market, and they are quite inexpensive.
Such a homemade power supply can be safely used to connect light bulbs different types, for powering LED strips and simple electrical appliances that are not so sensitive to current (voltage) surges.
We hope you were able to master all the material provided. Perhaps it will inspire you to try creating something similar yourself. Even if the first power supply you make from a light bulb board will not be real at first working system, but you will acquire basic skills. And most importantly – passion and thirst for creativity! And then, you see, you’ll be able to make a full-fledged power supply for LED strips, which are very popular today, from scrap materials. Good luck!
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Energy-saving lamps were actively positioned as a replacement for low-efficiency and unreliable incandescent lamps. The gradual decline in prices for “housekeepers” has led to their becoming almost ubiquitous.
The biggest disadvantage of LEDs is their high cost. It is not surprising that many are converting energy-saving lamps into LED lamps, using the available and inexpensive element base to the maximum.
Theoretical background
LEDs operate at low voltage - about 2-3V. But most importantly, for normal operation What is required is not voltage stability, but current stability, flowing through them. When the current decreases, the brightness of the glow decreases, and an excess leads to failure of the diode element. Semiconductor devices, which include LEDs, have a pronounced temperature dependence. When heated, the junction resistance drops and the forward current increases.
A simple example: a stable voltage source produces 3V, with a LED consumption current of 20mA. As the temperature rises, the voltage on the LED remains unchanged, but the current increases up to acceptable values.
To eliminate the described situation, semiconductor light sources are powered from a current stabilizer, also known as a driver. By analogy with fluorescent lamps, the driver is sometimes called a ballast for LEDs.
The presence of an input voltage of 220V, together with the requirement for current stabilization, leads to the need to create a complex power supply circuit LED lamps.
Practical implementation of the idea
The simplest power supply for LEDs from a 220V network is as follows:
In the figure shown, the resistor provides a drop in excess supply voltage, and a diode connected in parallel protects the LED element from voltage pulses of reverse polarity.
As can be seen from the figure, which can be verified by calculations, a high-power damping resistor is required, which generates a lot of heat during operation.
Below is a diagram where a quenching capacitor is used instead of a resistor
Using a capacitor as a ballast allows you to get rid of a powerful resistor and increase the efficiency of the circuit. Resistor R1 limits the current at the moment the circuit is turned on, R2 serves to quickly discharge the capacitor at the moment it turns off. R3 further limits the current through the group of LEDs.
Capacitor C1 serves to dampen excess voltage, and C2 smoothes out power ripples.
The diode bridge is formed by four 1N4007 type diodes, which can be removed from an unusable energy-saving lamp.
The circuit calculation was made for HL-654H245WC LEDs with an operating current of 20mA. It is possible to use similar elements with the same current.
Just like in the previous circuit, current stabilization is not provided here. To prevent LED failure, ballast circuit for LED lamps, the capacitance of capacitor C1 and the resistance of resistor R3 are selected with a margin so that at maximum input voltage and elevated temperature LEDs, the current through them did not exceed the permissible values. In normal mode, the current through the diodes is slightly less than the nominal one, but this has virtually no effect on the brightness of the lamp.
The disadvantage of such a scheme is that the use of more powerful LEDs will require an increase in the capacity of the quenching capacitor, which has large dimensions.
Nutrition is done in the same way. LED strip from the board of an energy-saving lamp. It is important that the current of the LED strip matches the line of LEDs, that is, 20mA.
We use an energy-saving lamp driver
The circuit is more reliable when a driver made from an energy-saving lamp is used with minimal modifications. As an example, the figure shows the conversion of a 20W energy-saving lamp to power a powerful LED with a current consumption of 0.9A.
Converting an LED lamp to power LEDs The modification of the electronic ballast for LED lamps in this example is minimal. Most of the elements in the circuit are left over from the old lamp driver. The L3 inductor has been modified and a rectifier bridge has been added. In the old circuit, a fluorescent lamp was connected between the right terminal of capacitor C10 and the cathode of diode D5.
Now the capacitor and diode are connected directly, and the inductor is used as a transformer.
Remaking the inductor consists of winding a secondary winding, from which the voltage will be removed to power the LED.
Without disassembling the inductor, you need to wind 20 turns of enameled wire with a diameter of 0.4 mm around it. When turned on, the open circuit voltage of the newly completed winding should be about 9.5–9.7V. After connecting the bridge and the LED, the ammeter connected to the power supply of the LED element should show about 830–850 mA. A larger or smaller value requires correction of the number of turns of the transformer.
Diodes 1N4007 or similar can be used from another faulty lamp. Diodes in housekeepers are used with a large current and voltage reserve, so they rarely fail.
All of the above LED driver circuits from an energy-saving lamp, although they provide low-voltage power, have a galvanic connection to the AC network, so precautions must be taken when debugging.
The best and safest would be to use a separating transformer with identical primary and secondary windings. Having the same 220V at the output, the transformer will provide reliable galvanic isolation of the primary and secondary circuits.
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.
Eliminating these shortcomings in pulse blocks power supply, 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 constant pressure into rectangular pulses, with a frequency from 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 on a high-voltage filter 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:
- a temporary winding is wound onto the inductor, approximately 10 turns of any wire;
- connected to a load resistor with a power of at least 30 W and a resistance of approximately 5-6 Ohms;
- connect to the network, measure the voltage at the load resistance;
- divide the resulting value by the number of turns to find out how many volts there are per 1 turn;
- 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. The primary winding with PEL wire - 0.85 mm 2 has 63 turns, and the two secondary windings with the same wire have 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:
- The first test run should be carried out after incandescent lamp 100 W to limit the current to the power supply.
- Be sure to connect a 3-4 Ohm load resistor with a power of 50-60 W to the output.
- 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.
REPAIR AND ALTERATION OF ENERGY-SAVING LAMPS
ENERGY SAVING LAMP FROM 12V
I wound it by eye and from memory, interpreting the size of the cores according to the continuous winding scheme. First, I wound the collector winding with 10 turns with 0.4mm wire, the second base winding with 6 turns with 0.2mm wire, laid a layer of insulation and overlapped the load winding with 0.1 wire, it turned out to be about 330-340 turns. I connected a lamp from a 7w scanner to the load, the device immediately started working, as evidenced by the light emanating from the lamp. Nearby lay a 13-watt energy-saving lamp with a burnt-out spiral, I decided to try to make this brainchild cope with such a load, I was pleasantly surprised, with a current of half an ampere at a voltage of 12 volts, the lamp shines quite brightly.
It also works from two lithium-ion batteries, although consuming 150 mA more. I soldered it together using a hinged assembly (4 parts) and all this was miraculously housed in the original 220 ballast housing.
The transistor does not get very hot; after five minutes of operation, you can hold your finger on it. Now this design will go straight to the dacha, where, as usual, there are constant power outages, you can drink tea or make your bed in daylight.
What can you do if your compact fluorescent lamp burns out?
Although, depending on the manufacturer, economy lamps have a warranty of up to 3 years. But consumers may be faced with the fact that the light bulb has burned out, and you do not have the packaging, the purchase receipt, or the store has moved to another location, i.e., for some reason beyond your control, you cannot exchange the broken item. We decided to invite you to use original solution on the use of burnt-out economy lamps, which we found on the vast Internet resource and offer it to you.
Remember, you are putting your life in danger by being exposed to 220V voltage!
The easiest way is to throw it in the trash, but you can make… another one out of it, and if you have accumulated several burnt out lamps, then you can do…. repairs.
If you have held a soldering iron in your hands at least once, then this article is for you.
You can make your own electronic ballast for fluorescent lamps and turn on the lamp up to 30 watts, without a starter or choke, using a small scarf removed from our economy lamp. At the same time, it will light up instantly; when the voltage drops, it will not ‘Blink’.
This lamp burns out in two ways:
1) electronic circuit is on
2) the filament burns out
First, let's find out what happened. We disassemble the lamp (very often assembled with latches, cheaper options are glued together).
Turn off the flask, bite off the power wires:
We call the glow of the flask (to decide whether to throw away the flask or not)
I was unlucky, both filament coils burned out (for the first time in my considerable practice, usually one, and when the circuit burns out, not even one). In general, if at least one flask burns out, we throw it away; if not, then it is working, and the circuit burned out.
We debug the working flask for storage (until the next burnt housekeeper) and then attach the flask to the working circuit. So out of several we make 1, or maybe more (depending on your luck).
And here is an option for making a fluorescent lamp. You can connect it like a 6 Watt lamp from a “Chinese” lantern (for example, I wrapped it with plastic from a green bottle, and hid the circuit in a burnt charger, from mobile phone and it turned out to be a cool backlight for an aquarium) and a 30 Watt fluorescent lamp:
Can electronic ballast be repaired?
Fluorescent lamps with electronic ballast can be found everywhere today. Table lamps with rectangular shades and a two-arm holder are very popular. All electrical goods stores already sell lamps that are screwed into regular sockets with a round thread instead of classic incandescent lamps. In particular, the St. Petersburg metro has recently completely gotten rid of incandescent lamps, replacing them with fluorescent ones. The advantage of such lamps is obvious - long service life, low power consumption with high light output (suffice it to say that an 11-W fluorescent lamp replaces a 75-W incandescent lamp), soft light with a spectrum close to natural sunlight.
The leading manufacturers of fluorescent lamps are Philips, Osram and some others. Unfortunately, on the domestic market there are plenty of low-quality Chinese lamps that break down much more often than their branded counterparts. A detailed story about electronic ballasts, operating principles, advantages, and circuit solutions can be found in the book “Power Electronics for Professionals and Amateurs.” The section of the book is called "Ballast that won't drown you. New methods of controlling fluorescent lighting lamps." Therefore, readers who need to get the initial
information about electronic ballasts, you can refer to the book, but here we consider a rather specific issue of repairing lamps that have failed.
The history of this article is connected with the author’s acquisition of a lamp from an unknown company (photo 1). This lamp worked flawlessly in the chandelier for several months, but after this time it simply stopped lighting. There was nothing left to do but disassemble the lamp by carefully (from the sides) prying up the housing with a thin screwdriver (it consists of two halves, fastened together by three protrusions-latches).
The disassembled lamp is shown in photo 2. It consists of a round base, a control circuit (the electronic ballast itself) and a plastic circle into which a tube is glued that produces light. When disassembling the lamp, care should be taken so that, firstly, not to break the cylinder and not to damage your hands, eyes and other parts of the body, and secondly, not to damage the electronic circuit (do not tear off the “tracks”) and the housing (plastic) .
Research carried out using a multimeter showed that one filament in the lamp cylinder had burned out. Photo 3, which was taken after opening the cylinder, shows that the spiral has burned out, darkening the phosphor in the surrounding area. It was assumed that nothing had happened to the electronic ballast (this was later confirmed). With a high degree of confidence, we can say that the lamp filament is the weakest point, and in the vast majority of lamps that have failed, filament burnout will be observed rather than burnout of the electronic part of the circuit.
By the way, about electronic circuit electronic ballast. It is shown in photo 4. The circuit is redrawn from the printed circuit board. In addition, it does not show some elements that do not affect the basic operation of the ballast, and also does not show the ratings. The lamp ballast is a push-pull, half-bridge type oscillator with a saturable transformer. Such a self-oscillator is well described in books and does not require additional explanation. A diode bridge VD1-VD4 with filter C1, C2, L1 is installed at the input. Capacitor C1 prevents the penetration of high-frequency interference into the supply network, capacitor C2 serves as a network ripple filter, inductor L1 limits the inrush current and filters high-frequency interference. Inductor L2 and capacitor C3 are elements of a resonant circuit, the voltage in which “lights” the lamp. Capacitor C4 is the starting capacitor. It is clear that if one of the filaments breaks, the lamp will no longer light up.
A very important element of the circuit is fuse F1. If something happens in the electronic ballast circuit (for example, the transistors of the half-bridge “burn out”, creating a “through” current, or the capacitor C1, C2 breaks down, or the diode bridge breaks down), the fuse will protect the network from short circuit and possible fire. Photo 5 shows this fuse.
It is a cone without a classic holder with long leads, one of which is soldered to the base, and the other to printed circuit board ballast. So if the fuse is blown, most likely something has happened in the ballast circuit, and its elements need to be checked. And if not, the ballast is probably intact.
The most interesting thing is that such an energy-saving lamp can be repaired, and it will cost less than purchasing a new lamp. It will look, of course, not as beautiful as an industrial one, but quite decent (if everything is done carefully). So, you need to purchase a replacement element for a table lamp, for example, such as shown in photo 6. The manufacturer of this lamp is the Italian company Osram, the lamp power is 11 W, which corresponds to 75 W of an incandescent lamp.
On the lamp box there is interesting information about the power consumption of other lamps, as well as reliability. This 9 W lamp will replace a 60 W incandescent lamp, 9 W will replace a 40 W incandescent lamp, and 5 W will replace a 25 W incandescent lamp. The guaranteed time between failures is 10,000 hours, which corresponds to 10 incandescent lamps. This is approximately 13 months of continuous work. The dump base should contain four pins, that is, two spirals (photo 7). In this lamp, the right two terminals belong to one spiral, the left two - to another spiral. If the location of the spirals is not obvious, you can always find the necessary leads using a multimeter - the spirals have a low resistance of the order of several ohms.
The lamp leads must be carefully tinned with solder, avoiding overheating.
Now let's prepare the base to which we will attach the lamp. A circle similar to the existing one, filled with white mass (photo 8), needs to be made a new one and a file is used to prepare the area to which the lamp will be glued (photo 9). It is strictly not recommended to break the lamp bulb.
Next, it’s better to check how the lamp lights up. We solder the lamp leads to the ballast (photo 11) and plug the ballast into the network. To break in, it is worth training it by turning it on and off several times and keeping it on for several hours. The lamp glows quite brightly, and at the same time heats up, so it is better to put it on a board and cover it with a fireproof sheet. When the training is completed, we disassemble this structure and begin installing the lamp.
Take a tube of Moment superglue and apply a few drops to the mating surfaces. Then we insert the leads into the holes and press the parts tightly against each other, keeping them in this form for half an hour. The glue will securely “grab” the parts (photo 10). It is better to use this glue or dichloroethane, since for reliable fastening the plastic in the mating area must melt a little.
All that remains is to assemble the lamp. We solder the ballast into the base, not forgetting the fuse. In advance (before soldering), you need to solder four wires that will connect the lamp to the ballast. Any wire will do, but it’s better if it’s an MGTF type wire in fluoroplastic heat-resistant insulation (photo 12). Assembling the lamp is also simple - just lay the wires inside the base, or twist them with a rope, and then snap the latches. For electrical safety purposes, it is better to seal the holes from the previous cylinder with circles cut from dairy product packaging.
The repaired lamp is ready (photo 13). It can be screwed into the cartridge.
In conclusion, I note that you can fantasize quite widely on the topic of electronic ballasts. For example, insert a lamp into a beautiful lamp and hang it from the ceiling using parts from a burnt lamp.