New technologies make life much easier. Thanks to them, solar lamps appeared, which use solar energy to glow at night. Manufacturers offer various types of lamps, which are divided by type and characteristics. Solar powered garden lights are charged by the sun during the daytime and last a long time if the battery is fully charged. Many luminaires have a function to automatically turn on when it gets dark.
Those who follow the style and modern ways of lighting their summer cottages or gardens know that there is a wall lamp for sale that is powered by solar energy. To charge the lamp and prepare it for work in the evening and at night, you just need to place it where the sun's rays fall. If the battery charge conditions are met correctly, the energy is enough for 10 hours of continuous operation of the lamp.
The operation of the LED lamp depends on the level of its charge - it is better to hang the lamp for charging in direct sunlight for the whole day.
Devices charge best when the weather is clear. The service life of such lamps varies and depends on the quality and device. Approximately it is from five to ten years. A significant disadvantage is that in winter, when the sun is inactive, the lamps are not charged.
Types of lamps:
With the use of solar-powered lamps, you can forget about the cost of electricity. There are lamps that work in any weather, and their charge is enough for 12 hours. Lamps with a long-lasting battery are especially popular. The only condition is its regular charge from sunlight or artificial light.
All solar lamps are combined into three groups: design, quality and glass surface. Each solar lamp is different in design and construction. These can be bollards, lamps that are built into steps, devices for lighting ponds, decorative devices and lamps used to illuminate trees.
The photocell used in lamps consists of polycrystalline silicon, which is worse in quality than monocrystalline silicon, which better protects the photocell itself.
The glass surface of the luminaire can be smooth, structured and hardened. Smooth glass reflects a large amount of direct light. Structured glass is characterized by diffuse radiation. Tempered glass is considered the most reliable and high quality.
Advantages of lamps:
It is worth noting that the efficiency of some lamps is significantly reduced on cloudy and rainy days. Lamps are distinguished by their decorative ability: with their help, the site can be decorated beautifully and tastefully. Original solutions can be found on the Internet on sites dedicated to landscape design.
The garden light can be controlled automatically. To do this, you need to study the scheme of the lamp and how it works. A transistor is used in the device of the garden lamp circuit. The type of transistor can be different: it can be domestic or foreign. In order to assemble a simple lamp, you will need ordinary diodes per crystal.
The lamp on conventional diodes can continuously work for seven hours at full heat.
The lamp is charged from the solar panel, which has output parameters: 5.5 v and 200 mA. With these parameters, the lamp can work for more than eight hours. You can make a lamp powered by a solar battery yourself.
Elements of solar lamps:
The solar panel is exposed to ultraviolet light, which allows it to generate an electrical current that charges the battery. Batteries directly feed the LED, which glows at night. When the battery is fully charged, it will typically run for eight hours.
The garden LED lamp on a solar battery is able to work offline, using the charge of solar energy accumulated earlier. You can make a street lamp with your own hands, for this you need to know which elements to use and how to combine them correctly. When making a lamp and choosing elements, it is important to pay attention to the area in which it will be used.
When using lamps that are charged from a solar battery, an abundance of solar activity is important, since without it no charge will occur.
To assemble the lamp circuit, you need to purchase or etch a special printed circuit board. It is better to choose lamps for the lamp with a power of 3W: this will provide normal illumination. As a case, some craftsmen use a deodorant cap.
Item characteristics:
It is important to assemble the circuit right away, otherwise it will take a long time to repair or remake it. Garden lights can be powered by the sun and not batteries. A night light or flashlight will be a wonderful decoration for the garden, while fulfilling its intended purpose.
We bring to your attention an overview of the video on the manufacture of a solar-powered lamp. This light will automatically turn on when it gets dark and turn off when it's light. Also during daylight hours, the battery of the LED is charged by a solar battery.
We will need:
- solar battery 5.5 volts, 90 mAh, size 65x65 mm;
- light;
- at 3.3 Ohm;
- 50 kOhm resistor;
- ;
- off button;
- silicone;
- ;
- plastic box;
- 3.7 volt battery;
- battery box.
An example of a successful do-it-yourself repair of corrosion-damaged solar cells of garden lamps is shown. The Secret of the Master thanks the author of Cosmogor for the provided instructions and a detailed master class on solar battery recovery.
Cheap solar-powered garden lights were purchased, twenty pieces were bought at once, the goods were cheap and working. The whole summer they stood in the garden and at night they were pleasing to the eye. But by the end of the summer, some of the lights stopped working. The next summer, history repeated itself, and by the end of the summer all the lights stopped working. It's a shame!
Analysis of the fixtures revealed the cause of the breakdowns. In view of the leaky fastening of the solar cell, water freely penetrated into the body of the flashlight, and the presence of constant voltage caused electrocorrosion and, unfortunately, a quick death of the electronics. In some flashlights, after disassembly, a very sad picture was observed, on the boards all the tracks disappeared, oxidized and turned into powder, the circuit was actually destroyed, and the legs of the LEDs were corroded to the plastic case, there was nothing to even solder the wires.
Of course, it’s easy to throw out the lamps, but a real master will try to restore with his own hands what can be used in further crafts. The most valuable thing in a garden lamp is a solar battery.
During disassembly, not a single solar battery was working, corrosion did not spare the metal. The photo clearly shows how the metal coating at the positive electrode is eaten away by corrosion. I carefully disassemble the lantern so as not to tear off the metal electrode to which the conductors for removing electricity from the solar cell are soldered. But on some solar cells, this electrode was also destroyed by corrosion, and attempts to solder to the metallization were unsuccessful. And how can you solder the wire to the glass?
solar lantern
Corroded plating
Corroded electrode
So let's start the process of restoring the solar cell, the most valuable part of the lantern.
Step 1. For repairs, you must purchase a conductive adhesive, such as the one in the photo.
Step 2. Unsolder the wires from the electrodes, if there are any left.
Step 3. We clean it from paint, varnish, if there is a film, then we remove it too. The stripping width is a few millimeters and in the place where the wires were soldered.
Step 4. Degrease the surface and apply glue according to the instructions. We restore the electrode eaten by corrosion with glue, applying glue to the cleaned place. Let the glue dry.
Conductive adhesive
We solder the conductors
We clean the damage
Apply conductive adhesive
Step 5. We lean the wire to the place where the glue is applied and drip solder, well, literally a little more. In this state, the wires are still weakly attached to the element; at the slightest jerk, the wire will come off. We fix the wire on the glass with hot glue. In principle, at this step, the restoration of the solar cell with your own hands ends.
When the construction of the country house is completed, construction debris is removed, it's time to think about the improvement of the summer cottage. Places for a gazebo, for flower beds, possibly for a pool have been identified. Paths marked. And then the question arises, how to cover all this economy. You can, of course, use a lamppost and a common street lamp. But at the same time, it is unlikely that in the dark time of the day you will get that unique atmosphere of mystery and comfort that can be created with the help of small various lamps scattered in different places of the site.
Installing such lamps throughout the site is not so difficult. But they need to be powered. But as? Digging trenches and pulling cables to them? Or, worse, hang wires on poles? And install a switch on each lamp? This is irrational. The problem can be solved much easier. Solar-powered lights are being installed on the site. Shops offer a huge selection of such lamps. From the simplest and cheapest, to the most complex and expensive, artistically executed, with program control, with a multi-colored glow.
But the cheapest ones are cheap because their quality leaves much to be desired, and after a year or two of service they can be safely thrown away. And high-quality lamps that would satisfy any exacting taste are expensive and not always affordable. That's when ingenuity comes to the rescue, and craftsmen make solar-powered lanterns themselves, with their own hands. Such a lantern, made with love, conscientiously, will serve faithfully for more than one year. It is absolutely not difficult to make it, as it may seem at first. Some difficulties may arise with the choice of the design of the appearance of the lantern, but this will already depend only on artistic taste. Well, to some extent, from the set of components from which the electric part of the lantern will be assembled.
Before you start buying parts, you need to decide how many fixtures will be installed and in what places. What will be their power. Having decided on this, you can begin to select components for fixtures.
Naturally, for a solar-powered flashlight, you first need to purchase solar modules. On sale there are helium converters of various modifications, quality and efficiency. Considering that the main purpose of these converters is only to charge the battery during daylight hours, then it is quite enough to purchase a certain number of solar modules at retail, from which, if necessary, you can assemble a sufficiently powerful battery.
For these purposes, a solar battery based on polycrystalline silicon 5.5 V, 90 mA, with dimensions of 65x65x3 mm, is quite suitable. This battery is laminated with silicone, thanks to which the battery is completely protected from all kinds of mechanical influences and from moisture. It also kept the weight of the battery down to a minimum of just 15 grams. The battery is ideal for charging batteries 3.6 V - 4.8 V. The retail price of the battery is 137 rubles.
Solar panels Solar Panel 65x65
The next component of the lamp is the battery. A lithium-ion battery with an output voltage of 3.6 V and a capacity of at least 3000 mAh is quite suitable for it.
From commercially available relatively inexpensive batteries, you can choose a set of four lithium-ion batteries model 18650. Each battery has an output voltage of 3.7 V with a capacity of 9800 mAh. The package also includes a charger, which may be quite useful, for example, for the initial charging of batteries. Batteries have the following dimensions: diameter -17 mm, height - 65 mm. The price of the kit (with charger) is 411 rubles.
Model 18650 battery pack with charger
Next, you need to select a luminous element. The most suitable for these purposes is the LED. You can, of course, use LED lamps, but they will consume too much energy. Modern high-brightness LEDs may well satisfy any need, since they can be installed in the right quantity for each specific lamp.
For such flashlights, a five-millimeter super-bright white LED of the 3H5 type (helmet) is quite suitable. Usually it is used in outdoor advertising, in various electronic displays, in road signs. So for a flashlight, it is quite suitable. It can be operated at temperatures from -55°C to +50°C. The cost of one such LED is 10 rubles.
Superbright white LED type 3H5 (helmet)
And, finally, the heart of the lamp is the electronic control unit. In his circuit there are four resistors, costing 1.5 rubles each, two transistors of the KT503 type, costing 9 rubles each, one Schottky diode 11DQ04, costing 24 rubles. It's all on one board.
Separately connected solar battery, battery, LED. You can, of course, collect all this on a piece of foam, textolite, cardboard. But no self-respecting craftsman who collects anything for himself would allow himself such carelessness.
To mount the block, it is not at all necessary to draw and etch the printed circuit board. For these purposes, a universal DIY PCB 42x25mm breadboard is great. This board is designed specifically for mounting and configuring your own electronic circuits. It is made of high quality materials and has gold-plated contacts. The dimensions of such a board are 45x35x2 mm. Weight 2.8 grams. The cost of packaging is 235 rubles. There are 4 boards in a pack.
Universal breadboard DIY PCB 42x25mm
In the manufacture of the electronics unit for installation, it is best to use a wire of the MGTF 0.2 brand. This is a stranded flexible copper wire in fluoroplastic insulation. Works in the temperature range from -60°С to +220°С.
Operating voltages - up to 250 volts AC with a frequency of up to 5 kHz or up to 350 volts DC. A coil of such a wire of 190 meters costs about 15 rubles.
The principle of operation of the electronic unit is extremely simple. The scheme works as follows. While the solar battery is illuminated by the sun, it generates a current that charges the battery through the Schottky diode. At the same time, current flows to the base of transistor T1 and opens it.
Since transistor T1 is open, a zero potential is kept at the base of transistor T2, and this transistor is closed. When darkness falls, the solar panel stops generating electricity, the transistor T1 closes, the base of the transistor T2 through the resistor R2 receives a current that opens it. This creates a power supply circuit for the LED. At the same time, the Schottky diode prevents the battery from discharging to the solar battery.
Schematic diagram of the solar lantern control unit
The capacity and charge of the battery is enough to power several of these LEDs, which will create the desired luminous flux. This scheme allows you to turn on in parallel up to three or four LEDs.
As for the appearance of the lantern, it all depends on the imagination of the master and his taste. Any form can be given that will be most in harmony with the environment. It can be just lanterns for lighting paths, it can be garlands for trees, bushes, it can be decorative lamps for gazebos, for lighting fountains. But all of them will serve long and faithfully. Because they were made by hand.
On the plots, many summer residents have solar-powered garden lamps, mostly made in China, which are not very reliable.
Simple improvements can significantly improve the performance of such lamps.
Garden lights not only decorate the site, but also illuminate the paths, making evening walks in the garden safe. All garden lamps are divided into stationary and autonomous. The placement of stationary lamps on the garden plot is associated with a significant amount of work on laying the electrical cable and installing the lamps themselves. Yes, and their price is very high.
Stationary lamps on the site can be supplemented, or even replaced with stand-alone devices. They will be appropriate literally in every corner of the garden. Especially
Such lamps look spectacular if you place them around the perimeter of the reservoir and along garden paths. There are also autonomous garden spotlights, which are used to illuminate buildings and large ornamental plants.
Despite the variety of models of autonomous garden lamps, they are all assembled according to a typical scheme, which includes a solar battery, a battery, a voltage converter and an LED or LED module. Any of these nodes can be improved, thereby improving the performance of garden lamps - for example, brightness or duration of their operation.
For example, the Tower lamp (Fig. 1) is assembled on a DA1-ANA618 pulse converter (or its analogues - ANA608, Y801, Y8018). The pulse converter increases the voltage of the nickel-cadmium battery to the level necessary to turn on the HL1 LED. In addition, the converter monitors the voltage on the solar battery, and at dusk (when the voltage on the solar battery drops) turns on the lamp. The amount of current flowing through the LED, and, accordingly, the brightness of the LED, depend on the inductance of the inductor L1. In lamps from different manufacturers, a choke with an inductance of 68-82 μH is installed. With this amount of inductance, the current through the LED does not exceed 12 mA, although the operating current for most low power LEDs is 20-30 mA.
To increase the current value (luminaire brightness), you should replace the standard L1 choke with a choke with an inductance of 33 μH. The current flowing through the inductor is very small. Therefore, you can use a choke of almost any design with a given inductance value (photo 1).
The old choke should be removed from the board and onto it. place to install a new one. If the board is welded to the body of the luminaire and deployed by the components inside the lantern, it is not necessary to dismantle it. It is necessary, using a desoldering pump, to remove the solder, and then remove the inductor from the board (photo 2).
Depending on the design, LEDs provide different brightness at a given operating current. For super-bright low-power LEDs, the brightness varies widely from 2 to 20 cd/m2 and higher. The garden lamp under consideration uses a flat-head LED, which, at an operating current of 20 mA, creates a luminous flux with a brightness of about 4 cd / mg. This is enough to illuminate an area within a radius of up to 1.5 meters. Simply replacing this LED with a super bright 5013UWC 20 cd/m2 LED will greatly improve garden light performance.
With an increase in the operating current and brightness of the LED lamp, the current consumed from the battery increases. It is necessary to install a nickel-metal hydride battery with a capacity of 1000 mAh instead of a regular battery with a capacity of 600 mAh, thereby significantly increasing the battery life of the lamp even in cloudy weather (photo 3).
It should be noted that AAA nickel-metal hydride batteries of various capacities are currently being produced: 1,000, 1,100, 1,350, 1,800 and even 2,000 mAh. The larger the capacity of the installed battery, the longer the lamp will work on a single charge.
Before buying a battery, be sure to check the voltage with a multimeter. For a nickel-metal hydride battery, the voltage at the electrodes does not exceed 1.3 V. For salt or alkaline batteries, the voltage at the electrodes is 1.50-1.57 V. Sometimes unscrupulous sellers under the guise of high-capacity nickel-metal hydride batteries sell salt batteries stylized as batteries .
In order for the luminaire to create uniform illumination, instead of one LED, you can install three at an angle of 120 degrees. The LEDs are connected in parallel to each other. Before installation, you should check the spread of their operating voltage, which should be minimal, otherwise only one of the three LEDs will burn brightly, and the rest will only glow dimly. A simple check is easy to implement by assembling a test circuit (Fig. 2). If LEDs from the same batch are used, they will glow with almost the same brightness (photo 4).
It should be borne in mind that the forward voltage drop for LEDs of different glow colors is significantly different (see table).
Therefore, when LEDs of different colors are connected in parallel, the one on which the voltage drop is less will light up.
The LEDs are located on a board with a diameter of 15 mm. The PCB drawing, assembled LED module and solar powered garden light with this LED module are shown in photo 5-6.
You can make garden lamps that will burn in different colors - red, blue, yellow, green, white, purple. It is only necessary to select the appropriate LEDs. Preference should be given to super-bright LEDs, which, with the same operating current, have significantly higher brightness than conventional ones (photo 7).
Regardless of what color LEDs are chosen for the garden lamp, this color will be static, unchanged over time. A much more interesting effect can be achieved using a three-color LED with a built-in generator. Such LEDs are used in more expensive UFO lamps and ball-shaped pond lamps. Compared to ordinary garden lights, the cost of dynamic lights is 15-20 times higher!
Three-color LEDs with a built-in generator contain a microcircuit on one of the electrodes that controls the operation of an RGB matrix mounted on another electrode (photo 8). An LED has two terminals, a cathode and an anode. The anode lead is usually longer. A three-color dynamic LED is connected to the power supply through a current-limiting resistor. The operating current for such an LED is 20 mA. Dynamic LEDs must not be connected to a power source without a current-limiting resistor or apply reverse polarity voltage to them. The maximum reverse voltage of more than 0.5-0.75 V destroys dynamic LEDs.
Three-color dynamic LEDs come in fast fading and slow fading. The latter are most interesting for use in garden lamps. The color of their glow seems to flow from red to yellow, then to green, blue, white, orange and back.
Depending on the number of LEDs purchased and the place of purchase, the cost of LEDs varies markedly. So, a batch of 100 LEDs purchased on the radio market cost the author 10 rubles. apiece, and through the retail network, these same LEDs are sold at 55 rubles.
It is impossible to connect a tri-color LED with a built-in generator to a garden lamp instead of an installed white LED: it simply will not. work. And the reason is simple - the converter installed in: a garden lamp generates a rectangular pulse voltage with a frequency of 200-250 kHz (photo 9). Each new impulse restarts the generator built into the three-color dynamic LED, and for the normal operation of the generator, the impulse voltage must be converted to DC.
The easiest way for these purposes is to use a rectifier diode and a storage capacitor. The diode cuts off negative voltage surges from the converter, and the capacitor discharges in the pauses between pulses to the LED. Thus, from the alternating we get a constant voltage.
When choosing a diode and capacitor, preference should be given to surface mount components. It is highly desirable to install a Schottky diode, which has a minimum voltage drop of 0.12-0.14 V, and the operating frequency reaches hundreds of kilohertz due to the short charge absorption time. It is preferable to use a tantalum capacitor with a low equivalent resistance (photo 10). Under these conditions, the maximum efficiency of the rectifier is ensured.
The diagram of the lamp module is shown in fig. 4, the printed circuit board for the module and the three-color LED - in fig. 5, and the assembled module is in photo 11.
Since it is difficult to convey dynamic events within the framework of a magazine article, a series of photographs in photo 12 is shown to illustrate the operation of a garden lamp with a three-color LED.
Modernizing the garden lamp turned out to be a very simple task. You can decorate your garden with fantastic lighting based on commercially available inexpensive garden lamps, modified by your own hands.
Rice. 1. Principal lamp "Tower". Photo 1. Miniature inductors for surface mounting. Photo 2. Removing the throttle without dismantling the board. Photo 3. AAA batteries. Rice. Fig. 2. Schematic diagram of checking the brightness of the glow. Photo 4. LEDs of the same batch have almost the same brightness of the glow. Photo 5. LED module assembly. Rice. 3. PCB for three LEDs. Photo 6. A lamp with three LEDs. Photo 7. An example of super-bright LEDs. Photo 8. Three-color LED with an RGB control matrix.
Repair and improvement of a solar-powered lamp - photo 2
Photo 9. Oscillogram of the impulse voltage generated by the converter. Photo 10. Tantalum capacitor. Rice. 4. Schematic diagram of the dynamic lamp module. Rice. 5. Printed circuit board of the dynamic lamp module. Photo 11. Dynamic lamp module assembly. Photo 12. Different phases of a dynamic lamp with a three-color LED.
