Parting 

Smooth turning on and off of LEDs is a simple circuit. Smooth turning on of the LEDs with your own hands. Soft turn off LEDs

The ever-expanding field of application of perfectly working LEDs opens up additional possibilities for consumers. One feature that highlights the benefits of LED luminaires is the smooth turning on of the LED, which greatly expands their design possibilities.

Prospects for the use of smooth ignition of LEDs

Unusual layouts of LED lamps are increasingly used in the automotive industry, in the design of buildings and premises, creating an indescribable atmosphere of the play of light at various public events. Given the ability to independently mount the smooth turn on of the LED, in the coming years we can expect even more of their distribution. Even a simple scheme for smoothly lighting up and turning off LEDs significantly increases the comfort of their use:

  • the backlight on the devices turns on / off smoothly, without blinding the driver at night;
  • the light in the cabin lights up gradually when the doors are opened;
  • smooth turning on of the side lighting significantly extends the life of LED-lamps.

It is noteworthy that the device for smooth ignition of LED lamps, with a small power consumption, involves only the parallel installation of a polar capacitor. The capacitance of the capacitor should not exceed 2200 uF, and its positive terminal is soldered to the anode wire of the LED. Negative terminal - connects to the cathode wire.

Benefits of Thyristor LEDs

An anecdote is circulating around the network related to the fact that in response to the question whether the light on the modem is blinking, the user replied that the light is blinking, but this is not a light, but a thyristor LED, which confused the provider’s technical support workers, since such LEDs are simply can not be.

The thyristor can only play the role of a kind of key that controls a powerful load, as well as a switch. The definition of a thyristor LED came about after luminaire manufacturers replaced the expensive diode bridge used to drive the LED. Having created a device consisting of 2 thyristors connected in parallel-opposite way, it was possible to get rid of the diode bridge. Due to the fact that such a kind of thyristor LED was used, the price of LED lamps has decreased significantly and has become acceptable to the buyer.

The properties of an electronic key allow you to create not only a smooth turn on of LEDs - thyristors are also used in circuits that provide a gradual on / off even simple incandescent lamps (special switches). Considering the reasonable price of LED luminaires without a diode bridge, the smooth switching on and off of LEDs on a thyristor significantly expands the scope of this modern and efficient means of illumination and lighting.

Smooth ignition and attenuation can be done by yourself

The so-called polite lighting in a car is referred to as a smooth ignition and attenuation of LEDs or their boards. It is necessary to prevent accidental blinding. The smoothness of inclusion makes the light source visually spectacular. The article contains several options for circuits that will help to equip smooth lighting not only in the car interior, but also inside the headlights.

On the Internet, there is an abundance of schemes for smooth turning on and fading LEDs (with voltage from 12V) that you can do yourself. All of them have certain advantages and disadvantages, different levels of complexity, as well as differences in the quality of the electronic circuit.

Often, there is no point in building bulky boards with expensive parts and other content. It is worth noting that smoothly turning on the LED on one transistor, as well as turning it off, is technically possible. Only a single low-wire transistor will be sufficient to correctly and gradually activate the LED chip. The following is a circuit that is easy to implement and does not require expensive materials. Switching on and off in it is carried out by means of a positive drive.

When the voltage is applied, current flows through the resistor R2 and optimizes the capacitor C1. It is worth considering that the voltage in the capacitor is not able to change instantly, and this plays into the hands of the smooth opening of the transistor VT1. The gate current that continues to rise (pin 1) flows through resistor R1 and also builds up a positive potential at the drain itself (pin 2) of the transistor. As a result, a smooth activation of the LEDs occurs. When the power is deactivated, a break occurs in the functioning electrical circuit along the plus (control). In turn, the capacitor gradually discharges, and gives up its energy to R1 and R3 (resistors). The discharge and its speed determines the value of the resistor R3. As the resistance increases, the accumulated energy will go to the transistor. This means that the decay process will take longer. In order to be able to adjust the time for full switching on and deactivation of the voltage, the circuit can be diversified with resistors R4, as well as R5. Despite this, for correct operation, this circuit is best used with resistors R3 and R2 with a small working rating.

It is worth considering that each of the circuits can be folded independently even on a small board. It is necessary to consider the elements of the scheme in more detail. The main component of the control is the n-channel transistor IRF540. A transistor is a semiconductor type device that is capable of generating or amplifying oscillations. The drain voltage of the transistor can reach 23A, as well as 100V - the drain-to-source voltage. Instead of the transistor indicated in the circuit, you can use KP540 (an analogue of domestic). For the ignition of the LEDs and the smoothness of their shutdown, the resistance R2 is responsible, the value of which should not exceed 30-68 kOhm. It is worth noting that a resistor is a component of electrical circuits of a passive type, which is characterized by a variable or a certain indicator of electrical resistance. The main function of a resistor is to linearly convert voltage to current and vice versa, and so on.

For smooth attenuation (switching off) resistance R3 is responsible with an operating range of 20-51 kOhm. In order to set the gate voltage, there is a resistance R1, the value of which is 10 kOhm. The capacitance of capacitor C1 (minimum) must reach 220 microfarads with a maximum voltage of about 16 V. If the capacitance is increased to 470 microfarads, then the time to completely turn off and light up the LED will also increase. In the case of buying a capacitor that works with a high voltage, you will need to increase the board itself.

Management and its adjustment by "minus"

To control the above scheme by minus, it is necessary to carry out its revision. For example, you should replace the transistor with a "p-channel", IRF9540N is suitable for this. Further, the output to the negative of the capacitor must be connected to the point of the three resistors, which is common to them. The positive output should be closed to the source of VT1. The circuit to be finalized will have a reverse polarity in its power supply, while the positive contact will be replaced by a negative one during control.

Arduino: the secrets of working with it

Arduino is a tool for creating various electronic devices, designed for non-professional users. We are talking about the design of robotics, as well as automation systems. Arduino-based devices can receive signals from various sensors and control actuators.

The Arduino is a small board equipped with individual memory and processor that interacts with their environment. This feature significantly distinguishes such a device from a PC that does not leave the framework of the virtual world. In addition, Arduino is able to work together with a computer or in standalone (individual) mode.

There are several dozen contacts on the device board. It is to them that you can connect: sensors, LEDs, expansion cards, motors, etc. It is worth downloading an application for Arduino or a sketch into the processor itself, it is able to take all readings, as well as control devices according to a given algorithm. It is worth noting that the outputs on the Arduino board are called Pin, so after uploading the sketch it will become clear how to work with such a tool.

Is it possible to smoothly turn on the LED on arduino? To begin with, it is worth using a simplified sketch for smooth ignition of LEDs. The brightness of the LEDs will be changed by PWM. To do this, you will need the following components:

  1. Arduino Uno board;
  2. Light-emitting diode;
  3. Breadboard;
  4. 220 ohm resistor;
  5. Wires.

It is worth knowing that AnalogWrite (function) is used to fade and slowly light up the LED. It is AnalogWrite that uses pulse width modulation (PWM). It allows you to activate and deactivate a digital pin at high speed, accumulating a slow decay process.

To connect an LED to Arduino, you need to connect its longer leg (anode) to digital pin number 9, which is located on the board, using a 220 ohm resistor. Then, the shorter leg of the LED (cathode with a negative charge) should be directed towards the ground.

led-svetodiody.ru

Scheme of smooth switching on of incandescent lamps (UPVL) 220v, 12v


Any economical owner of a house or apartment strives to rationally use electrical energy, since its prices are quite high. So, for example, if an ordinary incandescent lamp is used incorrectly, it will regularly “burn out”. Therefore, in order for it to serve you much longer, experts recommend using devices such as soft start devices. You can also make such a block yourself using a specific scheme.

The principle of operation of UPVL

With a sharp flow of electricity, the incandescent lamp wears out very quickly and the tungsten filament burns out. But if the temperature regime of the filament and the electric current is approximately the same, then the process will be stabilized and the lamp will not burn out. In order for the light sources to work as expected, you must have a special power supply.

Thanks to a special sensor, the filament will heat up to the required temperature, and the voltage level will increase to a point specified by the user. For example, up to 176 Volts. In this case, the power supply will help to significantly increase the life of the lamp.


Lamp soft start device

The protection unit has one drawback - in the room the light will burn much weaker.

In the event that the voltage is 176 V, then the lighting level will decrease by about two-thirds. Therefore, experts recommend purchasing powerful lamps so that the quality of light is normal. Currently, there are special soft start units (UPVL) for incandescent lamps, which differ in various power parameters. Therefore, before buying a unit, you need to make sure that it can withstand large surges or voltage drops in the mains. Such a device must necessarily have an additional margin, while it will be quite enough for the voltage in your power supply to be about 30 percent greater than the flow of surges.

You need to know that the higher the standard indicator, the larger the dimensions of the power supply. Currently, you can purchase a power supply with a capacity of 150 to 1000 watts.

Types of power supplies and their characteristics

Today, there are many different devices for smooth switching LN. The most requested are:


Scheme

In order to properly use the soft start blocks of the LC, it is necessary to use special electrical circuits. Thanks to such schemes, you can easily understand how this device works and is arranged from the inside, as well as how it needs to be operated.


Scheme for smooth switching on an incandescent lamp

Usually, when connecting such a device, experts use the simplest and easiest version of the circuit. Sometimes they use a special scheme with the introduction of simisters. Also, in addition to blocks of this type, you can take field-effect transistors that work similarly to soft-start devices.


The second scheme for the smooth switching on of incandescent lamps

Also, in order to be able to control the voltage in the soft start device, you can use automatic devices.

What is a thyristor circuit

Thyristor circuit for smooth turning on the lamp

The rectification bridge circuit (Fig. VD1, VD2, VD3, VD4) uses a light bulb (Fig. EL1) as a load and a current limiter. The rectifier arms are equipped with a thyristor (fig. VS1) and a shifting circuit (fig. R1, R2 and C1). Also, the diode bridge is installed due to the specification of the operation of the thyristor device.

After the voltage is applied to the circuit, the electric current begins to flow through the filament and enters the bridge, and then the electrolyte is charged through the resistor. When the limit of the opening voltage of the thyristor is reached, it begins to open and then the current from the light bulb passes through it. As a result, the tungsten filament heats up gradually and smoothly. The period of its heating will depend on the capacitance of the capacitor and resistor located in the circuit of the device.

What is remarkable about the triac

Such a circuit has fewer parts due to the use of a triac (Fig. VS1), which serves as a power switch.

Triac circuit for smooth switching on lamps

An element such as a choke (Fig. L1), which is designed to remove various interferences that appear during the opening of the power key, is allowed to be removed from the common circuit. (fig. R1) The resistor is a current limiter that is fed to the main electrode (fig. VS1). The circuit that sets the time is made on a resistor (Fig. R2) and a capacitance (Fig. C1), powered by a diode (Fig. VD1). This scheme works the same as the previous one. When the capacitor is charged to the level of the opening voltage of the triac, it begins to open, and then an electric current flows through it and the light bulb.


Scheme for smooth switching on incandescent lamps

In the photo below we can see the triac regulator. Such a device, in addition to adjusting the power in the load, also provides a smooth supply of electric current to the light bulb when it is turned on.


Soft start device for incandescent lamps

Scheme of operation of the block on a specialized microcircuit

The microcircuit type kr1182pm1 was specially created by specialists for the construction of various phase regulators.


Soft start circuit on a specialized microcircuit

In this case, it happens that with the help of the microcircuit itself, the voltage is regulated at the source, which has a power of up to 150 watts. And if you need to control a stronger load system and dozens of lighting fixtures at the same time, then an additional power triac is simply included in the control circuit. In the figure below we can see how this happens.


Scheme of smooth switching on with a power triac

The use of soft start units does not end only with conventional lamps, as experts recommend using them together with halogen lamps with a power of 220 V.

It's important to know! With fluorescent and LED lamps (LED), such blocks cannot be installed. This is due to the fact that there is a different technique for developing circuits, as well as the principle of operation and the presence of each lighting device with its own source of measured heating for fluorescent lamps or there is no need for such regulation of LED lamps.

Soft start device (UPVL) for incandescent lamps in 220v and 12v

To date, a large number of different models of UWL are produced, which differ in function, cost and quality. The device, which is sold in specialized stores, is connected in series to a 220 V light source. We can see the diagram and the appearance of the device in the photo below.


Scheme of a soft start device for 220 V lamps

If the power supply of the lamps is 12 or 24 V, then the device must be connected in front of the step-down transformer also in series to the initial primary winding.

The device must correspond to the load that will be connected with a certain margin. To do this, you need to calculate the number of fixtures and their total power.

Since the device is small in size, the UPVL can be placed under a chandelier, in a socket box or in a connection box.

Dimmers or dimmers

It is economically profitable and rational to use devices that create a smooth switching on of lamps, as well as provide the process of regulating their degree of brightness. Dimmers of various models can:

  • Set programs for lighting fixtures;
  • Smoothly turn on and off the lamps;
  • Controlled by remote, voice commands or claps.

When purchasing this device, you must immediately make a choice in order to know what functions are required, and not to buy an expensive device for a lot of money.

Before installing the dimmer, it is necessary to determine the method and place for controlling lighting fixtures. To do this, it will be necessary to mount the wiring of the appropriate type.

Connection schemes can be of varying degrees of complexity. In any case, you must first turn off the voltage from a certain area.

In the figure, we showed the simplest connection scheme. Here, instead of a simple switch, you can make a dimmer.


Wiring diagram for a dimmer in a lamp power supply

The device is connected to the break of the L-wire with a phase, and not N-zero. Between the zero and the dimmer is a lighting device. Connecting to it is serial.

Figure (B) represents a circuit with a switch. The connection process remains the same, but a simple switch is added here. It is usually installed near the door in a certain gap between the phase and the dimmer itself. Near the bed there is a dimmer switch that allows you to control the lighting while lying down. When a person leaves the room, the light turns off, and when a person enters back, the lamp is started with the same degree of brightness.

In order to control a chandelier or other lighting device, you can take two dimmers, which will be located in different corners of the room (Fig. A). Between themselves, two devices are connected through a junction box.


Incandescent lamp control circuit: a - with two dimmers, b - with two pass-through switches and a dimmer

Thanks to this connection system, you can adjust the degree of brightness from different places independently of each other, but you will need to install more wires.

Pass-through switches are used to turn on lamps from various places in the room (Fig. B). Also, at the same time, you must turn on the dimmer, otherwise the fixtures will not respond to the switches.

Characteristics of dimmers:

  • The dimmer saves only 15% of electricity, and the rest is used by the regulator.
  • Devices have a high degree of sensitivity to an increase in temperature. Therefore, they cannot be operated at temperatures above 27°C.
  • The degree of load should not be less than 40 W, since the life of the regulator is significantly reduced.
  • Dimmers must be used only for those types of devices that are recommended by the manufacturer and are written in the passport.

Video: UPWL device

UPVL can significantly increase the life of halogen lamps and incandescent lamps. These are small and inexpensive devices that you can buy at any store and install yourself, having a certain scheme and strictly following the instructions of the manufacturers.

www.techznatok.com

Do-it-yourself incandescent lamp smooth switching scheme


During the ongoing burnout of incandescent lamps, including on the landing, several schemes for protecting incandescent lamps on the Internet were implemented. Their use gave a positive result - the lamps have to be changed much less frequently. However, not all implemented device schemes worked "as is" - during operation, it was necessary to select the optimal set of elements. In parallel, a search was made for other interesting schemes. As you know, the smooth switching on of incandescent lamps increases their service life and eliminates current surges and interference in the network. In a device that implements this mode, it is convenient to use powerful field switching transistors. Among them, you can choose high-voltage, with an operating voltage at the drain of at least 300 V and a channel resistance of not more than 1 ohm.

Scheme for smooth switching on an incandescent lamp No. 1


The author gives two schemes for the smooth start of lamps. However, here I want to offer only a circuit with the optimal operating mode of the field-effect transistor, which allows it to be used without a radiator with a lamp power of up to 250 watts. But you can also study the first one - which is simpler in that it is included in the break of one of the wires. Here, at the end of the capacitor charging, the drain voltage will be approximately 4 ... 4.5 V, and the rest of the mains voltage will drop on the lamp. In this case, the transistor will release power proportional to the current drawn by the incandescent lamp. Therefore, at a current of more than 0.5 A (lamp power of 100 W or more), the transistor will have to be installed on a radiator. To significantly reduce the power dissipated by the transistor, the machine must be assembled according to the diagram below.

Scheme for smooth switching on an incandescent lamp No. 2


A diagram of a device that is connected in series with an incandescent lamp is shown in the figure. The field-effect transistor is included in the diagonal of the diode bridge, so a pulsating voltage is supplied to it. At the initial moment, the transistor is closed and all the voltage drops across it, so the lamp does not burn. Through the diode VD1 and the resistor R1, the charging of the capacitor C1 begins. The voltage on the capacitor will not exceed 9.1 V, because it is limited by the Zener diode VD2. When the voltage on it reaches 9.1 V, the transistor will start to open smoothly, the current will increase, and the drain voltage will decrease. This will cause the lamp to light up slowly.


But it should be noted that the lamp will not start to light up immediately, but some time after the switch contacts close, until the voltage on the capacitor reaches the specified value. Resistor R2 is used to discharge the capacitor C1 after the lamp is turned off. The drain voltage will be negligible and at a current of 1 A it will not exceed 0.85 V.
When assembling the device, 1N4007 diodes from spent energy-saving lamps were used. The zener diode can be any low-power one with a stabilization voltage of 7 ... 12 V.

I found a BZX55-C11 at hand. Capacitors - K50-35 or similar imported ones, resistors - MLT, S2-33. The adjustment of the device is reduced to the selection of a capacitor to obtain the required lamp ignition mode. I used a 100 microfarad capacitor - the result was a pause from the moment it was turned on until the moment the lamp was ignited in 2 seconds.

It is also important that the lamp does not flicker, as was observed in the implementation of other schemes.


This device has been working for a long time and the incandescent lamps have not yet had to be changed.

usamodelkina.ru

Smooth turning on and off of LEDs

This article will consider several options for implementing the idea of ​​​​smooth turning on and off the LEDs for backlighting the instrument panel, cabin light, and in some cases more powerful consumers - dimensions, low beam, and the like. If your instrument panel is illuminated with LEDs, when you turn on the dimensions, the illumination of the instruments and buttons on the panel will light up smoothly, which looks quite impressive. The same can be said about the interior lighting, which will light up smoothly, and fade out smoothly after closing the car doors. In general, a good option for tuning the backlight :).

The control circuit for smooth switching on and off the load, controlled by the plus.

This circuit can be used to smoothly turn on the LED backlight of the car dashboard.

This scheme can also be used for smooth ignition of standard incandescent lamps with low power spirals. In this case, the transistor must be placed on a radiator with a dissipation area of ​​about 50 square meters. cm.

The circuit works as follows. The control signal enters through the 1N4148 diodes when voltage is applied to the "plus" when the parking lights and ignition are turned on. When any of them is turned on, a current is supplied through a 4.7 kΩ resistor to the base of the KT503 transistor. At the same time, the transistor opens, and the capacitor begins to charge through it and the 120 kΩ resistor. The voltage across the capacitor gradually increases, and then through the 10 kΩ resistor it enters the input of the IRF9540 field-effect transistor. The transistor gradually opens, gradually increasing the voltage at the output of the circuit. When the control voltage is removed the KT503 transistor closes. The capacitor is discharged to the input of the IRF9540 field-effect transistor through a 51 kΩ resistor. After the capacitor discharge process is completed, the circuit stops consuming current and goes into standby mode. The current consumption in this mode is negligible. If necessary, you can change the ignition and decay time of the controlled element (LEDs or lamps) by selecting the resistance values ​​​​and the capacitance of the 220 microfarad capacitor.

With proper assembly and serviceable parts, this circuit does not need additional settings.

Here is a printed circuit board option for placing the details of this circuit:

Scheme of smooth switching on and off of LEDs.

This circuit allows you to smoothly turn on / off the LEDs, as well as reduce the brightness of the backlight when you turn on the dimensions. The latter function can be useful in case of excessively bright illumination, when in the dark the instrument illumination begins to blind and distract the driver.

The circuit uses a KT827 transistor. The variable resistance R2 is used to set the brightness of the backlight in the switched on dimensions mode. By selecting the capacitance of the capacitor, you can adjust the time for the LEDs to light up and go out.

In order to implement the function of dimming the backlight when the dimensions are turned on, you need to install a double switch for the dimensions or use a relay that would work when the dimensions are turned on and close the switch contacts.

Soft turn off LEDs.

The simplest circuit for smooth fading of the VD1 LED. Well suited for the implementation of the function of a smooth fading of interior light after closing the doors.

Almost any diode VD2 is suitable, the current through it is small. The polarity of the diode is determined in accordance with the figure.

Capacitor C1 is an electrolytic, large capacity, we select the capacity individually. The larger the capacitance, the longer the LED burns after the power is turned off, but you should not install a capacitor with too large a capacity, as the contacts of the limit switches will burn due to the high charging current of the capacitor. In addition, the larger the capacitance, the more massive the capacitor itself, there may be problems with its placement. Recommended capacitance 2200uF. With such a capacity, the backlight fades within 3-6 seconds. The capacitor must be designed for a voltage of at least 25V. IMPORTANT! When installing the capacitor, observe the polarity! An electrolytic capacitor may explode if the polarity is reversed!

This scheme it is applied for Soft turn on LED backlight car dashboard. The control signal is positive. The figure shows a diagram of the smooth ignition of the LED backlight.

If necessary, it can be used for smooth ignition and incandescent lamps of low power. Only in this case it is necessary to equip the transistor with a radiator with a dissipation area of ​​about 50 cm2.

How the circuit works:

The control signal does not come through the input diodes 1N4148 from the dimensions and ignition.

When any of them is turned on, the current begins to flow through the 4.7 K resistor to the base of the KT503 transistor. The transistor opens and through it and the 120 K resistor begins to charge the 220 uF capacitor.

At the same time, the voltage on it gradually increases, through a 10 K resistor, entering the input of the IRF9540 field-effect transistor.

The transistor gradually opens gradually increasing the voltage at the output of the circuit.

When the control voltage is turned off, KT503 closes.

The capacitor is discharged to the input of the IRF9540 through a 51K resistor.

After the capacitor is discharged, the circuit stops consuming current and goes into standby mode. The current consumption in standby mode is negligible. If necessary, change the ignition and decay time, you can select the resistance values ​​​​and the capacitance of the capacitor is 220 microfarads.

The scheme does not need additional settings. With proper installation and serviceable parts, the circuit starts working immediately

The figure shows a variant of a printed circuit board. It is most convenient to make a board using a laser ironing method from textolite 2 mm thick.

In the photo is a completely finished device

Surely a lot of people would like to bring something new to their car. Today we will consider how to make small design changes to the backlight of a car .... or maybe not a car, you can also control the LED strip, for example, in interior lighting

Our device will smoothly turn on and off the load, produce smooth ignition.

How it works

We connect a +12 volt power supply to VCC +. We connect the control plus to REM, specifically in the car it will be the plus of the ignition. With LED contacts, everything should be clear, "+" and "-" LEDs.

In the T1 circuit, the BC817 transistor is a domestic analogue of the KT503. Transistor T2 - IRF9540.

If you want to increase the ignition time, you need to increase the value of R2, to reduce accordingly, lower it. To control the damping time, a similar operation must be done with the resistor R3.

To minimize the board, I used SMD resistors, and for convenience I used terminal blocks.

The boards are made by LUT technology. And after the done manipulations, we get a compact and useful device:

Smooth turning on and off of LEDs with your own hands

What soft start, otherwise ignition LEDs I think they all represent.

Let's analyze in detail smooth turning on LEDs with your own hands.

The LEDs should not immediately light up, but after 3-4 seconds, but initially do not blink or glow at all.

Device Diagram:


Components:

■ Transistor IRF9540N
■ Transistor KT503
■ Rectifier diode 1N4148
■ Capacitor 25V100µF
■ Resistors:
- R1: 4.7 kOhm 0.25 W
- R2: 68 kOhm 0.25 W
- R3: 51 kΩ 0.25 W
- R4: 10 kΩ 0.25 W
■ One-sided fiberglass and ferric chloride
■ Screw terminals, 2- and 3-pin, 5 mm

You can change the ignition and decay time of the LEDs by selecting the value of the resistance R2, as well as by selecting the capacitance of the capacitor.


There are many ways to cut textolite: with a hacksaw, metal scissors, using an engraver, and so on.

With the help of a clerical knife, I made grooves along the marked lines, then sawed out with a hacksaw and filed the edges with a file. I also tried to use scissors for metal - it turned out to be much easier, more convenient and without dust.


Next, we sand the workpiece under water with sandpaper with a grit of P800-1000. Then dry and degrease the surface of the board 646 with a solvent using a lint-free cloth. After that, it is undesirable to touch the surface of the board with your hands.


To do this, in the program, when printing at the top left in the “layers” section, uncheck unnecessary checkboxes. Also, when printing in the printer settings, we set high definition and maximum image quality. Using masking tape, glue a page of a glossy magazine / glossy photo paper (if their dimensions are smaller than A4) onto a regular A4 sheet and print our diagram on it. I tried using tracing paper, glossy magazine pages, and photo paper. It is most convenient, of course, to work with photographic paper, but in the absence of the latter, the pages of the magazine will fit perfectly. I don’t advise using tracing paper - the drawing on the board was printed very poorly and will turn out to be fuzzy.


Now we warm up the textolite and apply our printout. Then, with an iron with a good pressure, iron the board for several minutes.


Now we let the board cool completely, after which we lower it into a container with cold water for a few minutes and carefully get rid of the paper on the board. If it does not completely tear off, then roll it slowly with your fingers.


Then we check the quality of the printed tracks, and tint the bad places with a thin permanent marker.


Using double-sided tape, glue the board onto a piece of foam and place it in a solution of ferric chloride for several minutes. The etching time depends on many parameters, so we periodically take out and check our board. We use anhydrous ferric chloride, we dilute it in warm water according to the proportions indicated on the package. To speed up the etching process, you can periodically shake the container with the solution.

After the unnecessary copper has been etched, we wash the board in water. Then, using a solvent or sandpaper, we clean the toner from the tracks.

Then you need to drill holes for mounting the board elements. For this, I used a drill (engraver) and drills with a diameter of 0.6 mm and 0.8 mm (due to the different thickness of the legs of the elements).


Next, you need to irradiate the board. There are many different ways, I decided to use one of the simplest and most affordable. Using a brush, lubricate the board with a flux (for example, LTI-120) and use a soldering iron to tin the tracks. The main thing is not to keep the soldering iron tip in one place, otherwise the tracks may break off when overheated. We take more solder on the sting and lead them along the path.

Now we solder the necessary elements according to the scheme. For convenience inSprintLayotI printed out a diagram with symbols on plain paper and, when soldering, checked the correct arrangement of the elements.


After soldering, it is very important to completely wash off the flux, otherwise there may be short pieces between the conductors (depending on the flux used). First, I recommend that you thoroughly wipe the 646 board with a solvent, and then rinse well with a brush with soap and dry.


After drying, we connect the “permanent plus” and “minus” of the board to the power supply (“we don’t touch the control plus”), then instead of the LED strip we connect a multimeter and check if there is voltage. If at least some voltage is still present, it means that it is short somewhere, the flux may have been washed off badly.



Outcome:

I am satisfied with the work done, although it took a lot of time. The process of manufacturing boards using the LUT method seemed interesting and simple to me. But, despite this, in the process of work, I probably made all the mistakes that were possible. But as they say, you learn from your mistakes.

Such a board for smooth ignition of LEDs has a fairly wide application and can be used both in a car (smooth ignition of angel eyes, instrument panels, interior lights, etc.), and in any other place where there are LEDs and 12V power supply. For example, in the backlight of a computer system unit or decorating suspended ceilings.

Recently I decided to assemble a circuit that would allow me to light up any LED strip (whether in a car or at home) smoothly. I did not reinvent the wheel, and decided a little Google it. When searching on almost every site, I found circuits where the LED load is severely limited by the capabilities of the circuit.

I wanted the circuit to just smoothly raise the output voltage, so that the diodes flare up smoothly and the circuit was necessarily passive (it did not require additional power and would not consume current in standby mode) and would definitely be protected by a voltage regulator to increase the life of my backlight .

And since I haven’t learned how to etch the boards yet, I decided that first I need to master the simplest circuits and use ready-made circuit boards during installation, which, like the rest of the circuit components, can be purchased at any radio parts store.

In order to assemble a smooth ignition circuit for LEDs with stabilization, I needed to purchase the following Components:

In general, a ready-made circuit board is a fairly convenient alternative to the so-called “LUT” method, where almost any circuit can be assembled using the Sprint-Layout program, a printer, and the same textolite. So, beginners should still first master a simpler option, which is much simpler and, most importantly, “forgives mistakes” and also does not require a soldering station.

Having slightly simplified the original scheme, I decided to redraw it:

I know that the transistor and the stabilizer are indicated differently in the diagrams, but it’s easier for me, and it will be clearer for you. And if, like me, you managed to take care of stabilization, then you need an even simpler scheme:

The same, but without the use of the KREN8B stabilizer.

  • R3 - 10K Ohm
  • R2 - 51K Ohm
  • R1 - from 50K to 100K ohm (the resistance of this resistor can control the speed of ignition of the LEDs).
  • C1 - from 200 to 400 microns F (you can choose other capacities, but you should not exceed 1000 microns F).

At that time, I needed two smooth ignition boards:
- for the already made highlighting of the legs.
- for smooth ignition of the dashboard.

Since I took care of the stabilization of the LEDs that illuminate my legs for a long time, I no longer needed Krenka in the ignition circuit.

Scheme of smooth ignition without a stabilizer.

For such a circuit, I used only 1.5 sq cm of the circuit board, which costs only 60 rubles.

Scheme of smooth ignition with a voltage stabilizer.

Dimensions 25 x 10 mm.

The advantages of this circuit is that the connected load depends only on the capabilities of the power supply (car battery), and on the IRF9540N field-effect transistor, which is very reliable (it makes it possible to connect 140W of load through itself at a current of up to 23A (information from the Internet). The circuit can withstand 10 meters of LED strip, but then the transistor will have to be cooled, since in this design it is possible to attach a radiator to the field radiator (which, of course, will lead to an increase in the area of ​​\u200b\u200bthe circuit).