Five kinds of dimming LED lighting so that you fully understand

Article Source：   Published：2015/03/02

Now the problem is actually mostly LED lighting control systems and light electrical mismatch, which has become a common problem in the industry, while also diversified LED control system is also a higher challenge. Since the LED light-emitting principle with traditional lighting different, depending on the PN junction to emit light, LED light source with power, because of their different chips used, current and voltage parameters are different, so the internal wiring structure and the distribution of different circuits, resulting in the production light dimming driver vendor requirements are not the same. If the control system and lighting equipment is not complete, it may cause the lights go out or blinking, and possible damage to the LED driver circuit and a light source.
There are five ways to control LED lighting on the market:
A frontier cut phase (FPC), SCR dimming
2, tangential phase (RPC) MOS tube dimming
3,1-10VDC
4, DALI (Digital Addressable Lighting Interface)
5, DMX512 (or DMX)

1, the leading edge phase cut dimmer control
Frontier is using SCR dimming circuit, starting from the AC phase 0, the input voltage chopper until thyristor, the only input.
The principle is to adjust the alternating current in each half-wave of the conduction angle to change a sinusoidal waveform, thus changing the effective value of the alternating current, in order to achieve the purpose of dimming.
Leading edge dimmer adjustment with high precision, high efficiency, small size, light weight, easy remote manipulation, etc., dominant in the market, the majority of manufacturers of the products are of this type dimmers.
Leading edge phase control thyristor dimmers commonly used as a switching device, it is also known to use the advantages of SCR dimmers FPC dimmer LED lights on are: low light adjustment cost, compatibility with existing lines, without rewiring. FPC disadvantage is poor dimming performance, usually caused by narrowing dimming range, and would result in the minimum requirements for an individual or a small load of more than rated power LED lights.
Because half-controlled thyristor switch properties, only to open the current function, and can not be completely shutdown current, even to the lowest still weak current through micro-current and LED light-emitting properties, making use SCR dimming abound shutdown LED is still weak luminescence phenomenon, becoming this free wiring LED dimming promotion problems.
E-Linker EasyLink professional development of cutting-edge phase cut dimmer LED driver a good solution to this problem by "C-TURNOFF" technology to optimize the drive circuit to avoid "off constantly" and "bad strobe light" and other problems.
EasyLink E-Linker match before cutting phase dimming LED driver can be a perfect match for all types of lamps with other SCR dimming system for the user to save a wire and wiring work to solve the SCR dimming LED and non-matching Shutdown confusion pattern.

2, tangential phase control dimmer
After tangential phase control dimmer, using a field effect transistor (FET) or an insulated gate bipolar transistor (IGBT) device is made. After phase cut dimmer along general use MOSFET as a switching device, it is also known MOSFET dimmers, commonly known as "MOS tube."
MOSFET is fully controlled switch, both can be controlled open, you can also control off, so TRIAC dimmers can not completely turned off phenomenon does not exist.
Another MOSFET dimmer circuit is more suitable than the SCR dimming capacitive load, but because of the high cost and the dimming circuit is relatively complex, not easy to do stability characteristics, making the MOS transistor dimming not developed, SCR dimmer still occupy most of the dimming system market.
And cutting-edge phase cut dimmer compared to the trailing edge phase cut dimmer applications in LED lighting, because there is no minimum load requirement, which can achieve better performance on a single or very small lighting loads, however, Because rarely applied to MOS tube dimming system, generally made of a single knob lamp dimmer switch, after cutting such small power phase dimmers do not apply to the engineering field.
And many lighting manufacturers in the use of this dimmer for their dimming driver and dimming lamps do testing. Then his dimming products to engineering market had led after SCR dimming system with cutting phase modulation dimming driven projects often.
This dimming mode mismatch led to the dimmer flashes rapidly severe damage to the power or dimmer.

3,1-10V dimming
1-10V dimming apparatus has the two independent circuits, one for the normal voltage circuit, for turning on or off the power supply to the illumination device, the other is a low pressure circuit, which provides a reference voltage, telling lighting dimming level Before 0-10V dimming controller commonly used in fluorescent lamp dimming control for now, since the LED driver module plus a constant power supply, and a dedicated control line, 0-10V dimmer it can also support a large number of LED lights.
But the application is also very obvious shortcomings, the need for additional low voltage control signal to increase a group of lines, which greatly increased the requirements for construction.
      
4, DALI
DALI standard has defined a DALI network, including the largest 64 units (individually address), 16 groups and 16 scenes. Different illumination unit DALI bus can be flexibly grouped achieve different scene control and management.
In practice, a typical DALI controller 40 to control up to 50 lamps, can be divided into 16 groups, while some action can be processed in parallel. In a DALI network, capable of handling 30 to 40 per second control instruction. This means that the controller for each lighting group, the need to manage two per dimming command.
DALI is not really an ad hoc network, it is replaced by 1 ~ 10V voltage interface control ballast. Compared with the traditional 1-10V dimming, DALI advantage that each node includes a unique address code, and with feedback, as more distant do not appear like dimming 1-10V signal attenuation, but in practice this distance or engineering not more than 200 meters.
DALI is clearly not suitable for LED lighting control, a DALI network can only control 21 full-color LED lamps. DALI lighting control-oriented tradition, focusing on static control and system reliability, stability, compatibility.
The size of the LED lighting system is far greater than the DALI system, mainly the pursuit of artistic effect lighting performance, intelligent proper balance system, which requires the system needs to access a larger bus network, with unlimited scalability and high scenarios refresh capability.
Therefore, DALI lighting systems in large-scale projects tend to be incorporated as a subsystem other bus systems. E-Linker COS system can be easily linked perfectly compatible with DALI system. DALI dimming advantages not go into details, the disadvantage is still annoying signal line layout and high prices.
It is worth mentioning that the current DALI dimming driver in order to ensure that the microcontroller on standby at all times, when the lights are still required standby power consumption. EasyLink E-Linker with dimmers can physically power down when the lights to avoid energy losses during standby.

5, DMX512 dimmer
DMX512 protocol was first by USITT (United States Theater Technology Association) developed into a standard digital interface from the console to control the dimmer mode.
DMX512 beyond the analog system, but can not completely replace the analog system. DMX512 simplicity, reliability (if properly installed and used), and flexibility make it a choice of funds as permitted under an agreement.
In practice, DMX512 control mode, generally designed with the power supply and controller.
By DMX512 controller 8 to 24 lines, direct drive RBG LED lighting line, but in the building lighting project, due to weak direct current lines, demanding about 12 meters would be installed in a controller for parallel control bus Therefore, the controller traces very many, many occasions, can not even construction.
DMX512 receiver need to set the address, it can clearly receive dimming command, which in practical applications is very inconvenient. Interconnect multiple controllers to control complex lighting scheme, operating software design will be more complicated.
From this analysis we can see DMX512 lighting together more suitable occasions, such as stage lighting. The main drawback is that the sum DMX controller require special wiring layout and type, and requires some programming to set basic colors and scenes, which is a larger ongoing maintenance costs.