However, I used more powerful components and a different chip.
The datasheet can be downloaded. The LED current is set through a current-sensing control resistor. The output current I is equal to 0.1/Rs. I needed about 300 mA of current for each channel, so I chose a 0.33 ohm resistor. For a current of 350 mA, select a 0.27 ohm resistor.
Each channel is controlled using a PWM signal, such as from an Arduino microcontroller (you will need to solder male/female headers to the board).
You can use input voltage up to 30V and drive 3W/10W/20W LEDs.
Required components:
- Tantalum capacitorsC1, C2, C3 : capacitance 22uF
- D1, D2, D3 ; Schottky diode 2A in SMA package
- L1, L2, L3 : Powerful chokes 68 µH, 0.7A
- R1, R2, R3 : Resistors with a nominal value of 0.33 Ohm, housing 0805.
- 4 x screw clamp, 3.5 mm(available from Tayda Electronics)
- 3x PT4115 drivers.
- 1x 4-pin + 1x 2-pin male header "dad" or "mom".
The photo above shows the fully assembled driver.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad |
|---|---|---|---|---|---|---|
| IC1-1C3 | LED driver | PT4115 | 3 | To notepad | ||
| D | Schottky diode | 2 A | 3 | Any | To notepad | |
| C1-C3 | Capacitor | 22 µF | 3 | Any | To notepad | |
| R1- | Resistor | 0.33 Ohm | 3 | Any | To notepad | |
| D1 | Inductor | 68 µH | 3 | Any for current 0.7 A | To notepad | |
| J1 | Pin connector | 2 pin | 1 | To notepad | ||
| J | Pin connector | 4 pin | 1 | To notepad | ||
| JP1-JP3 | Screw clamp | 2 pin | 3 |
The most optimal way to connect to 220V, 12V is to use a current stabilizer or LED driver. In the language of the intended enemy it is written “led driver”. By adding the desired power to this request, you can easily find a suitable product on Aliexpress or Ebay.
- 1. Features of Chinese
- 2. Service life
- 3. LED driver 220V
- 4. RGB driver 220V
- 5. Module for assembly
- 6. Driver for LED lamps
- 7. Power supply for LED strip
- 8. DIY LED driver
- 9. Low voltage
- 10. Brightness adjustment
Features of Chinese
Many people like to buy from the largest Chinese bazaar, Aliexpress. prices and assortment are pleasing. LED driver is most often chosen due to its low cost and good characteristics.
But with the rise in the dollar exchange rate, it became unprofitable to buy from the Chinese, the cost became equal to the Russian one, and there was no guarantee or possibility of exchange. For cheap electronics, the characteristics are always overestimated. For example, if the power specified is 50 watts, at best this is the maximum short-term power, not constant. The nominal will be 35W - 40W.
In addition, they save a lot on the filling to reduce the price. In some places there are not enough elements that provide stable work. The cheapest components are used, with short term service and low quality, so the defect rate is relatively high. As a rule, components operate at the limit of their parameters, without any reserve.
If the manufacturer is not listed, then he does not have to be responsible for the quality and no review will be written about his product. And the same product is produced by several factories in different configurations. For good products, the brand must be indicated, which means that he is not afraid to be responsible for the quality of his products.
One of the best is the MeanWell brand, which values the quality of its products and does not produce junk.
Service life
Like anyone electronic device The LED driver has a service life that depends on operating conditions. Branded modern LEDs already work up to 50-100 thousand hours, so the power fails earlier.
Classification:
- consumer goods up to 20,000 hours;
- average quality up to 50,000 hours;
- up to 70,000h. power supply using high-quality Japanese components.
This indicator is important when calculating long-term payback. There is enough consumer goods for household use. Although the miser pays twice, and this works great in LED spotlights and lamps.
LED driver 220V
Modern LED drivers are designed using a PWM controller, which can stabilize the current very well.
Main parameters:
- rated power;
- operating current;
- number of connected LEDs;
- degree of protection against moisture and dust
- power factor;
- Stabilizer efficiency.
Housings for outdoor use are made of metal or impact-resistant plastic. When the case is made of aluminum, it can act as a cooling system for electronic components. This is especially true when filling the body with compound.
The markings often indicate how many LEDs can be connected and what power. This value can be not only fixed, but also in the form of a range. For example, 4 to 7 pieces of 1W are possible. It depends on the design electrical diagram LED driver.
RGB driver 220V
Three-color RGB LEDs differ from single-color LEDs in that they contain crystals in one housing different colors red, blue, green. To control them, each color must be lit separately. For diode strips, an RGB controller and power supply are used for this.
If a power of 50W is indicated for an RGB LED, then this is the total for all 3 colors. To find out the approximate load on each channel, divide 50W by 3, we get about 17W.
In addition to powerful led drivers, there are also 1W, 3W, 5W, 10W.
Remotes remote control(DU) there are 2 types. With infrared control, like a TV. With radio control, the remote control does not need to be pointed at the signal receiver.
Assembly module
If you are interested in an LED driver for assembling an LED spotlight or lamp with your own hands, then you can use an LED driver without a housing.
Before you make a 50W led driver with your own hands, it’s worth searching a little, for example, every diode lamp contains it. If you have a faulty light bulb whose diodes are faulty, then you can use the driver from it.
Low voltage
We will analyze in detail the types of low-voltage ice drivers operating from voltages up to 40 volts. Our Chinese brothers-in-mind offer many options. Voltage stabilizers and current stabilizers are produced on the basis of PWM controllers. The main difference is that the module with the ability to stabilize the current has 2-3 blue regulators on the board, in the form of variable resistors.
As technical characteristics of the entire module indicate the PWM parameters of the microcircuit on which it is assembled. For example, the outdated but popular LM2596 according to its specifications holds up to 3 Amps. But without a radiator it will only handle 1 Ampere.
A more modern option with improved efficiency is the XL4015 PWM controller designed for 5A. With a miniature cooling system it can operate up to 2.5A.
If you have very powerful, super-bright LEDs, then you need an LED driver for LED lamps. Two radiators cool the Schottky diode and the XL4015 chip. In this configuration, it is capable of operating up to 5A with voltage up to 35V. It is advisable that it does not operate in extreme conditions, this will significantly increase its reliability and service life.
If you have a small lamp or pocket spotlight, then a miniature voltage stabilizer with a current of up to 1.5A is suitable for you. Input voltage from 5 to 23V, output up to 17V.
Brightness adjustment
To regulate the brightness of the LED, you can use compact LED dimmers that have appeared recently. If its power is not enough, then you can install a larger dimmer. They usually operate in two ranges: 12V and 24V.
You can control it using an infrared or radio remote control (RC). They cost from 100 rubles for a simple model and from 200 rubles for a model with a remote control. Basically, such remote controls are used for 12V diode strips. But it can easily be connected to a low-voltage driver.
Dimming can be analog in the form of a rotary knob or digital in the form of buttons.
RGB LED strips are convenient to use for decorative lighting of shop windows, car interiors, signs... They are easy to work with, unlike simple LEDs, because... The current limiters are already in place, you just need to supply the required voltage. The ability to cut into segments provides flexible installation options.
But what if you want more? what if you need to control each diode individually? You can install an MK, but not every microcontroller alone can handle many three-color diodes, you can try installing it to each one. For such purposes, there are special LED drivers, some of which are equipped with the ability to be controlled by one common, or sequentially passing through the drivers, bus. Somewhere they went further, and such a driver was built directly into an RGB LED, which requires a minimum of external wiring. Next, such diodes connected in series were placed on an LED strip - and in the end we got an addressable LED strip.
As you might guess, the article will focus on the RGB LED driver - WS2811, which are connected in series and controlled via a single-wire data line. And an addressable LED strip based on combined RGB diodes with such drivers.
As you can see in the photo, such an LED strip consists of many series-connected RGB LEDs with built-in WS2811 drivers (small black dot in the middle). From the wiring, such a microcircuit, when powered by 5V, requires only one 0.1 µF capacitor at the power input; a 33 Ohm resistor on the data line is also recommended, which, apparently, the manufacturer missed.
All diodes sit in series on the same line. To change their displayed color and its intensity, you need to send the first diode a message containing an appeal to each of the diodes on the tape. The first driver receives the entire package and transmits it further, minus the last package, which he writes off to his account. The same thing happens with all the remaining LED-driver assemblies. The sending ends with a special RES command, which is highlighted by a long low signal level; upon receiving it, all diodes will apply their new states.
Each packet consists of 24 bits - 8 bits for each channel, resulting in 255 gradations of each color or 16 million colors. Each bit contains a positive and negative half-cycle; a zero or a one is encoded by the duration of the half-cycles.
To work with an addressable LED strip, a controller was assembled based on the PIC16F688 microcontroller and on a specially previously prepared universal board blank (), so I will not give the signet.
This LED strip is very power hungry; a meter with 60 LEDs consumes more than 2 amperes at maximum, so you need a good and powerful power source. You can give it a lower current, but then it will burn with a predominance of red shades.
The firmware was written in haste. The following operating algorithm was implemented: first, the entire package is transferred to the microcontroller from the computer and only after that it displays it. Due to the small amount of RAM in the weak microcontroller, it was possible to implement a buffer for only 60 addressable LEDs with WS2811 drivers. Due to the average UART speed of 38400, the update speed of the entire tape is approximately 50 ms, i.e. The maximum allowable refresh rate was 20 frames/second. Which was enough for me to demonstrate the capabilities of the tape. Generates all effects special program on a PC, which was also written in haste.
Format of commands sent to the controller:
Sending is carried out via UART at a speed of 38400 8N1.
- The first byte is a space (32 ASCII int code)
- The second byte is the length of the transmitted parcel (number of LEDs), from 0 to 60 (transmitted by byte)
- Next, 3 bytes, in GRB order (green, red, blue), transmit PWM values for each LED, starting from the opposite end of the strip.
The controller responds to the start of exchange via UART with an ASCII character ! , upon successful completion of sending the packet with an ASCII character b .
Based on such LED strips, it is possible to implement short videos screens and various installations.
Update dated September 1, 2015
For the convenience of checking the design, I am adding to the article firmware with autonomous smooth sequential pseudo-random transfusion (up to 60 LEDs). If this effect alone is enough, then you can simplify the circuit by removing cp2102 from it.
Problems
