The New Year is coming soon! Christmas tree decorations appear on store shelves next to tangerines, sweets and champagne: colorful balls, tinsel, all kinds of flags, beads and, of course, electric garlands.
The usual garland of multi-colored light bulbs, perhaps, and not buy. But the various flashing lights, mainly made in China, simply do not count. Microscopic light bulbs can be placed on a piece of cardboard or woven into a carpet of wires that can be used to decorate an entire window at once.
Christmas tree garlands are also distinguished by a great variety, primarily in external decoration and design. The cost of such garlands is low, as is, in fact, the power of the bulbs.
Most of the lights have a small plastic box with one button, a cord with a power plug, and wires that go to a string of colored lights. Garland decoration can be very diverse.
The simplest and cheapest option consists of microscopic light bulbs inserted. The back of the shipping box contains instructions for replacing bulbs and safety instructions, although there are no replacement bulbs included. These are the garlands that are sold in the chain of stores "All at 38", however, recently they have already cost forty rubles.
Figure 1. Garland for forty rubles
Garlands of a different style have small plastic shades on the bulbs, for example, in the form of transparent flowers with petals. But the box with the button remains the same, although the price of the garland reaches two hundred rubles. Let's try to open the box and see what's inside.
Figure 2. External view of a garland controller with three thyristors
At the bottom of the figure, two wires are shown; this is just the connection of the device to the network. There is also a button with which the operating modes are switched. At the top you can see three thyristors and wires leading to the garlands.
In the middle of the board is, - such a black blob installed on a small printed circuit board. The board has contact pads with which the controller is soldered into the main board.
How many thyristors are on the board
The control electrodes of the thyristors are connected to the outputs of the microcontroller, which include garlands of light bulbs. The microcontroller has four outputs, but often, instead of four thyristors, only three are installed on the board, and in some cases only two.
The necessary visual effect is achieved by connecting the garlands and the arrangement of the bulbs: bulbs of two or even three colors are sealed in one garland. Just such a board is shown in Figure 2.
If you look at this board from the printed wiring side, you can see that three thyristors are soldered, and under the fourth there are holes with tinned contact pads, as shown in Figure 3. In some cases, the holes are not even drilled, they say, whoever wants to, he will drill himself ...
Figure 3. Daisy chain controller board. Free space for thyristor
Here you should note the following feature: if the controller output is not connected anywhere, this does not mean at all that it is inoperative. The program in all controllers is flashed, apparently, the same, all controller outputs are involved.
This is easy to verify with the help of an arrow tester. If you measure the constant tension on the free leg, then the arrow will jump, twitch and deflect along with the blinking of other garlands. It is enough just to solder the missing thyristor into the board, and, please, we get a full-fledged four-channel garland.
The thyristor can be taken from an old faulty board (it happens that the controller becomes unusable) or for forty rubles you can buy an additional garland and remove the thyristor from there. Costs are negligible for a good business!
Garland schematic diagram
It is easy to draw up a schematic diagram using a printed circuit board. There are two types of schemes, slightly different from each other. The first, most advanced version is shown in Figure 4.
Figure 4. The controller of the Chinese garland. Option 1
The entire circuit is powered through VD1 ... VD4. The garlands are supplied with a pulsating voltage and are switched on by the controller through the thyristors VS1 ... VS4. Resistor R1 and microcontroller DD1 form a voltage divider, at the output of which a voltage of 12V is obtained.
Capacitor C1 smooths out the ripple of the rectified voltage. Through the resistor R7, the mains voltage is fed to the input of the controller 1 to synchronize the circuit with the 220V mains frequency, which allows phase control of the thyristors. This synchronization allows for smooth lighting and fading of the lights. Such boards can be found in expensive garlands.
The board shown in Figure 3 is assembled according to a somewhat simplified diagram, which is shown in Figure 5.
Figure 5. The controller of the Chinese garland. Option 2
It is immediately striking that there are only three thyristors, and only one diode remains from the rectifier bridge. Resistors from thyristor control electrodes also disappeared. But, in general, the consumer properties remained the same as in the previous circuit, despite the fact that the lamps are lit only when there is a positive half-cycle of the mains voltage on the upper wire of the circuit. Half-wave rectification is obtained without a rectifier bridge.
This version of the circuit design is inherent in those garlands that are "all forty". That, in fact, is all that can be said about the circuitry of Chinese Christmas tree garlands.
How to connect powerful lamps
The power of the garlands is low, the bulbs are just microscopic, except for a home tree, they are unlikely to go anywhere else. But sometimes it is required to connect a garland with powerful incandescent lamps, for example, for decorative illumination of building facades. Such a refinement has already been given in the article. A diagram of the modified garland is shown in Figure 8 in the mentioned article.
If you don't want to redo the board
It is much easier to do without reworking the controller board. All you have to do is make four powerful output switches with optocouplers and connect them instead of low-power strings. The power switch circuit is shown in Figure 6.
Figure 6. Powerful power switch with optocoupler isolation
Actually, the scheme is typical, it works flawlessly, it does not contain any pitfalls. As soon as the LED of the MOC3021 optocoupler lights up, a low-power optocoupler thyristor opens and the control electrode and the anode of the BTA16-600 triac are connected through pins 4, 6 and resistor R1. The triac opens and turns on the load, in this case a garland.
The optocoupler should be used without a built-in CrossZero circuit (line voltage zero crossing detector), for example, MOC3020, MOC3021, MOC3022, MOC3023. If the optocoupler has a CrossZero node, then the circuit WILL NOT WORK! This should not be forgotten.
Triac BTA16-600 has the following parameters: forward current 16A, reverse voltage 600V. With a current of 5A and a voltage of 220V, the load power is already a whole kilowatt. True, you will need to install a triac on the radiator.
The metal substrate is isolated from the crystal, as indicated by the letter A in the triac marking. This makes it possible to install triacs on a radiator without mica gaskets and insulators for the screw. By the way, it is these triacs that are in the power regulators of household vacuum cleaners, while the radiator is blown by the air flow at the outlet of the vacuum cleaner.
If the load power is not more than 400W, then you can do without a radiator. The pinout of the triac is shown in Figure 7.
Figure 7. BTA16-600 triac pinout
This figure will not be superfluous at all when assembling the power switch circuit. All four power switches are best assembled on a common printed circuit board. Resistor R is best assembled from two 2W resistors to avoid overheating. The maximum current of the input LED of the optocoupler is 50mA, therefore a current of 20 ... 30mA will ensure its long-term trouble-free operation.
Figure 8. Connecting power switches to the controller board
In general, everything is clear and simple. Garlands are soldered from the controller, and instead of them the input circuits of the power switches are soldered. This does not require any intervention on the printed circuit board of the controller. The only exception is soldering an additional thyristor, provided that it can be found. You will also have to slightly power the power cord with a plug, since the original one has a very small cross-section.
With proper installation and serviceable parts, the circuit does not need to be adjusted. The design of the device is arbitrary, best of all in a metal case of suitable dimensions, which will act as a radiator for the triacs.
In order to ensure electrical safety, the device should be switched on through a circuit breaker, or at least a fuse.
How to repair a Christmas garland
New Years is soon! Fir-trees, toys, all kinds of lights ... cheer up. But how “happy” is the situation when we take a brilliant invention of mankind - a Christmas tree electric garland, plug it into the network, but it does not work in whole or in part. What to do?
The easiest way to solve the problem is to go buy a new garland! But if you do not want to spend money, believe in your strength and patience, then you can try to become a "resuscitator" of the New Year's beauty.
Let's start with what we remember: the simplest garland consists of a certain number of light bulbs connected in series
With this connection, the operating voltage of the consumers is summed up. And we can, for example, plug 55 bulbs, designed for a voltage of 6 V each, into a network with a voltage of 220 V. But if at least one of them burns out, the whole circuit is opened.
How to find a problem spot in a garland?
Here you can act methodically and consistently. Then, in the worst case, in the above example, you would have to test 54 bulbs. This is a lengthy process, especially in the case of inspecting non-separable strings (the modern Chinese version is "disposable").
A different method will be more effective and efficient. The garland is divided into two parts and the faulty one is determined. The decreasing part with a break is divided into two more parts, of which the faulty one is determined, and so on until the break is found. This method will be optimal, since it assumes the minimum number of measurements.
A few practical tips when repairing a garland.
When detecting a break in non-separable garlands, you can use a tester with probes to which ordinary sewing needles are attached. Without removing the insulation from the wire, you pierce it with a needle and get to the "core" of the conductor.
In the case of repairing a garland with an electronic control unit, you should pay attention to the fact that it consists of several (usually from 1 to 4) sections connected to its own control channel.
If none of the sections of the garland works, then first of all, you should check the power cord to the control unit, and then the common wire for all "branches" of the garland. Failure of the control unit itself is possible. In this case, it is better to buy a new garland.
If you find a burned-out light bulb in a non-separable garland, then you can replace it like this: short-circuit the wires near its contacts. That is, "short-circuit" it. The electric current will bypass the light bulb, and the garland will be saved.
ATTENTION! Do not overuse this way. This method can be applied 1-2 times in one branch of a garland of at least 50 bulbs. Otherwise, each of the remaining working lamps will experience overvoltage, which will significantly reduce the duration of the garland.
Go for it! Better to drink a new high-quality New Year's garland! You need to start the New Year with new things!
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Garland Ek-04 scheme, mini controller EK-04, EK - 04, repair of garland EK-04, ek-04 mini controller fix, ek-04 controller connection, EK 04 wiring diagram, ek-04 repair, circuits mini controller ek-04, PROGRAMS mini kontroller ek-04 datasheetSubscribe to the information in social media, dyakuumo for the popularization of the portal:
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To favoritesFM radio transformer controlled by Arduino Nano - for the most advanced and purposeful. The radio transformer allows you to show both technical and creative abilities, since a teenager can create his own author's design of a radio receiver. FM radio is assembled from ready-made modules, each of which is a complete device. Soldering of 2 points is required (jumper). The EK-004A set will allow you to get acquainted with the principles of building arduino-controller systems using the example of a working model of an FM radio receiver. The Arduino Nano module is supplied already "wired", so even a user who does not understand anything in programming, having connected all the components of the kit together according to the attached detailed instructions, in 10 minutes will receive a working radio receiver. But, of course, the radio is just a demonstration of one of the many options for devices that a user can develop based on the supplied Arduino Nano controller.
Additional Information
Detailed description
Any modern electronic device has a "brain center" called a controller. The controller receives electrical signals from sensors and controls, processes them in accordance with the program embedded in it and issues control commands to external executive devices (indicators, relays, motors, sound modules, etc.).
One and the same controller can be adapted to perform a variety of tasks, just write a control program and use the appropriate I / O modules. Thus, the development time for a new device is sharply reduced. This approach to development is the de facto standard of today, and therefore it is desirable for every radio amateur, if not to move in this direction, then at least to be well versed in it, developing the skills of not only a "solder", but also a programmer.
Currently, the universal Arduino controller, which has undeniable advantages, is gaining more and more popularity among radio amateurs:
An easy-to-learn programming language based on C / C ++;
No need for a separate programmer (the Arduino module already has a built-in bootloader that allows you to program the module via a USB connector, with which it is connected directly to the computer);
The Arduino project is completely open, there are a huge number of sites on the Internet with ready-made projects and schemes;
Arduino modules have a standard pinout, which simplifies the integration of modules with external I / O cards ("shields").
A set of Arduino-compatible modules Master Kit EK-004A.
Assembled radio designer.
Don't be afraid to ruin something! You can always download the original firmware EK-004A from the Master Kit website
Among the many lighting fixtures used to decorate Christmas trees, the Chinese garland scheme occupies a special place. She, like all similar Chinese products, is simple and cheap. There is a lot of controversy about the reliability of such garlands, however, most consumers use them.
Classical Chinese garland diagram
This design is equipped with smooth brightness control. For this, phase control is used, which regulates the opening angle of the thyristors. Automation uses as many as eight programs providing a wide variety of control algorithms. Due to its qualities, the device is very cheap, therefore it is sold in millions of copies.
The controller is based on a small board, where space is provided. A microcontroller with four outputs is also located here. It is a small piece of genitax, where a microchip is attached using epoxy resin. Four thyristors are controlled through the outputs of the microcontroller using current-limiting resistors. This device is designed for anode voltage up to 600 volts and a current in the range of 0.6-0.8 amperes. In some designs of cheap garlands, instead of the input diode bridge, one diode remains. At the same time, the connection of the electrodes that control the thyristors is carried out directly to the outputs of the microcontroller, without limiting the current.
As a rule, the power of the microcontroller is very small, therefore, it is not able to control the operation of powerful triacs. In order to solve this problem, it is necessary to use a separate low-power power supply that is galvanically isolated from the mains. For these purposes, you can use a low-power adapter, for example, one that feeds a TV antenna amplifier, which contains a stabilizer in its circuit.
Other ways to solve problems
To combine a low-power microcontroller with powerful triacs, the use of transistor switches is practiced, where transistors with a high current gain are used. Thus, the Chinese garland circuit does not overload the outputs of the microcontroller. To ensure galvanic isolation, special microcircuits are used, the input of which contains an LED, and a low-power triac is installed at the output.
In order for the Chinese garland to work normally, it must be synchronized with the network using a signal. For this purpose, a phase with a nominal value of 220 volts is fed to the microcontroller input through the installed resistor. The neutral wire of the network, connects to the common wire of the entire device.
Replacing the control unit of the Chinese garland
Almost every family has a broken Chinese New Year garland in need of repair. December always comes and catches families by surprise, who, just the day before, decide to put up a New Year tree and decorate it with beautiful garlands.
As a rule, we find out that the Chinese garland needs repair at the wrong moment. On a new thing, it is not a hunt to spend money at all, but not everyone can manage to repair the Chinese New Year miracle on their own.
Now we will look at how a simple Chinese garland with adjustable frequency of luminescence works, common malfunctions, methods for finding a breakdown and how to fix them. In the article, everything will be described in detail, clearly shown in the photographs. Everything will be convenient for restoring its performance on its own. To cope with such a repair will be within the power of almost every person.
Christmas garland patterns
Serial connection of paws
To begin with, consider the simplest scheme of a New Year's garland. This series connection of incandescent bulbs, in the Soviet years, was the most common scheme. Every house had a similar garland.
In a serial connection, all bulbs are connected in a chain, in a wire break and connected to a power source, generator, household wiring, battery. In this case, the same current flows throughout the garland.
It didn't smell there, of course. Starters filmed at school with fluorescent lamps made her blink. The starters were simply connected to the circuit, similar to light bulbs, in series.
A few words about starters and their meaning. It is a simple gas discharge lamp housed in an aluminum, paper, or plastic housing. For convenience, an inspection hole has been made in the body.
It consists of two bimetallic electrodes, which, bending from the passing current, close and open the electrical circuit. After that, the Christmas tree garland began to blink rather quickly.
This scheme is very simple and convenient, but it has a significant disadvantage. When one light bulb burns out, the electrical circuit is broken and the whole garland goes out.
Parallel connection
Modern Chinese Christmas tree garlands are included in a parallel electrical circuit. By doing this, they extend the life of the garland and postpone repairs for a long time.
The whole thing is that with a parallel connection of bulbs in a Christmas tree garland, the voltage remains the same on each element of the circuit. What gives a lot of advantages, the main thing is that when any light bulb in the circuit burns out, it does not break and the garland continues to work. As for the current strength, it is different for each element of the circuit.
This scheme is most common in home electrical wiring, due to its reliability, convenience and ease.
The main malfunctions of New Year's garlands
We simulate the situation, you take out your Christmas tree decorations and New Year's garlands from the closet, start decorating the Christmas tree, plug it in, and nothing happens. Disappointment and despair on the faces of your children, faith in New Year's magic disappears, the holiday was not a success.
It is still possible to fix everything, even if there is fifteen minutes of backwardness before the chimes, with the help of your own forces and an uncomplicated instrument.
The garland shows no signs of activity at all. We look at the electrical plug, nicknamed its integrity by the device. To do this, we disassemble the control unit of the Chinese garland, and look at the contacts that come from the electrical plug.
We put the switch in the measurement of diodes, we press one probe to any contact of the plug, and the second we apply to the contact of the wire on the control unit board. If the device emits a squeak, then the wire is working, if not, then it is broken. With the second contact, we do the same. Both turned out to be intact, we are looking for the malfunction further, if one is open, we change this part of the wire together with the plug, and turn it on again. Lights up normally, we are glad, no, we search further.
A small addition, the control unit for the blinking cycles of the Chinese garland, is located on the wire, immediately after the plug. This is the green box with a button, by clicking on which, you change the blinking frequency of the New Year.
How to check a light bulb from a garland
If the garland is made with a series connection of light bulbs, then, most likely, one of the lamps has burned out. The electrical circuit is open, and current can only flow in a closed circuit.
To restore the performance of a Chinese New Year's toy, you just need to replace the damaged element. But, first you need to check the light bulb, which is under suspicion.
You can check by visual inspection, the easiest way, in a glass vacuum cylinder, is a filament spiral. When the current passes through the spiral, it begins to glow in the spectrum visible to our eyes. If it is burned out, it will be visible not with an armed eye.
You can check it with a tester, for this we put the switch in the resistance measurement mode. We connect the probes to the electrodes of the incandescent lamp, and look at the display of the digital tester. A working lamp from a garland should have a resistance, and quite large, if it is absent, then we change it.
You can check a light bulb from a garland using an adjustable power supply, who has it, of course. We connect the light bulb to the terminals, set the voltage to 1.5 volts, the spiral should glow a little. You can add a little voltage, although one and a half volts is enough.
If all the lights and the power cord with an electric plug rang, it is all working properly, but for some reason the garland does not work? We are looking for a wire break in the garland itself.
It's a little simpler here, we set the tester to the diode test mode, put one probe at the beginning of the wire on the board itself, push the second to the wire inside the cartridge where the light bulb stood. We heard a squeak, so the wire is whole, we put the probe on the next wire in the base, and continue the procedure until the end of the New Year's garland.
Garland control unit repair
It happens that the control unit for the flashing of the garlands itself is to blame, a possible malfunction, a simple separation of the wire from the board, as a result of a strong jerk or cold, poor-quality soldering, and other problems.
To eliminate the malfunction, you need to disassemble the plastic box with the control unit itself. On the reverse side there are two screws for a "plus" screwdriver, curly, unscrew them and carefully remove the board.
On the board we see a circuit consisting of electrolytic elements, two transistors, four diodes, one miniature button. On the board is an unpackaged microcircuit that looks like a black drop, and a pair of resistors.
The capacitor in the control unit of the Chinese garland, the electrolyte is installed, which means it has a polarity and must be observed. On the board that I have, it has a nominal value of 10 microfarads, at 25 volts. Transistors PCR 406, if suddenly during the operation of the New Year's garland, one of the transistors exploded, most likely the second will be completely identical. Diodes, all four are marked, IN 4007, a very common diode, there will be no problems with replacement.
As for the unpackaged microcircuit, its denomination is written on the reverse side, B - 803, although in most cases, it is known only to the manufacturer.
Troubleshooting Christmas garland
We are starting to repair the control unit, the Chinese New Year's garland. We solder all the contact points on the board, it happens that cold soldering is not noticeable with the eye, so we perform normal soldering everywhere.
The next step, we check semiconductors, these are diodes and transistors. They are checked by a tester, the diodes should be checked in one direction, and practically do not pass a signal in the opposite direction.
The transistors must be evaporated, for a more accurate check, we check with a tester. We replace damaged parts with new ones or with known serviceable ones, suitable for repair.
Capacitor, resistors and mini button, just check for continuity. When tested, they should not show a short circuit and no resistance.
If you have followed all the recommendations for repairing an electric garland, and it does not work. You can exclude this block from the diagram, and connect the wires in a straight line. You can also completely change all the wires. Of course, this is long and laborious, but for novice radio amateurs, it will be an excellent practice.
