LEDs for DRLs. DIY DRL made from LEDs

For several years now, daytime running lights have become mandatory for installation on cars in the Russian Federation. The market is overflowing with Chinese crafts that do not meet technical requirements and GOST standards. Car enthusiasts were not at a loss and began to actively make DRLs with their own hands.

To make the right LED DRLs, you need to know what requirements apply to them:

• Luminous intensity – from 400 to 800 candelas;
• luminous angle vertically 25 degrees and 55 horizontally;
• The area that emits light must be at least 40 cm2.

Degradation

Example, new on the left, old on the right (2 years of operation)
As it is used, the LED is exposed to influences that negatively affect its characteristics.

Main factors:

1. clouding of the optical part made of silicone;
2. burnout of the phosphor under the influence of temperatures;
3. deformation of the housing due to heating and stress of the housing;
4. crystal degradation.

During crystal degradation, defects appear in which a section of the crystal stops shining, but continues to heat up. At the same time, the leakage current begins to increase, that is, the current passes without emitting light. The worst catalysts for degradation are current higher than rated and elevated temperature. Therefore, you need to be careful when buying dubious specimens, because our Chinese brothers in wisdom can “overclock” LEDs by supplying a current higher than the rated one.

How the device works

The main job of the driver is to create a given current value at the output and maintain it. Any scheme of this type consists of several parts:

• network filter that protects the network from interference;
• capacitor-resistor (RC) or transformer unit to reduce voltage;
• diode bridge for rectification;
• current stabilizer.

A device with an RC filter works like this:

1. A capacitor in an alternating current network performs the functions of capacitance. Together with the bridge, it forms a voltage divider and reduces it to the desired limit. The resistor in its circuit serves for self-charging.
2. The reduced voltage is supplied to the current stabilizer, and from it to the LEDs.

A transformer unit is a device of a key or other type, controlled by a generator. It can be made on specialized microcircuits, high-voltage key transistors, simple elements or on a PWM controller.

This driver works as follows:

• when power is supplied, the bridge straightens it, and it goes to the switches, on which antiphase voltages are created with the help of windings;
• simultaneously with them, the generator is turned on, which generates pulses and starts the driver;
• the keys, turning on alternately, ensure uninterrupted operation of the device through the feedback circuit;
• an alternating voltage appears on the output winding, rectified by a bridge or 1-2 diodes together with electrolytic capacitors;
• Next in the circuit there is a current stabilizer, to which the LEDs are connected.

Description of LED DRLs

Running lights are a type of optics used on the outside of a car body and designed to improve the visibility of the vehicle's dimensions. Today, the use of navigation lights is mandatory. In accordance with international EEC regulations No. 48, navigation light emitters must have an area of ​​at least 25 and no more than 400 cm2. In addition, their aperture level should vary in the range of 400-800 Cd.

Criterias of choice

If you decide to purchase LED DRLs, then doing so today is quite simple, since this type of optics can be found in almost every car store

The main parameter that must be taken into account when purchasing is the aperture ratio, it is important that it is no more than 800 cd, not brighter. Such lighting will allow for good illumination of the road surface and at the same time prevent possible “dazzle” of oncoming drivers.

LED DRLs in cars

It should also be noted that LED running lights should be clearly visible from a distance of one hundred meters, no less. Otherwise, there is a risk of possible communication with the traffic police inspector. Another important parameter is that the upper edge of the running lights should be located above the edge of the low beam. After all, it is thanks to this that the visibility of the car on the road will be excellent.

Advantages and disadvantages

LEDs in daytime running lights have certain advantages:

• automatic activation;
• the vehicle becomes more visible on the road;
• The power of LEDs is quite high, while they consume significantly less energy;
• long service life, which should be at least 5 thousand hours;
• diodes do not affect fuel consumption in any way;
• The modern market offers customers a huge choice.

As for the disadvantages, the main disadvantage of such DRLs is the price, since it is not possible to buy high-quality running lights at a low cost. Installing high-quality LED DRLs that will have a long service life will require additional investment. Moreover, installation and purchase costs can be very high. However, in fact, such optics have excellent characteristics, so they pay for themselves quite quickly (the author of the video is Alexander Kordyukov).

https://youtube.com/watch?v=PpnQEbV2ihM

Also, the disadvantages include the installation of daytime running lights in the absence of connectors. Of course, it is quite possible to solve such a problem, it will just take more time.

The best manufacturers and models

Now let’s briefly look at the main manufacturers of diode DRLs:

1. First of all, I would like to highlight Osram DRL 101 - this model showed excellent ratings from users, in particular, for its original design. No one will be delighted with an LED strip, which cannot be said about light-filled tubes. The color temperature of the devices is 6000K, and each bulb can produce 400 lumens. The power of this model is 7.5 volts per unit.
2. Hella ledayflex. Also quite a popular model, characterized by the presence of five diodes. The use of Hella ledayflex is allowed on absolutely any car. In addition, the consumer has the opportunity to configure the location of the diode elements. The color temperature in this case is the same, but the power is lower - 7.2 volts. The main qualities of Hella ledayflex are originality, as well as strength and reliability.
3. Philips DayLight 4 LED12820WLEDX1. The cost of such devices is significantly lower than the options described above, most likely due to the design, because today no one can be surprised by the installation of traditional “boxes” with diodes. The power of one diode is 1 W, and the total power of the system will be only 8 volts. The only drawback of this option is the luminous intensity of 900 Cd; as we said earlier, the maximum luminous intensity allowed is 800 Cd (the author of the video is TheLadaGranta channel).

The simplest driver on the LD1585CV or LM1084IT chip for self-assembly

Let's look at a driver built on a similar LM 317, which we looked at above. In general, I don’t like drivers without transistors. That's why I don't always use these schemes. Although, to be honest, I haven’t been collecting drivers for a long time, but buying them. It’s easier and no time is wasted. Link to cheap drivers - see at the beginning of the article.

Principle of operation:

R - the resistor sets the current, calculated by the formula: 1.25 / R1.

Those. for a current of 550 mA you need a 2.2 ohm resistor. To calculate resistors, you can use our calculators.

The resistor power is calculated using the formula: 1.56 / R1

Another disadvantage of this scheme is the impossibility of dimming. This is only possible by replacing the resistor. These regulators LD1585CV, or LM1084IT-ADJ are preferable to the standard LM 317, which we discussed above, due to the fact that its voltage drop is higher than 3.5 V. And for LD1585CV, or LM1084IT-ADJ it is from 2.4 V.

The circuit uses a 6.3V or higher capacitor from 10u to 100u.

Required materials and tools

In order to assemble a homemade driver, you will need:

• Soldering iron with a power of 25-40 W. You can use more power, but this increases the risk of overheating of the elements and their failure. It is best to use a soldering iron with a ceramic heater and a non-burning tip, because... a regular copper tip oxidizes quite quickly and has to be cleaned.
• Flux for soldering (rosin, glycerin, FKET, etc.). It is advisable to use a neutral flux - unlike active fluxes (phosphoric and hydrochloric acids, zinc chloride, etc.), it does not oxidize the contacts over time and is less toxic. Regardless of the flux used, after assembling the device, it is better to wash it with alcohol. For active fluxes this procedure is mandatory, for neutral ones - to a lesser extent.
• Solder. The most common is low-melting tin-lead solder POS-61. Lead-free solders are less harmful when inhaling fumes during soldering, but have a higher melting point with lower fluidity and a tendency to degrade the weld over time.
• Small pliers for bending leads.
• Wire cutters or side cutters for cutting long ends of leads and wires.
• Installation wires are insulated. Stranded copper wires with a cross-section of 0.35 to 1 mm2 are best suited.
• Multimeter for monitoring voltage at nodal points.
• Electrical tape or heat shrink tubing.
• A small prototype board made of fiberglass. A board measuring 60x40 mm will be sufficient.

PCB development board for quick installation

Assembling and configuring the driver

The driver components are mounted on a breadboard. First, the LM393 chip is installed, then the smallest components: capacitors, resistors, diodes. Then transistors are installed, and lastly a variable resistor.

It is better to place elements on the board in such a way as to minimize the distance between the connected pins and use as few wires as jumpers as possible.

When connecting, it is important to observe the polarity of the diodes and the pinout of the transistors, which can be found in the technical description for these components. You can also check diodes using a multimeter in resistance measurement mode: in the forward direction, the device will show a value of about 500-600 Ohms.

To power the circuit, you can use an external DC voltage source of 5-24 V or batteries. 6F22 (“crown”) and other batteries have too small a capacity, so their use is impractical when using high-power LEDs.

After assembly, you need to adjust the output current. To do this, LEDs are soldered to the output, and the VR1 engine is set to the lowest position according to the diagram (checked with a multimeter in the “testing” mode). Next, we apply the supply voltage to the input, and by rotating the VR1 knob we achieve the required brightness.

List of elements:

What can you make from LEDs with your own hands?

This is a very interesting question. And if you answer it in detail, it will take a lot of time. The most common use of light diodes is to illuminate suspended and suspended ceilings, a work area in the kitchen, or even a computer keyboard.

Expert opinion Igor Marmazov ES, EM, EO design engineer (power supply, electrical equipment, interior lighting) ASP North-West LLC

“For the operation of such elements, a power stabilizer or controller is required. You can even take it from an old Chinese garland. Many “craftsmen” write that an ordinary step-down transformer is sufficient, but this is not so. In this case, the diodes will blink.”

Stabilizer for diode lamps - you can solder a similar one yourself

Current stabilizer - what function does it perform?

A stabilizer for LEDs is a power source that lowers the voltage and equalizes the current. In other words, it creates conditions for the normal operation of elements. At the same time, it protects against voltage increases or decreases on the LEDs. There are stabilizers that can not only regulate voltage, ensuring smooth attenuation of light elements, but also control color or flicker modes. They are called controllers. Similar devices can be seen on garlands. They are also sold in electrical stores for switching with RGB strips. Such controllers are equipped with remote controls.

The design of such a device is not complicated, and if desired, a simple stabilizer can be made with your own hands. To do this, you only need a little knowledge in radio electronics and the ability to hold a soldering iron.

Connection diagram for daytime running lights on a car

Daytime running lights for a car

The use of light diodes in the automotive industry is quite common. For example, DRLs are manufactured exclusively with their help. But if the car is not equipped with running lights, then purchasing them can hit your pocket. Many car enthusiasts make do with a cheap LED strip, but this is not a very good idea. Especially if the strength of its luminous flux is low. A good solution might be to purchase self-adhesive tape with Cree diodes.

It is quite possible to make DRLs using already broken ones by placing new, powerful diodes inside the old cases.

Important! Daytime running lights are designed specifically to make the car visible during the day and not at night. There is no point in checking how they will shine in the dark

DRLs should be visible in the sun. You can easily make this type of advertising yourself.

Flashing LEDs - what is this for?

A good option for using such elements would be an advertising board. But if it glows statically, it will not attract the attention it deserves. The main task is to assemble and solder the shield - this requires some skills, which are not difficult to acquire. After assembly, you can mount a controller from the same garland

The result is a flashing advertisement that will clearly attract attention

Color music using light diodes - is it difficult to make?

This job is no longer for beginners. In order to assemble a full-fledged color music with your own hands, you need not only an accurate calculation of the elements, but also knowledge of radio electronics. But still, its simplest version is within the capabilities of everyone.

The simplest color music - all you have to do is connect the sound sensor

You can always find a sound sensor in radio electronics stores, and many modern switches have one (light when clapping). If you have an LED strip and a stabilizer, then by running “+” from the power supply to the strip through a similar firecracker, you can achieve the desired result.

Voltage indicator: what to do if it burns out

Modern indicator screwdrivers consist of a light diode and resistors with an insulator. Most often this is an ebonite insert. If the element inside burns out, it can be replaced with a new one. And the craftsman himself will choose the color.

This diode can be easily replaced if desired.

Another option is to make a chain tester. To do this you will need 2 AA batteries, wires and a light diode. Having connected the batteries in series, we solder one of the legs of the element to the positive of the battery. The wires will come from the other leg and from the battery negative. As a result, when shorted, the diode will light up (if the polarity is not reversed).

TOP 3 soldering irons for circuit boards

To simplify the work of soldering the stabilizer, it is advisable to buy a high-quality soldering iron

The stores have units from good and trusted manufacturers that you should pay attention to:

1. Ersa is a German company. The product is very good and reliable, but expensive, and therefore not everyone can afford it for their home.
2. Chinese company Quick. The quality is excellent and the price is reasonable.
3. Luckey. The most budget option. Do not leave the device turned on unattended - it may cause a fire.

A 10 W soldering iron is enough to make a simple microboard. When purchasing, examine the handle - it should not heat up quickly. Wood is an ideal option. Plastic will quickly become hot, hard rubber is heavy, and therefore difficult to work with small parts.

It is advisable to choose a tip made of copper - it is easy to clean off carbon deposits after work. The stings come in different shapes and are sold in sets. This will not be useful for a beginner, but experienced people will find it convenient to use attachments of different configurations.

Voltage stabilizers for cars

So I decided to get busy and make stabilizers for LED interior lighting panels and LED DRLs myself. For what? The fact is that, firstly, I don’t like it when the LEDs “strobe” and secondly, so as not to burn out. The voltage in the car network can jump to 14 V or more.

In general, this is a useful device and in theory it should be so. But not all DRLs contain a stabilizer. I found the diagram on the internet. I etched the boards myself. I covered the future paths with nail polish successfully exposed from my wife.