Now the computer are using the LED screen, which is the LED screen controller is the core computer component, The LED screen controller is also a very large number of types, such as LED display synchronous controller, and LED display asynchronous controller two. They can realize the role of timers, temperature control humidity control, etc. LED screen controller is mainly composed of synchronous controller composition and asynchronous controller composition. Both are realized by transmitting data. controller PCBA
1. LED display controller principle
LED display controller is the control circuit is works according to the line scanning mode, the column control circuit is divided into two categories. The column control circuit, a class of 74LS377 chip as a column drive circuit of the latch, the CPU through the parallel bus to the column drive circuit of the latch to write the word mode data; another class is to use the shift register 74LS595 chip as a column drive circuit of the latch, the CPU through the serial bus to the column drive circuit of the latch to write the word mode data.
Whether the parallel bus control mode or the serial bus control mode, its work process is the first to the data pointer DPTR value, and then accumulator A according to the point of the data pointer DPTR, from the external data memory RAM to read the word mode data. Then, parallel bus, and then to the data pointer DPTR assignment, and then the CPU will be accumulator A in the word mode data, according to the data pointer DPTR pointing to write to the LED array driver circuit of the latch; Serial bus, the CPU will be accumulator A in the word mode data, through the serial port to write to the LED array driver circuit of the latch.
2. LED Controller PCBA Type
(1) Low-voltage LED products high-power controller
Low-voltage LED products are generally designed for voltage 12V-36V, 3-6 LEDs in series per circuit, current limitation by resistor voltage reduction, and current below 20mA per circuit. An LED product consists of multiple circuits of LEDs, the advantages of low-voltage, simple structure, and ease of design; the disadvantages: the product scale is large when the current is very large, and the need to configure low-voltage switching power supply. Due to the limitations of the disadvantages of the product, low voltage makes not possible to transmit power over long distances, are limited to the size of the product is not large, such as signage text, and small patterns. According to this feature, the controller design specifications: 12V choose 75A / 30V MOS power tube control, output current 8A / road; 24-36V choose 60A / 50V MOS power tube control, output current 5A / road. Users can select the controller according to the above specifications of the number of roads, jumping can choose the NE20 low-voltage series, and gradual change in the purchase of NE10 low-voltage series of controllers can be. Note that the LEDs must be a common anode (+) connection method, the controller controls the cathode (-), and the controller does not include a low-voltage power supply.
(2) high-voltage LED product controller
High-voltage LED products designed for AC / DC 220V voltage, the number of LEDs in each circuit is 36-48 in series, with each circuit current 20mA or less, there are two types of current limiting methods, one is resistive current limiting, this way of resistor power consumption, it is recommended to use every 4 LEDs in series to connect a 1/4W metal-mode resistor, even distribution of heat dissipation, this connection is currently the most stable and reliable; the other is resistor-capacitor series connection limiting method; the other is resistor-capacitor series connection limiting method, the other is resistor-capacitor series connection limiting method. One is resistor-capacitor series current limiting, in this connection most of the voltage drops in the capacitor, resistor power consumption is small, and can only be used in a stable long bright state, if the flash capacitor energy storage, but the voltage is doubled, the LED is easy to damage. Where the use of the controller LED must use the resistor current limiting method, LED generally one meter per circuit, power 5W, three-color power 15W per meter. commonly used gradient controller NE112K control DC 1200W, NE103D AC load 4500W DC load 1500W, if the tube flashing unit more than the use of the NE112K, if you only need to overall flash on the use of the NE103D. NE103D, if the use of gradient, pay attention to load matching, neon and LED light distribution characteristics are not the same, the same circuit can not be mixed with different types of loads.
(3) Serial Controller for Low Voltage LED Products
Low-voltage LED product serial controller is characterized by the number of control paths, and the use of serial signal transmission to achieve the purpose of control, general 512 units of control only need 4 control lines, serial LED controller needs to be equipped with a register in the the the the LED light source board, the controller can choose the model NE040S controller, the controller’s maximum capacity of 4096KBit, if the load 512 units of LED can achieve a maximum of 8192 units. The maximum capacity of this controller is 4096KBit, if loaded with 512 units of LEDs, it can realize a maximum of 8192 frames.
3. What are the LED PCBA controllers?
24 keys LED controller DC12V6A72W 24 keys LED controller with IR infrared remote control, remote control distance is ≤ 10 meters, with 16 monochrome + gradient, jump function, can be connected to the RGB length of 5 meters 60 lamps/meter. Its company has advanced R & D testing instruments and imported lamp bead packaging equipment, several fully automatic patches, and an assembly production line, using a unique, personalized appearance design, imported LED chips, and scientific lamp structure, matching the high degree of optical transmittance, reflective lenses, and unique heat dissipation processing and independent research and development and production of the driver and power supply, to ensure the quality of the product. Its market price is 20 yuan/pc.
(2) 360W12Vled controller
360W12Vled controller power supply voltage of 5-12v, a variety of modules, light bars, and perforated lights can be universal, the connection mode for the common sun, the external dimensions of 126 * 72 * 25mm, the weight is 220g, the output current of “10A each way, the output power of 360W. is a long price of $ 32.
(3) 44 keys led controller upgraded version
44 keys LED controller infrared controller (upgraded version) using an advanced computer control chip, used to control a variety of LEDs as the light source lamps and lanterns; has the advantage of price, wiring, ease to use, and other advantages; can be adjusted through the infrared remote control speed adjustment, brightness adjustment, static color selection as well as a variety of dynamic lighting change effect. Operating temperature between -20-60 ℃, power supply voltage 5V, 12V, 24V optional, connection mode support common sun, common negative two, the maximum load current of 2A each way. the market price of 15 yuan.
The LED screen controller is very important, he mainly uses the receiver card to accept the sender card to transmit the video signal, and then the video signal in the data separation, and finally divided into the external cache. Eventually can realize the display mode is colorful, the display playback cycle, and the operation of the time is also very convenient, and flexible, stability is also very strong, and most importantly the room life is very long.
Contact OPCBA.COM to fabricate controller PCBA.