Christmas tree with a built-in LED garland with your own hands.
Possibly one of the few DIY soldering kits that results in useful product(we do not take into account sets for assembling full-fledged devices), which after assembly will not go to lie in a dark corner, but will be used for its intended purpose, especially if a child is connected to the assembly.
The review contains a description of DIY 3D Christmas trees and assembly instructions.
After assembling the constructor, you should get a 3D tree flashing with 3 colors of LEDs, which can run on 3 AA batteries or be powered by USB.
The set is packed in a bag with a bubble wrap, additionally wrapped in foam. I ordered from this seller () several times, everything arrived without damage in the same package, the equipment was in order. At the time of ordering, he had best price on AliExpress for this Christmas tree, and there were about 200 sales, now there are more than 1700.
As part of the 3D Christmas tree soldering kit:
3 boards (CTR-30C base and 2 tree trunk parts CTR-30A and CTR-30B)
LEDs (12 green, 12 yellow, 13 red)
6 capacitors at 47uF 16V
6 transistors S9014
7 resistors 10KΩ
2 resistors 330 ohm
2 resistors 1KΩ
2 resistors 2KΩ
1 button
1 power connector (length 1 m)
1 USB power cord
2 bolts and 2 nuts
Box for 3*AA batteries
Here's what was included.
Main details close-up. The boards have the EQKIT logo. 
Back side boards: 
Bigger: 
All components were in stock, even an extra LED remained. Before soldering, I checked all the elements with a transistor tester, everything turned out to be in good order. Unfortunately, there are no assembly instructions included.
The seller attached assembly instructions in the form of photographs, but did not sign the resistor values, and the resistor values \u200b\u200bare very hard to see on the attached photos. But the seller is responsive, quickly sent a diagram, though in Chinese, but most importantly from a completely different Christmas tree. After pointing out this fact, he said that he only had such a scheme, but still promised to answer any questions if something could not be assembled. On this, it was decided to finish torturing the seller and try to collect the pictures he has with the assumption that they are still from this set. In the end, everything worked out, below will be indicated all the resistor values and other information on the assembly.
The contact pads on the boards are perfectly tinned. When soldering, I didn’t even have to use flux, what was contained in the solder was enough. He soldered half of the Christmas tree with primitive Chinese, though with separately purchased ones for him. Actually, for the test of new stings, this was started, it turned out that the “unusable” Chinese soldering iron is quite suitable for such simple work, because. native stings did not even want to take solder. I already soldered the other half with a soldering iron at the station with T12 tips. Now I could not determine where and what was soldered, i.e. You can assemble this constructor using any tool, as long as your hands are in the right place :)
I checked the resistors with a multimeter for compliance with the marking and signed for convenience. Perhaps someone will come in handy. 
First, I soldered all the resistors to boards A and B. Everything is clear with 10K resistors, they are signed on the board. The remaining denominations must be placed in the following places:
CTR-30A board
R1, R3, R5, R7 - 10K
R2-2K
R4-1K
R6-330
CTR-30B board
R1, R3, R5 - 10K
R2 - pictured - 330
R4 - pictured - 2K
R6 - pictured - 1K
It turned out the following. You can see where the resistors should be. 
Next, you need to solder the transistors and capacitors. On the board, the capacitors are signed as 22uF, in the kit they go to 47uF, for some reason the Chinese did not save here. We bend the legs of the capacitors and resistors by 90 degrees so that after soldering they lie horizontally on the board, and do not stick out in different directions on the finished product. The negative contact of electrolytic capacitors (C1, C2, C3) is indicated on the board by a shaded area, and on the capacitor itself by a light stripe. The orientation of the transistors (Q1, Q2, Q3) is also indicated on the board in a semicircle, respectively, the contour of the transistor case must match when installed (before bending the legs) with the pattern on the board. In this case, it turned out that all the transistors lie “face down”, and are oriented in the opposite direction from the semicircle on the board.
All resistors, transistors and capacitors are soldered. 
Next, solder the LEDs. The LEDs have polarity, everything is marked on the board. All LEDs are oriented in the same way, so it is enough to remember how to solder one, the rest are similar. For those who are not in the know, in this case, we solder the LED with a short lead (cathode, “-”) closer to the top, respectively, with a long lead (anode, “+”) to the bottom of the tree. During the final assembly of the tree, you will need to solder the last red LED at the top, the polarity is already indicated there, we solder the LED to “+” with a long lead.
Before soldering, we bend the legs of the LEDs at a right angle so that the body of the LED extends beyond the Christmas tree. 
The distribution of LEDs by color is as follows:
Fee A:
D1-D6 - red,
D7-D12 - yellow,
D13-D18 - green.
Board B:
D1-D6 - green,
D7-D12 - red,
D13-D18 - yellow,
All parts on the main boards are soldered. 
Another photo from a different angle. 
I recommend testing the boards before assembly by applying a voltage of 4.5-5V to them. Each board can work independently, i.e., in principle, you can get two 2D Christmas trees. If the Christmas trees work separately, you can proceed to further assembly.
I think it makes no sense to describe the assembly process further, because. everything is obvious. Boards A and B are fixed together with solder. The main thing is not to confuse the polarity when installing the Christmas tree on board C (the polarity is signed everywhere, you need to try to confuse).
The battery holder has a rather long wire, which is not needed here, it is better to cut it to the desired length. Just in case, let me remind you that the red wire must be soldered to the “+” terminal, the black one to the “-” (signed BAT 4.5V).
We solder the power button, the USB power connector, fasten the battery holder - the designer is ready. 
For a more secure fastening of the DC 5V power connector, the kit does not include a metal bracket, although holes for it are provided. Instead, you can use the rest of the legs from the resistor or capacitor, which I did.
Here you can see how the boards are soldered together. Everything is held very confidently, it will fall apart only if you specifically set yourself this goal. 
The Christmas tree works quite well on Ni-MH 1.2V batteries, I tested it on. But when working from USB (5V), the light is still brighter. I tried to measure the power consumption when connected via USB, it shows 0.00A, while the tree blinks with might and main and works as it should, therefore the current consumption is very small, below the minimum threshold of the tester, so the batteries should last for a very long time.
3D tree assembly: 
We turn on the power - the LEDs glow and wink smoothly, pleasing to the eye. 
I liked the toy, it is interesting to collect, and the children too. This is one of those soldering kits that, after assembly, are not thrown into a distant box, but can be used, for example, as a night light for children.
Those who saw this Christmas tree and know what a soldering iron is also wanted to assemble it. Apparently there is something in it ... I bought it in the summer, so I managed to assemble it for the New Year. But now the prices for such sets have decreased.
| amount | Designation and marking of the part on the diagram | |
| 6 | × | 10K resistor R1, R3, R5 on both boards |
| 6 | × | 330 ohm - 3K resistor R2 (2K), R4 (1K), R6 (330) on both boards |
| 1 | × | 2K resistor R7 (on one board only) |
| 6 | × | 47uF capacitor C1, C2, C3 on both boards |
| 6 | × | 9014 transistor Q1, Q2, Q3 on both boards |
| 13 | × | Red LEDs D1-D6 on both boards and D19 (only on one board with R7) |
| 12 | × | Yellow LEDs D7-D12 (on both boards) |
| 12 | × | Green LEDs D13-D18 on both boards |
| 3 | × | Printed circuit boards |
| 4 | × | Battery container with fasteners, power socket, switch and USB power cable |
Set composition
2. Scheme of a 3D Christmas tree and the theory of its work
The numbers of resistors and their rating are indicated on the board, if the rating is not indicated, refer to the table of the set composition. The value of the installed resistor is determined using a color code or by measuring the resistance of the resistor with a device.
Sets of 3D Christmas trees are equipped with pairs of resistors R2, R4, R6 with resistance values different from 1K. In any case, the lowest resistance resistor is installed in the power circuit of the green LEDs D1-D6, and the resistor of the largest resistance in the red LED circuit D7-D12. Putting a low resistance resistor in the power supply circuit of the green LEDs will make them glow a little brighter. Green LEDs are usually less bright than other color LEDs.
Do-it-yourself installation of resistors in the board
Biting off conductors
4. Installing transistors
Installing transistors on the board
Soldering the transistor on the board
Install the transistor from the board marking side. The position of the case must correspond to the drawing on the board. Solder transistors quickly without overheating. Solder all six transistors. Next, solder the electrolytic capacitors.
5. Soldering capacitors
Positive electrode is longer
Negative electrode marking
Polarity marking on the board
The capacitors of the radio designer are soldered
When soldering electrolytic condensates, the polarity of the latter must be taken into account. The negative electrode is marked on the body of the capacitor, and the lead itself is somewhat shorter than the positive lead. The negative electrode on the board is indicated by a shaded stripe. If there is no pattern on the board, then the soldering pad for the positive electrode of the capacitor is usually square. When installing the capacitor on the board, consider its position on the board. Look at the photo. Next, install the LEDs on the board.
6. Soldering the LEDs
Installing the LED in the board
LEDs also have polarity when connected. The long electrode of the LED is positive and the short electrode is negative. Notice again the PCB markings and the square shape of the positive solder pad. When soldering, be sure all LEDs of the same color should be grouped together with a common resistor and transistor, as shown in the diagram. If you solder LEDs of different colors, then one color of the LED will glow brighter than the other color (and the other color may not glow at all!).
Pay attention to the position of the LEDs relative to the board. Diode D19 is not installed yet. After installing the LEDs, it's time to check the correct installation.
7. Checking the operation of soldered boards
After installing all the elements on the 3D Christmas tree board (with the exception of the D19 LED at the tip), the board must be tested. For this, 5 Volt power is supplied to the sites marked "-" and "+" on the tree stump. We insert the batteries into the container and, observing the polarity, touch the conductors to the power contact pads on the board. Watch the video. If all parts are installed and soldered correctly, then all LEDs should flash beautifully. If not, CHECK THE CORRECT INSTALLATION and correct the errors. Next, install the power and switching elements on the base board.
8. Soldering the base board
Correct position of the switch on the board
Installing a 3D Christmas Tree Power Socket
Battery container on the base plate
Soldering battery wires
We solder the 3D tree power switch button and the external power supply socket. Attention! When installing the power switch, the cut side of the button should face the closest edge of the PCB, see photo!. A piece of a cut electrode from a resistor or capacitor is fixed on the board to the power supply socket. Such a loop will firmly fix the sockets on the board. We fix the battery container with screws and nuts on reverse side base fee. See photo. The conductors from the batteries are shortened and soldered observing the polarity to the printed circuit board. Apply power to the board and check the voltage polarity at the pins in the center of the board. Getting Started final assembly Christmas trees.
9. Final assembly
Electronic tree. Board assembly key
Connecting boards together
We collect two boards in a herringbone, the arrows on the boards should be nearby. Fix the position of the boards relative to each other by soldering one pad on the tree trunk.
Connecting three boards together
We insert the Christmas tree into the base printed circuit board, observing the polarity indications (“+” and “-”) on all three printed circuit boards. Make sure the tree is installed correctly and solder the contacts and remaining pads on the tree trunk.
3D led tree Can be powered by battery pack or USB power supply. When the USB power plug is inserted, the batteries are disabled by the socket's internal contact, so the batteries can be left on when powered by USB.
Be careful when supplying USB power from gadgets and laptops, not all of them will be able to power the Christmas tree. Radioconstructor a set of parts for assembling a 3D Christmas tree you can purchase at the following link http://ali.pub/2rdf6t . How the tree glows, look at the video
Successful assembly of a 3D Christmas tree with your own hands.
As an add-on, only one Christmas tree can be installed on the base board. And connect the second board to the batteries or via a USB cable, for example, to a power bank. The board can be fixed on a headdress or on outerwear. The night will look very cool. Then from the set you get two Christmas trees.
On the eve of the New Year, I want to do something festive! And most the best decoration At home, this is everyone's favorite Christmas tree.
For achievement home comfort we need: a small piece of wallpaper (or some kind of cardboard), green rain, adhesive tape and even hands.
We wind our sheet of paper in the shape of a cone and fix it with tape. Next, fold it and trim the bottom evenly so that it can stand straight. Then we take some copper wire (0.3..0.5mm) and wrap our cone, fixing the wire with tape, this will give it elasticity. We cut it in height (it is more convenient to install rows of LEDs). After the tiered (they are numbered in the diagram) installation of the LEDs, we fasten the section with tape familiar to us. We also place the board inside the Christmas tree. At the next stage, starting from the top, we wrap the cone with green rain so that the LEDs protrude a little. Well, by design...
As for the schema. We supply 7..12V (I think everyone has enough such blocks) to the stabilizer, to power the controller and make a common + (not stabilized) which is common to all LEDs. From this common wire, LEDs are switched on in parallel in each tier, we do this so that we do not have to pull two wires to each group of LEDs. At the outputs of the MK, 0 or 1 appear in turn, which go to the bases of the transistors to open them. Transistors are needed, since several LEDs are connected to each port of the MK, the controller may not draw all these currents. By the way, current-limiting resistors can be placed between the ports of the MK and the bases of the transistors. The LEDs are connected with a "minus" to the collectors (emitters to ground), and in front of their "plus" there are current-setting resistors. I think there should be no questions about the operation of the scheme ...
Transistors: BC547 (or any equivalent)
Current-setting resistors: 200 Ohm...1kOhm
Capacitors: any (these are power filters) from 0.1uF
In the diagram, the numbering (1-6) is our tiers of LEDs, starting from the bottom. The 6th is our top, an asterisk or something like that. Do not confuse, otherwise the glow pattern will disappear!
The application has a source code in, whoever wants can rewrite the program at their discretion.
List of radio elements
| Designation | Type | Denomination | Quantity | Note | Score | My notepad |
|---|---|---|---|---|---|---|
| MK AVR 8-bit | ATmega8 | 1 | To notepad | |||
| Linear Regulator | L78L05 | 1 | To notepad | |||
| bipolar transistor | BC547 | 12 | To notepad | |||
| Resistor | 10 kOhm | 1 | To notepad | |||
| Resistor | ~900 Ohm | 38 | To notepad | |||
| Capacitor | 0.1uF | 2 |
Hello!!! Happy New Year, everyone!! Let all the bad things stay in the old year, and all the good things will be with us in the new year!! So in this article I want to tell you how to make in just a couple of hours just such a small Christmas tree that can decorate yours, for example workplace, in the new year, or can stand somewhere at home
The basis of the device is a simple multivibrator.
The oscillation frequency depends on the ratings of the capacitances and resistors in the base circuits. Wide field for experiments.
What do we need?
1) LEDs. I used three colors green 6pcs, yellow 6pcs and red 7pcs.
2) Resistors. 10kOhm - 2pcs, and 1kOhm - equal to the number of LEDs used.
3) Pair of transistors
4) Heat shrink with a diameter of 2 and 4 mm
5) Copper wire, varnished, approx. 0.8 or 0.7 mm thick
6) Something else...
The wire must be cut into pieces about 10-15 cm long. The number of such segments should be equal to the number of LEDs multiplied by two. It is advisable to make half of the segments 10 cm, the second half 15 cm.
Resistors are soldered to the LEDs, then all this is soldered to our wire segments, as in the figure.
Then the resistors on the LEDs are "hidden" in heat shrink.
After that, it is necessary to once again check each LED with a resistor for operability, and clarify the polarity. Then we twist together all the "pluses" of the LEDs, and all the "minuses" Then, as it were, we split the bunch of "pluses" into two so that we get two approximately identical groups of LEDs that we will connect to our multivibrator. Approximately like this.
I made a multivibrator hinged mounting on two KT816G transistors, and unfortunately I did not have time to take a picture.
It remains to shove all this into any suitable case, and voila !! Enjoy!!
Somehow, before the New Year, I was left without a Christmas tree and without Christmas decorations (since it was in the middle of the ocean). And the soul demanded a holiday ... I still somehow imitated the Christmas tree, but I had to think about the toys. It was then that the remnants of multi-colored LED strips came to hand.
Next, I’ll chew it out first, and then I’ll briefly describe how to make original LED Christmas tree decorations. And at the same time we will consider connection options.
For this we take led strip different colors, not in silicone.
The first one will be round, we will chew it
| White ribbons look festive, in the sense of being painted white. | |
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Cut the tape with scissors right places into correct segments of three LEDs |
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For this decoration, we need three segments |
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Glue them together with a sticky base |
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We fasten the first two segments in the form of the letter "L". Please note that you need to observe the polarity and place the tape segments with poles to each other, i.e. so that the plus of one tape is directed to the plus of the other. |
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We glue the third across, getting something like the letter "A" |
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We tin the sites at the ends of the tapes, so that later it would be easier to solder |
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And we connect them in pairs with each other with wires, here I connected two "pluses" |
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After soldering all the wires, we get such a Christmas tree toy. Here I have short wiring without insulation - this is wrong, everything must be isolated. By the way, short ones are a plus, and long ones are a minus. |
Further, it would be correct to describe how and to what this joy is connected, but this will be later, but now I want to consider what other options there are.
Other variants with a large number of segments
Square
Further along the increasing number of segments is a square of four segments. I won’t chew it anymore, I think from the photo you can understand the principle. I just wanted to pay attention to the top two wires, they are both needed for a complete circuit. It is not visible in the photo, but I made the upper wire in the form of a loop.
Star
The star, of course, already consists of five segments. Here, the peculiarity is that there are practically no wires, and the tape segments are attached to each other by soldering two contact pads to each other (do not forget to observe the polarity!).
six pointed star
Consists of six sections. Rather, these are two intertwined triangles, and I made them from different ribbons (different colors).
Ball
I also tried to make something in volume and got such a ball. But I didn't really like it and I stopped there.
More cuts
You can go further by building up sections of tape, but, IMHO, this is already too much, then just glue on some kind of base and make applications of snowflakes.In work
This is what it looks like when lit:
Connection
Option 1: simple in 12v
The easiest way is to stupidly turn everything into 12 volts and there will be multi-colored toys shining steadily. We just solder the connector that hangs on each reel with 5 meter tapes and stick a regular 12 volt power supply there, which is sold in the same place as the tapes.
The toys are soldered one after the other. 
Option 2: RGB Controller
More interesting option, is to connect to the RGB controller, which are on this moment more than affordable, with a large selection of both functions and capacities.If you connect the toys of the same color in rows to the corresponding controller output (a row of red ones to the R pin, green to G, blue to B), we get a Christmas tree in the MoodLamp style - with a customizable color as desired.
Please note that on such controllers, control is carried out on the "ground" (as a rule), i.e. common to all channels is the "plus" wire.
Option 3: Microcontroller
This is the most fun option, although the most complex and time-consuming. Those. it is optimal to take some Arduino and a shield with a TLC5940, connect LED toys to 16 channels, connect a sound sensor and get a disco tree.This is what I did last year:
Here is a small past-New Year's video report:
Threat. Who needs a sketch from this video