Comparison of five dimming modes of LED strip in current industry

Our company has been engaged in the LED lighting industry for more than ten years, mainly producing LED high pole lamps, LED street lamps, LED flat lamps and other LED lamps. With the development of technology, dimming methods have been very rich. Today, let's learn about the five common control methods of LED lighting equipment in the market:

1. Leading edge phase cutting, thyristor dimming
2. Dimming of rear edge tangent MOS transistor
3. 0 / 1-10V dimming
4. Dali (digital addressable lighting interface)
5. DMX512 (or DMX512) dimming

1、 Dimming principle
1. The thyristor circuit is used to control the dimming of the front edge tangent phase. Starting from the AC phase 0, the input voltage is chopped until the thyristor is on. Its principle is to adjust the conduction angle of each half wave of alternating current to change the sinusoidal waveform, so as to change the effective value of AC current, so as to realize the purpose of dimming.

2. Dimming with back edge tangent control
It is made of field effect transistor or insulated gate bipolar transistor equipment. The back edge tangent dimmer generally uses MOSFET as switching device, so it is also called MOSFET dimmer, commonly known as "MOS transistor". MOSFET is a fully controlled switch, which can be controlled on and off, so there is no phenomenon that the thyristor dimmer can not be turned off completely.

3. 0 / 1-10V dimming
There are two independent circuits in the 0 / 1-10V dimmer. One is a common voltage circuit, which is used to turn on or turn off the power supply of the lighting equipment. The other is a low-voltage circuit. It provides a reference voltage and feeds back the dimming level signal of the lighting equipment. The constant power source is added to the LED driver module, and there is a special control circuit. Therefore, the 0 / 1-10V dimmer can also support a large number of LED lighting Light.

4. Dali dimming
Dali standard has defined a Dali network, including up to 64 units (independent address), 16 groups and 16 scenarios.
Different lighting units on Dali bus can be grouped flexibly to control and manage different scenes.
5. DMX512 dimming
DMX512 is a digital dimming protocol, which divides the light level from 0 to 100% into 256 levels. The control system can realize 256 gray levels of R, G and B. Its output signal transmission mode is: RS485 differential signal transmission, which effectively ensures the reliability of its signal.

2、 Comparison of several dimming methods
1. Dimming front
Advantages: high regulation precision, small size, light weight, easy remote control and other advantages, occupying a leading position in the market.
Disadvantages: the front cut dimmer is easy to produce large noise. It is not recommended to use this dimming method in high demand occasions.
2. Back edge dimming
Advantage: no load requirements, resulting in better performance on a single lighting unit or on very small loads. Disadvantages: high cost, relatively complex dimming circuit, not easy to do stable.
3. 0 / 1-10V dimming
Advantages: simple application, good compatibility, high precision, good dimming effect.
Disadvantages: additional control lines and controllers are required.
4. Dali dimming
Advantages: accurate and smooth dimming, more flexible single lamp control, two-way communication, strong anti-interference ability, fault feedback.
Disadvantages: additional control lines and controllers are required.
5. DMX512 dimming
Advantages: powerful control function brings rich lighting effects to building lighting, night scene lighting, studio and variety stage.
Disadvantages: special wiring layout and type are required, and certain programming is required to set basic colors and scenes, which is costly for later maintenance.

4、 Frequently asked questions
1. Load problem of thyristor dimmer?
The load of LED dimmer varies with LED dimmer and light source. Derating should be considered to adapt to spikes caused by drivers. Typical
The derating percentage of the dimmer shall be 25% - 30% of the rated load of the dimmer.
2. The actual transmission distance of 0-10V signal?
And the signal line path, material, power signal current, power quantity are related. For example, 1.5mm 2 copper wire is connected to the oches dimming power supply,
The transmission distance is 500m, and the voltage drop is less than 0.1V.
3. Dali debugging site can not find the lamp address?
Check whether the signal line is in good condition, and ensure that the number of system power supply does not exceed 64, and the bus power supply capacity is insufficient.
4. If the 0-10V power supply signal line is reversed, will it be damaged?
No, the power will be on or off for a long time.