How New Year's garlands are arranged. How much power does an LED consume? DIY LED voltage indicator design
The times when LEDs were used only as indicators for turning on devices are long gone. Modern LED devices can completely replace incandescent lamps in household, industrial and. This is facilitated by the various characteristics of LEDs, knowing which you can choose the right LED analogue. The use of LEDs, given their basic parameters, opens up a wealth of possibilities in the field of lighting.
A light-emitting diode (denoted as LED, LED, LED in English) is a device based on an artificial semiconductor crystal. When an electric current is passed through it, the phenomenon of emission of photons is created, which leads to a glow. This glow has a very narrow spectral range, and its color depends on the semiconductor material.
LEDs with red and yellow emission are made from inorganic semiconductor materials based on gallium arsenide, green and blue ones are made on the basis of indium gallium nitride. To increase the brightness of the luminous flux, various additives are used or the multilayer method is used, when a layer of pure aluminum nitride is placed between semiconductors. As a result of the formation of several electron-hole (p-n) transitions in one crystal, the brightness of its glow increases.
There are two types of LEDs: for indication and lighting. The former are used to indicate the inclusion of various devices in the network, and also as sources of decorative lighting. They are colored diodes placed in a translucent case, each of them has four terminals. Devices emitting infrared light are used in devices for remote control of devices (remote control).
In the lighting area, LEDs are used that emit white light. LEDs are classified by color into cool white, neutral white and warm white. There is a classification of LEDs used for lighting according to the installation method. The SMD LED designation means that the device consists of an aluminum or copper substrate on which the diode crystal is placed. The substrate itself is located in a housing, the contacts of which are connected to the contacts of the LED.
Another type of LED is designated OCB. In such a device, many crystals coated with phosphor are placed on one board. Thanks to this design, a high brightness of the glow is achieved. This technology is used in production with a large luminous flux in a relatively small area. In turn, this makes the production of LED lamps the most accessible and inexpensive.
Note! Comparing lamps based on SMD and COB LEDs, it can be noted that the former can be repaired by replacing a failed LED. If a COB LED lamp does not work, you will have to change the entire board with diodes.
LED characteristics
When choosing a suitable LED lamp for lighting, you should take into account the parameters of the LEDs. These include supply voltage, power, operating current, efficiency (luminous output), glow temperature (color), radiation angle, dimensions, degradation period. Knowing the basic parameters, it will be possible to easily select devices to obtain a particular illumination result.
LED current consumption
As a rule, a current of 0.02A is provided for conventional LEDs. However, there are LEDs rated at 0.08A. These LEDs include more powerful devices, the design of which involves four crystals. They are located in one building. Since each of the crystals consumes 0.02A, in total one device will consume 0.08A.
The stability of LED devices depends on the current value. Even a slight increase in current helps to reduce the radiation intensity (aging) of the crystal and increase the color temperature. This ultimately leads to the LEDs turning blue and failing prematurely. And if the current increases significantly, the LED immediately burns out.
To limit the current consumption, the designs of LED lamps and luminaires include current stabilizers for LEDs (drivers). They convert the current, bringing it to the value required by the LEDs. In the case when you need to connect a separate LED to the network, you need to use current-limiting resistors. The resistor resistance for an LED is calculated taking into account its specific characteristics.
Helpful advice! To choose the right resistor, you can use the LED resistor calculator available on the Internet.
LED voltage
How to find out the LED voltage? The fact is that LEDs do not have a supply voltage parameter as such. Instead, the voltage drop characteristic of the LED is used, which means the amount of voltage the LED outputs when the rated current passes through it. The voltage value indicated on the packaging reflects the voltage drop. Knowing this value, you can determine the voltage remaining on the crystal. It is this value that is taken into account in the calculations.
Given the use of various semiconductors for LEDs, the voltage for each of them may be different. How to find out how many volts an LED is? You can determine it by the color of the devices. For example, for blue, green and white crystals the voltage is about 3V, for yellow and red crystals it is from 1.8 to 2.4V.
When using a parallel connection of LEDs of identical ratings with a voltage value of 2V, you may encounter the following: as a result of variations in parameters, some emitting diodes will fail (burn out), while others will glow very faintly. This will happen due to the fact that when the voltage increases even by 0.1V, the current passing through the LED increases by 1.5 times. Therefore, it is so important to ensure that the current matches the LED rating.
Light output, beam angle and LED power
The luminous flux of diodes is compared with other light sources, taking into account the strength of the radiation they emit. Devices measuring about 5 mm in diameter produce from 1 to 5 lumens of light. While the luminous flux of a 100W incandescent lamp is 1000 lm. But when comparing, it is necessary to take into account that a regular lamp has diffused light, while an LED has directional light. Therefore, the dispersion angle of the LEDs must be taken into account.
The scattering angle of different LEDs can range from 20 to 120 degrees. When illuminated, LEDs produce brighter light in the center and reduce illumination towards the edges of the dispersion angle. Thus, LEDs illuminate a specific space better while using less power. However, if it is necessary to increase the illumination area, diverging lenses are used in the design of the lamp.
How to determine the power of LEDs? To determine the power of an LED lamp required to replace an incandescent lamp, it is necessary to apply a coefficient of 8. Thus, you can replace a conventional 100W lamp with an LED device with a power of at least 12.5W (100W/8). For convenience, you can use the data from the table of correspondence between the power of incandescent lamps and LED light sources:
| Incandescent lamp power, W | Corresponding power of LED lamp, W |
| 100 | 12-12,5 |
| 75 | 10 |
| 60 | 7,5-8 |
| 40 | 5 |
| 25 | 3 |
When using LEDs for lighting, the efficiency indicator is very important, which is determined by the ratio of luminous flux (lm) to power (W). Comparing these parameters for different light sources, we find that the efficiency of an incandescent lamp is 10-12 lm/W, a fluorescent lamp is 35-40 lm/W, and an LED lamp is 130-140 lm/W.
Color temperature of LED sources
One of the important parameters of LED sources is the glow temperature. The units of measurement for this quantity are degrees Kelvin (K). It should be noted that all light sources are divided into three classes according to their glow temperature, among which warm white has a color temperature of less than 3300 K, daylight white - from 3300 to 5300 K, and cool white over 5300 K.
Note! The comfortable perception of LED radiation by the human eye directly depends on the color temperature of the LED source.
The color temperature is usually indicated on the labeling of LED lamps. It is designated by a four-digit number and the letter K. The choice of LED lamps with a certain color temperature directly depends on the characteristics of its use for lighting. The table below displays options for using LED sources with different glow temperatures:
| LED color | Color temperature, K | Lighting Use Cases | |
| White | Warm | 2700-3500 | Lighting for domestic and office premises as the most suitable analogue of an incandescent lamp |
| Neutral (daytime) | 3500-5300 | The excellent color rendition of such lamps allows them to be used for lighting workplaces in production. | |
| Cold | over 5300 | Mainly used for street lighting, and also used in hand-held lanterns | |
| Red | 1800 | As a source of decorative and phyto-lighting | |
| Green | - | ||
| Yellow | 3300 | Lighting design of interiors | |
| Blue | 7500 | Illumination of surfaces in the interior, phyto-lighting | |
The wave nature of color allows the color temperature of LEDs to be expressed using wavelength. The marking of some LED devices reflects the color temperature precisely in the form of an interval of different wavelengths. The wavelength is designated λ and is measured in nanometers (nm).
Standard sizes of SMD LEDs and their characteristics
Considering the size of SMD LEDs, devices are classified into groups with different characteristics. The most popular LEDs with standard sizes are 3528, 5050, 5730, 2835, 3014 and 5630. The characteristics of SMD LEDs vary depending on the size. Thus, different types of SMD LEDs differ in brightness, color temperature, and power. In LED markings, the first two digits indicate the length and width of the device.
Basic parameters of SMD 2835 LEDs
The main characteristics of SMD LEDs 2835 include an increased radiation area. Compared to the SMD 3528 device, which has a round working surface, the SMD 2835 radiation area has a rectangular shape, which contributes to greater light output with a smaller element height (about 0.8 mm). The luminous flux of such a device is 50 lm.
The SMD 2835 LED housing is made of heat-resistant polymer and can withstand temperatures up to 240°C. It should be noted that the radiation degradation in these elements is less than 5% over 3000 hours of operation. In addition, the device has a fairly low thermal resistance of the crystal-substrate junction (4 C/W). The maximum operating current is 0.18A, the crystal temperature is 130°C.
Based on the color of the glow, there are warm white with a glow temperature of 4000 K, daytime white - 4800 K, pure white - from 5000 to 5800 K and cool white with a color temperature of 6500-7500 K. It is worth noting that the maximum luminous flux is for devices with cool white glow, the minimum is for warm white LEDs. The design of the device has enlarged contact pads, which promotes better heat dissipation.
Helpful advice! SMD 2835 LEDs can be used for any type of installation.
Characteristics of SMD 5050 LEDs
The SMD 5050 housing design contains three LEDs of the same type. LED sources of blue, red and green colors have technical characteristics similar to SMD 3528 crystals. The operating current of each of the three LEDs is 0.02A, therefore the total current of the entire device is 0.06A. To ensure that the LEDs do not fail, it is recommended not to exceed this value.
LED devices SMD 5050 have a forward voltage of 3-3.3V and a light output (mains flux) of 18-21 lm. The power of one LED is the sum of three power values of each crystal (0.7 W) and amounts to 0.21 W. The color of the glow emitted by the devices can be white in all shades, green, blue, yellow and multi-colored.
The close arrangement of LEDs of different colors in one SMD 5050 package made it possible to implement multi-color LEDs with separate control of each color. To regulate luminaires using SMD 5050 LEDs, controllers are used, so that the color of the glow can be smoothly changed from one to another after a given amount of time. Typically, such devices have several control modes and can adjust the brightness of the LEDs.
Typical characteristics of SMD 5730 LED
SMD 5730 LEDs are modern representatives of LED devices, the housing of which has geometric dimensions of 5.7x3 mm. They belong to ultra-bright LEDs, the characteristics of which are stable and qualitatively different from the parameters of their predecessors. Manufactured using new materials, these LEDs are characterized by increased power and highly efficient luminous flux. In addition, they can work in conditions of high humidity, are resistant to temperature changes and vibration, and have a long service life.
There are two types of devices: SMD 5730-0.5 with a power of 0.5 W and SMD 5730-1 with a power of 1 W. A distinctive feature of the devices is the ability to operate on pulsed current. The rated current of SMD 5730-0.5 is 0.15A; during pulse operation, the device can withstand current up to 0.18A. This type of LEDs provides a luminous flux of up to 45 lm.
SMD 5730-1 LEDs operate at a constant current of 0.35A, in pulsed mode - up to 0.8A. The light output efficiency of such a device can be up to 110 lm. Thanks to the heat-resistant polymer, the device body can withstand temperatures up to 250°C. The dispersion angle of both types of SMD 5730 is 120 degrees. The degree of luminous flux degradation is less than 1% when operating for 3000 hours.
Cree LED Specifications
The Cree company (USA) is engaged in the development and production of ultra-bright and most powerful LEDs. One of the Cree LED groups is represented by the Xlamp series of devices, which are divided into single-chip and multi-chip. One of the features of single-crystal sources is the distribution of radiation along the edges of the device. This innovation made it possible to produce lamps with a large luminous angle using a minimum number of crystals.
In the XQ-E High Intensity series of LED sources, the beam angle ranges from 100 to 145 degrees. Having small geometric dimensions of 1.6x1.6 mm, the power of ultra-bright LEDs is 3 Volts, and the luminous flux is 330 lm. This is one of the newest developments from Cree. All LEDs, the design of which is developed on the basis of a single crystal, have high-quality color rendering within CRE 70-90.
Related article:
How to make or repair an LED garland yourself. Prices and main characteristics of the most popular models.
Cree has released several versions of multi-chip LED devices with the latest power types from 6 to 72 Volts. Multichip LEDs are divided into three groups, which include devices with high voltage, power up to 4W and above 4W. Sources up to 4W contain 6 crystals in MX and ML type housings. The dispersion angle is 120 degrees. You can buy Cree LEDs of this type with white warm and cool colors.
Helpful advice! Despite the high reliability and quality of light, you can buy powerful LEDs of the MX and ML series at a relatively low price.
The group over 4W includes LEDs made from several crystals. The largest in the group are the 25W devices represented by the MT-G series. The company's new product is XHP model LEDs. One of the large LED devices has a 7x7 mm body, its power is 12W, and the light output is 1710 lm. High voltage LEDs combine small dimensions and high light output.
LED connection diagrams
There are certain rules for connecting LEDs. Taking into account that the current passing through the device moves only in one direction, for long-term and stable operation of LED devices it is important to take into account not only a certain voltage, but also the optimal current value.
Connection diagram for LED to 220V network
Depending on the power source used, there are two types of circuits for connecting LEDs to 220V. In one of the cases it is used with limited current, in the second - a special one that stabilizes the voltage. The first option takes into account the use of a special source with a certain current strength. A resistor is not required in this circuit, and the number of connected LEDs is limited by the driver power.
To designate LEDs in the diagram, two types of pictograms are used. Above each schematic image there are two small parallel arrows pointing upward. They symbolize the bright glow of the LED device. Before connecting the LED to 220V using a power supply, you must include a resistor in the circuit. If this condition is not met, this will lead to the fact that the working life of the LED will be significantly reduced or it will simply fail.
If you use a power supply when connecting, then only the voltage in the circuit will be stable. Considering the insignificant internal resistance of an LED device, turning it on without a current limiter will lead to the device burning out. That is why a corresponding resistor is introduced into the LED switching circuit. It should be noted that resistors come in different values, so they must be calculated correctly.
Helpful advice! The negative aspect of circuits for connecting an LED to a 220 Volt network using a resistor is the dissipation of high power when it is necessary to connect a load with increased current consumption. In this case, the resistor is replaced with a quenching capacitor.
How to calculate the resistance for an LED
When calculating the resistance for an LED, they are guided by the formula:
U = IxR,
where U is voltage, I is current, R is resistance (Ohm’s law). Let's say you need to connect an LED with the following parameters: 3V - voltage and 0.02A - current. So that when connecting an LED to 5 Volts on the power supply it does not fail, you need to remove the extra 2V (5-3 = 2V). To do this, you need to include a resistor with a certain resistance in the circuit, which is calculated using Ohm’s law:
R = U/I.
Thus, the ratio of 2V to 0.02A will be 100 Ohms, i.e. This is exactly the resistor needed.
It often happens that, given the parameters of the LEDs, the resistance of the resistor has a value that is non-standard for the device. Such current limiters cannot be found at points of sale, for example, 128 or 112.8 ohms. Then you should use resistors whose resistance is the closest value compared to the calculated value. In this case, the LEDs will not function at full capacity, but only at 90-97%, but this will be invisible to the eye and will have a positive effect on the life of the device.
There are many options for LED calculation calculators on the Internet. They take into account the main parameters: voltage drop, rated current, output voltage, number of devices in the circuit. By specifying the parameters of LED devices and current sources in the form field, you can find out the corresponding characteristics of resistors. To determine the resistance of color-coded current limiters, there are also online calculations of resistors for LEDs.
Schemes for parallel and serial connection of LEDs
When assembling structures from several LED devices, circuits for connecting LEDs to a 220 Volt network with a serial or parallel connection are used. At the same time, for correct connection, it should be taken into account that when LEDs are connected in series, the required voltage is the sum of the voltage drops of each device. While when LEDs are connected in parallel, the current strength is added up.
If the circuits use LED devices with different parameters, then for stable operation it is necessary to calculate the resistor for each LED separately. It should be noted that no two LEDs are exactly alike. Even devices of the same model have minor differences in parameters. This leads to the fact that when a large number of them are connected in a series or parallel circuit with one resistor, they can quickly degrade and fail.
Note! When using one resistor in a parallel or series circuit, you can only connect LED devices with identical characteristics.
The discrepancy in parameters when connecting several LEDs in parallel, say 4-5 pieces, will not affect the operation of the devices. But if you connect a lot of LEDs to such a circuit, it will be a bad decision. Even if LED sources have a slight variation in characteristics, this will cause some devices to emit bright light and burn out quickly, while others will glow dimly. Therefore, when connecting in parallel, you should always use a separate resistor for each device.
As for the series connection, there is economical consumption here, since the entire circuit consumes an amount of current equal to the consumption of one LED. In a parallel circuit, the consumption is the sum of the consumption of all LED sources included in the circuit.
How to connect LEDs to 12 Volts
In the design of some devices, resistors are provided at the manufacturing stage, which makes it possible to connect LEDs to 12 Volts or 5 Volts. However, such devices cannot always be found on sale. Therefore, in the circuit for connecting LEDs to 12 volts, a current limiter is provided. The first step is to find out the characteristics of the connected LEDs.
Such a parameter as the forward voltage drop for typical LED devices is about 2V. The rated current of these LEDs corresponds to 0.02A. If you need to connect such an LED to 12V, then the “extra” 10V (12 minus 2) must be extinguished with a limiting resistor. Using Ohm's law you can calculate the resistance for it. We get that 10/0.02 = 500 (Ohm). Thus, a resistor with a nominal value of 510 Ohms is required, which is the closest in the range of E24 electronic components.
In order for such a circuit to work stably, it is also necessary to calculate the power of the limiter. Using the formula based on which power is equal to the product of voltage and current, we calculate its value. We multiply a voltage of 10V by a current of 0.02A and get 0.2W. Thus, a resistor is required, the standard power rating of which is 0.25W.
If it is necessary to include two LED devices in the circuit, then it should be taken into account that the voltage dropped across them will already be 4V. Accordingly, the resistor will have to extinguish not 10V, but 8V. Consequently, further calculation of the resistance and power of the resistor is done based on this value. The location of the resistor in the circuit can be provided anywhere: on the anode side, cathode side, between the LEDs.
How to test an LED with a multimeter
One way to check the operating condition of LEDs is to test with a multimeter. This device can diagnose LEDs of any design. Before checking the LED with a tester, the device switch is set in the “testing” mode, and the probes are applied to the terminals. When the red probe is connected to the anode and the black probe to the cathode, the crystal should emit light. If the polarity is reversed, the device display should display “1”.
Helpful advice! Before testing the LED for functionality, it is recommended to dim the main lighting, since during testing the current is very low and the LED will emit light so weakly that in normal lighting it may not be noticeable.
Testing LED devices can be done without using probes. To do this, insert the anode into the holes located in the lower corner of the device into the hole with the symbol “E”, and the cathode into the hole with the indicator “C”. If the LED is in working condition, it should light up. This testing method is suitable for LEDs with sufficiently long contacts that have been cleared of solder. The position of the switch does not matter with this method of checking.
How to check LEDs with a multimeter without desoldering? To do this, you need to solder pieces of a regular paper clip to the tester probes. A textolite gasket, which is placed between the wires and then treated with electrical tape, is suitable as insulation. The output is a kind of adapter for connecting probes. The clips spring well and are securely fixed in the connectors. In this form, you can connect the probes to the LEDs without removing them from the circuit.
What can you make from LEDs with your own hands?
Many radio amateurs practice assembling various designs from LEDs with their own hands. Self-assembled products are not inferior in quality, and sometimes even surpass their manufactured counterparts. These can be color and music devices, flashing LED designs, do-it-yourself LED running lights and much more.
DIY current stabilizer assembly for LEDs
To prevent the LED's life from being exhausted ahead of schedule, it is necessary that the current flowing through it has a stable value. It is known that red, yellow and green LEDs can cope with increased current load. While blue-green and white LED sources, even with a slight overload, burn out in 2 hours. Thus, for the LED to operate normally, it is necessary to resolve the issue with its power supply.
If you assemble a chain of series- or parallel-connected LEDs, you can provide them with identical radiation if the current passing through them has the same strength. In addition, reverse current pulses can negatively affect the life of LED sources. To prevent this from happening, it is necessary to include a current stabilizer for the LEDs in the circuit.
The qualitative characteristics of LED lamps depend on the driver used - a device that converts voltage into a stabilized current with a specific value. Many radio amateurs assemble a 220V LED power supply circuit with their own hands based on the LM317 microcircuit. The elements for such an electronic circuit are low cost and such a stabilizer is easy to construct.
When using a current stabilizer on LM317 for LEDs, the current is adjusted within 1A. A rectifier based on LM317L stabilizes the current to 0.1A. The device circuit uses only one resistor. It is calculated using an online LED resistance calculator. Available devices are suitable for power supply: power supplies from a printer, laptop or other consumer electronics. It is not profitable to assemble more complex circuits yourself, since they are easier to purchase ready-made.
DIY LED DRLs
The use of daytime running lights (DRL) on cars significantly increases the visibility of the car during daylight hours by other road users. Many car enthusiasts practice self-assembly of DRLs using LEDs. One of the options is a DRL device of 5-7 LEDs with a power of 1W and 3W for each block. If you use less powerful LED sources, the luminous flux will not meet the standards for such lights.
Helpful advice! When making DRLs with your own hands, take into account the requirements of GOST: luminous flux 400-800 cd, luminous angle in the horizontal plane - 55 degrees, in the vertical plane - 25 degrees, area - 40 cm².
For the base, you can use a board made of aluminum profile with pads for mounting LEDs. The LEDs are fixed to the board using a thermally conductive adhesive. Optics are selected according to the type of LED sources. In this case, lenses with a luminous angle of 35 degrees are suitable. Lenses are installed on each LED separately. The wires are routed in any convenient direction.
Next, a housing is made for the DRLs, which also serves as a radiator. For this you can use a U-shaped profile. The finished LED module is placed inside the profile, secured with screws. All free space can be filled with transparent silicone-based sealant, leaving only the lenses on the surface. This coating will serve as a moisture barrier.
Connecting the DRL to the power supply requires the mandatory use of a resistor, the resistance of which is pre-calculated and tested. Connection methods may vary depending on the car model. Connection diagrams can be found on the Internet.
How to make LEDs blink
The most popular flashing LEDs, which can be purchased ready-made, are devices that are controlled by the potential level. The blinking of the crystal occurs due to a change in power supply at the terminals of the device. Thus, a two-color red-green LED device emits light depending on the direction of the current passing through it. The blinking effect in the RGB LED is achieved by connecting three separate control pins to a specific control system.
But you can make an ordinary single-color LED blink, having a minimum of electronic components in your arsenal. Before you make a flashing LED, you need to choose a working circuit that is simple and reliable. You can use a flashing LED circuit, which will be powered from a 12V source.
The circuit consists of a low-power transistor Q1 (silicon high-frequency KTZ 315 or its analogues are suitable), a resistor R1 820-1000 Ohms, a 16-volt capacitor C1 with a capacity of 470 μF and an LED source. When the circuit is turned on, the capacitor is charged to 9-10V, after which the transistor opens for a moment and transfers the accumulated energy to the LED, which begins to blink. This circuit can only be implemented when powered from a 12V source.
You can assemble a more advanced circuit that works in a similar way to a transistor multivibrator. The circuit includes transistors KTZ 102 (2 pcs.), resistors R1 and R4 of 300 Ohms each to limit the current, resistors R2 and R3 of 27000 Ohms each to set the base current of the transistors, 16-volt polar capacitors (2 pcs. with a capacity of 10 uF) and two LED sources. This circuit is powered by a 5V DC voltage source.
The circuit operates on the “Darlington pair” principle: capacitors C1 and C2 are alternately charged and discharged, which causes a particular transistor to open. When one transistor supplies energy to C1, one LED lights up. Next, C2 is smoothly charged, and the base current of VT1 is reduced, which leads to the closing of VT1 and the opening of VT2 and another LED lights up.
Helpful advice! If you use a supply voltage above 5V, you will need to use resistors with a different value to prevent failure of the LEDs.
DIY LED color music assembly
To implement fairly complex color music circuits on LEDs with your own hands, you must first understand how the simplest color music circuit works. It consists of one transistor, a resistor and an LED device. Such a circuit can be powered from a source rated from 6 to 12V. The operation of the circuit occurs due to cascade amplification with a common radiator (emitter).
The VT1 base receives a signal with varying amplitude and frequency. When signal fluctuations exceed a specified threshold, the transistor opens and the LED lights up. The disadvantage of this scheme is the dependence of blinking on the degree of the sound signal. Thus, the effect of color music will appear only at a certain level of sound volume. If you increase the sound. The LED will be on all the time, and when it decreases, it will flash slightly.
To achieve a full effect, they use a color music circuit using LEDs, dividing the sound range into three parts. The circuit with a three-channel audio converter is powered from a 9V source. A huge number of color music schemes can be found on the Internet at various amateur radio forums. These can be color music schemes using a single-color strip, an RGB LED strip, as well as a scheme for smoothly switching LEDs on and off. You can also find diagrams of running LED lights online.
DIY LED voltage indicator design
The voltage indicator circuit includes resistor R1 (variable resistance 10 kOhm), resistors R1, R2 (1 kOhm), two transistors VT1 KT315B, VT2 KT361B, three LEDs - HL1, HL2 (red), HLЗ (green). X1, X2 – 6-volt power supplies. In this circuit, it is recommended to use LED devices with a voltage of 1.5V.
The operating algorithm of a homemade LED voltage indicator is as follows: when voltage is applied, the central green LED source lights up. In the event of a voltage drop, the red LED located on the left turns on. An increase in voltage causes the red LED on the right to light up. With the resistor in the middle position, all transistors will be in the closed position, and voltage will only flow to the central green LED.
Transistor VT1 opens when the resistor slider is moved up, thereby increasing the voltage. In this case, the voltage supply to HL3 stops, and it is supplied to HL1. When the slider moves down (voltage decreases), transistor VT1 closes and VT2 opens, which will provide power to the LED HL2. With a slight delay, LED HL1 will go out, HL3 will flash once and HL2 will light up.
Such a circuit can be assembled using radio components from outdated equipment. Some assemble it on a textolite board, observing a 1:1 scale with the dimensions of the parts so that all elements can fit on the board.
The limitless potential of LED lighting makes it possible to independently design various lighting devices from LEDs with excellent characteristics and a fairly low cost.
Dmitry Kandinsky
We continue to introduce you to new trends in the field of alternative energy sources together with the Tomsk Center for Resource Saving and Energy Efficiency. You can send your questions to specialists by email to the editorial office [email protected]. And today on the agenda are garlands.The New Year's rush is in full swing. Streets, offices and apartments sparkle with the lights of New Year's garlands, and at this time it is especially important to provide everything to make the holiday not only fun, but also safe. Today, stores offer a huge number of New Year's garlands - for any, even the most creative Christmas tree, there are a variety of light bulbs colors, sizes and shapes. But the type of New Year's device is not the only criterion that should be followed when choosing a product. Garlands have different purposes: for decorating the interior, for outdoor use, and for the New Year tree. Accordingly, somewhere we will need a “frost-resistant” device, somewhere - with minimal heat transfer, so as not to melt the branches of the artificial New Year's beauty, and somewhere we will have to take into account the moisture resistance of the garland - in case you decide to make your country house look like set for an American Christmas movie.
Garlands with incandescent lamps
This decoration is familiar to us from childhood. Soviet-made garlands came in a set with spare light bulbs and instructions for finding and replacing burnt out ones. The first New Year's garlands were not distinguished by a variety of designs and consisted of two chains with rows of colored lamps, which were also called something completely unfestive - YOG-1. It is worth considering that incandescent lamps heat up quickly and therefore are not suitable for decorating an artificial New Year's tree - they will simply melt the plastic needles. They have been replaced by more modern and safer garlands with LEDs.
LED garlands
Today they are the most popular because they are characterized by low energy consumption and high fire safety. Unlike garlands with incandescent lamps, they hardly heat up. If conventional lamps spend only 10% of the electricity they consume on lighting - the rest goes to heating the device, then LED lamps produce more light with little heat, which makes them many times more economical than incandescent lamps. They can decorate any tree, door or window openings in the apartment, and even the ceiling - there will be no “burnt out” marks left. Like household LED lamps, LED garlands are characterized by minimal energy consumption and have a long service life - up to 50 thousand hours. This is not only a safe, but also an energy-efficient way to decorate an apartment - with them, the price of electricity in New Year's receipts will be lower, albeit a little - this is such a holiday bonus.
The most common types of LED garlands:
Duralight is a flexible transparent plastic cord (or strip) with an LED strip hidden inside. This garland has special marks, and if necessary, it can be cut to the desired size. This type is airtight, resistant to changing weather conditions and is suitable for decorating building facades and street tree trunks. In addition, it is very convenient to create various luminous figures on walls or windows. Due to its durability, duralight is often used not only as a New Year's attribute, but also as a substitute for neon advertising signs.
A cliplight is a wire with low-voltage LED bulbs located at regular intervals - the safest way to create street illumination, therefore it is often used to decorate street trees, decorate parks and building facades. In addition, this garland produces almost no heat, which means that neither a living nor an artificial tree will be harmed.
Playlight or “light rain” - several threads with light bulbs of different colors, with which you can create a luminous curtain. Such garlands are loved for their “waterfall effect” - one of the light modes of the garland.
Beltlight is a cord with sockets for standard low-voltage lamps with E27 socket. This moisture-proof structure is suitable for decorating the facades of buildings and large structures.
Interesting!
Today, there are solar-powered New Year's garlands, which are mainly suitable for street illumination. Such garlands are autonomous - they do not need to be connected to the network. During daylight hours, the battery stores enough energy to operate at night. This is the most economical option in terms of electricity consumption - it consumes no electricity at all. For now, such garlands are available mainly on order, but in the near future they may enter the market for mass consumption.
How to choose a quality garland?
When purchasing a garland, pay attention to the included instructions in Russian, which indicate the technical characteristics of the product and the purpose of the product: is it intended to decorate a street or home, can it be hung on a Christmas tree, including an artificial one.
Ask the seller for a quality certificate for the product, make sure that the device complies with GOST. Also, independently check the quality of the connection of the cord with the control unit and plug, as well as the operation of all light modes of the garland.
It is also worth examining the block for switching such modes - you can even press lightly on it. If the plastic walls have “come apart”, you should not buy a garland.
One more nuance: the distance between the plug and the first light bulb must be at least one and a half meters, and the wire must have good insulation and a cross-section of at least 0.5 square millimeters. The safe power of the garland for placement on the Christmas tree is no more than 50 watts. This information can be found on the label attached to the plug.
Choose the New Year's garland correctly, consider the place where it will be used, do not leave a working device unattended, and then your holiday will definitely turn out to be safe, kind and warm like a family.
New Year's garlands, bright and fashionable! Choosing holiday illumination
What's a Christmas tree without a garland? What's a holiday without twinkling lights? - It's time to decorate the house with Christmas lights. And our tips will help you choose the best New Year's garlands.
How to choose Christmas tree garlands?
When going to buy New Year's illumination, decide in advance: where you will hang the garlands - on the street or in the house, what the length should be, and operating modes. These requirements will vary depending on the technical specifications, permissible voltage and power.
Any New Year's garland, regardless of the manufacturer (Russia, China, Europe), must be accompanied by a certificate confirming the quality of the product and compliance with firefighting GOSTs, as well as instructions in Russian.
New Year's electric garlands: safe and beautiful!
If the garland has a device for controlling music and flashing modes, make sure that the certificate contains a reference to the electromagnetic compatibility protocol. Your new Christmas tree garland should be safe first and foremost.
And, of course, beautiful. Appearance, shape, garland color We select it to suit the style of the festive interior, in accordance with our preferences. The most elegant ones are garlands with figured nozzles and lamps. These are all kinds of stars, snowflakes, bells, little animals and hearts - for every taste.
Street garlands are a holiday for everyone!
Outdoor garlands are produced taking into account operating conditions: they have increased moisture and frost resistance, are tear-resistant and resistant to sunlight.
The cartridge of a New Year's garland for the street must have a special seal that protects against dust and humidity. The outdoor garland packaging is marked IP 23.
Garlands for the street: important!
Choose New Year's garlands for the street with special attention. Outdoor garlands are suitable for decorating indoor spaces, but not vice versa. “Homemade” Christmas tree garlands cannot be used for outdoor decorative lighting - a short circuit is guaranteed.
Electric garlands: safety rules
1. When purchasing, check all the elements of the garland: the connection of the block and wires, the tightness of the insulation, the number of light bulbs, the safety of the sockets and plug. While still in the store, ask the seller to turn on the garland and check that all modes are working properly.
2. The distance from the plug to the last light bulb of the garland must be at least 1.5 m, so that in case of fire there is time to pull the wire out of the socket.
3. Included Christmas garland Spare bulbs should be included. Don't forget to replace them on time. The heating temperature of the garland bulbs should not exceed 65°C.
4. Do not leave New Year's electric garlands unattended. Changes in mains voltage or melted insulation can cause fires. And, of course, an electric garland that is turned on is not a toy for children and pets. Try to hang the garlands in the house at such a height that it is not easy to reach them.
Christmas tree garland power
1. The power consumption of the Christmas tree garland should be no higher than 50-60 W.
2. In the garland between the light bulbs and the plug, there must be an adapter that reduces the voltage in the electrical circuit.
3. The wire of the New Year's garland with flexible durable insulation must have a cross-section of at least 0.5 square meters. mm.
LED garlands: rain, fringe, balls - choose to suit your taste!
LED garlands are a completely different matter. They are extremely fireproof, economical (on average, they consume 5 times less energy than electric ones) and are no less effective. True, the cost will be 2-3 times more expensive.
The service life of LEDs is quite long. The LED garland will last for more than one New Year's holiday, without failures or replacement of elements. If one LED fails, this will not affect the operation of the entire garland.
New Year's LED garlands are very light - to reduce weight, the wires in them are made thin. The LEDs do not heat up during operation.
The only “disadvantage” is that LED garlands require more careful handling. It is advisable not to drop fragile LEDs or subject them to mechanical stress.
The range of LED garlands allows you to create the most incredible holiday backdrop. The decoration of the house will be a rain of light, a waterfall, fringe, shining threads and icicles. LED garlands in the form of multi-colored balls look very elegant. Great for outdoor decoration led curtains- real light fireworks.
LED garlands can be used not only on New Year's Day. This is an excellent option for decorative lighting for your home or office. The section of the Catalog "Electric lighting. Lighting equipment" will help you choose products.
- The wires of the garland also vary in color. A green Christmas tree has green wires, but what if your Christmas tree has an unusual silver or white outfit? Choose a Christmas tree garland with clear or white wires.
- How to hang a garland on a Christmas tree? Starting from the crown, from top to bottom, in a circular motion. At the same time, make sure that the cord does not get tangled in the branches, and that the bulbs are directed outward and not towards the trunk of the tree. First we hang the garland, and then the Christmas tree decorations and tinsel.
- What if the tree rotates? To avoid tangling the cord, choose a Christmas tree spinner with a garland outlet that will rotate with the tree. The LED garland can be powered by a battery and mounted on the trunk.
New Year's garlands on the window
- LED garlands are well suited for decorating windows, as well as chandeliers and lamps, mirrors or picture frames. Choose the size of the garland for the window according to the perimeter of the frame. Flickering lights will create a magical atmosphere of comfort in your home. Just don’t forget about simple safety rules (see above).
DIY New Year's garland
There is no way to decorate your home with electric or LED garlands? This is a great opportunity to show your imagination - replace them with homemade garlands made from paper, pine branches, ribbons, tinsel and bells, fruits and sweets. After all, the most joyful holidays are ahead!
As always, New Year's holidays are characterized by peak loads in electricity consumption for the population and a decrease in consumption for industrial enterprises. Most of the city's enterprises do not work in the first days of January, during the so-called “New Year holidays.” The holiday maximum consumption is recorded after the start of work of some enterprises after January 4th.
Energy consumption during the New Year holidays – by population
Frosty weather has a great influence on the level of consumption; the widespread use of heating devices contributes to an increase in the load of city residents.
Electricity consumption on holidays for residents consists mainly of preparing the festive table; in this case, one should not forget that energy savings for the New Year can be achieved on holidays and at night by homeowners with a special meter installed with the current two-rate tariff.
Another point that energy workers pay attention to is the operation of the TV, which can be turned on in many families throughout the night.
Urban electricity consumption
One of the most significant objects of electricity consumption on an urban scale is the consumption of electricity by city Christmas trees.
Despite the fact that LED garlands are used everywhere, and they are distinguished by the presence of a wide price range from 800 to 18,000 rubles. depending on the length and configuration, lamp garlands are added to them so that the cost is significantly less although they consume much more energy
The average power of a garland used to decorate, for example, a central city square, reaches 15 kW/hour, although the power range can vary from 5 to 40 kW/hour.
New Year's garlands are hung from December 10 to January 14 and are constantly on from 17:00 pm to 10:00 am the next day.
Calculation of electricity consumption by a city Christmas tree
Formula for calculating consumption of 1 New Year's garland per day
P (consumption) = N avg. power x t.
If N = 15 kW/h
t = 17 hours, then it turns out 15 x 17 = 255 kW
Total electricity consumption P total = P x n
Where P day is the electricity consumption of one garland per day
n – The number of city Christmas trees, individually for each city, can reach an average of 50 pieces. P total. (day) = 255 kW x 50 pcs. = 12750 kW
For 35 days from December 10 to January 14, the total electricity consumption of New Year's Christmas tree garlands is 446,250 kW.
Which represents quite impressive consumption figures, the data is taken from static data for some large cities of regional significance for the New Year holiday for 2013/2014. And if you calculate these indicators on a national scale, you get a fairly significant figure.
Energy saving in the New Year
Significantly reduce electricity consumption, perhaps reducing the switching period, that is, using the garland from 18:00 until 6 evening hours, and set the installation and connection date for the garlands not on December 10, but on December 21. This mode of operation of New Year trees is recommended for adoption for the New Year 2015. This method of working Christmas tree garlands was taken on the basis of a statistical survey of the population of cities: Moscow, St. Petersburg, Yekaterinburg, Omsk, Novosibirsk and some others.
I would especially like to note the work of power engineers: peak loads, frosty weather and increased snowfall do not contribute to a festive mood. All substations have been transferred to a special operating mode, and repair teams are constantly on high alert. The duty is carried out around the clock, and the duty officers are required to respond to all signals of malfunctions as quickly as possible.
LEDs are undoubtedly the most economical lighting sources, only sunlight is cheaper. But even despite their efficiency, some specimens can be quite voracious. And yet, how much electricity does an LED consume?
The “gluttony” of a device directly depends on its brightness.
The light-emitting crystal operates at a voltage of 2.8 - 3.5 V (depending on the color of the glow). Inside the diode crystal there is a p-n junction, when current passes through it, light is emitted. How many volts the LED operates from depends on the method of connecting the modules on the matrix. It can be either 3V or 12V.
Consumption depending on LED type
Indicator
Indicator diodes are low-power devices with low current consumption. Already based on the name, it is clear that they are not intended for lighting, but to indicate performance.
The current consumption of products of this class does not exceed 20 mA; at a voltage of 3V per hour, the electricity consumption during their operation will be only 0.06 W or a little more than 0.5 kW per year of continuous glow.
Lighting
Unlike indicator models, for models intended for lighting, the area of the p-n junction, and, accordingly, the area of the light-emitting surface and brightness, is significantly higher. The current consumption of the crystal can be 150-300 mA, with a supply voltage of 3.3V this is from 0.5 to 1 W.
Powerful diodes may contain several elements on one matrix. The power of the LED matrix used in spotlights can reach several hundred watts.
Supply voltage for LED devices
Regardless of the brightness and power of the module, they are all assembled from LED matrices, which are designed for 3.3V power supply. For high-power modules, various combinations of connections with power supply from 12V to 24V are used. This is a necessary measure to reduce the current load.
Consider the following situation:
A 50W light source is required. To create it you will need fifty one-watt modules. If they are all connected in parallel, the supply voltage will be only 3.3 V, but the current in the circuit will reach 50 x 0.3A = 15 Amperes. This is very, very much.
All electrical appliances in the apartment, when turned on at the same time, rarely require more than 10-15 Amperes. High current strength leads to significant heat generation through the conductors, and to power such a unit you would need a finger-thick multi-core copper cable.
To reduce the current in the circuit, the LED modules are connected in series. In the classic connection diagram, the device discussed above will consist of eight stages, consisting of six LEDs connected in series with a supply voltage of 24V. Then the load power will be only 8 x 0.3A = 2.4 A. And this is not much more than the power of an ordinary mobile phone charger.
Supply voltage for household devices using diodes
LED flashlights
LED lights vary significantly in brightness and power. Therefore, it is difficult to say exactly how many volts there are in an LED light bulb.
An ordinary household flashlight has a bright 3.3 V diode installed. Thanks to the use of special circuits that increase the voltage, they comfortably operate from one 1.2 V AA battery or a 1.8 V battery.
How many volts are the LEDs in high brightness flashlights? Signal lights for special purposes are equipped with special diode matrices with a supply voltage of 3.3V - 4.7V and a current of up to 2000mA.
Powerful 3.7V lithium batteries are used to power them.
LED strips
The supply voltage of the tape and its power depend on the type of LEDs used.
| LED type | Number of diodes per linear meter, pcs. | Supply voltage, V | Load current, A | Power 1m, W |
|---|---|---|---|---|
| 3528 | 60 | 12 | 0,4 | 4,8 |
| 3528 | 120 | 12 | 0,8 | 9,6 |
| 3528 | 240 | 12 | 1,6 | 19,2 |
| 5050 | 30 | 12 | 0,6 | 7,2 |
| 5050 | 60 | 12 | 1,2 | 14,8 |
| 5050 | 120 | 12 | 2,4 | 29 |
| 5050 | 240 | 24 | 2,4 | 58 |
