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Common dimming methods of LED lights

Time:2022-07-06 Views:981


With the rapid development of the LED era, the control of lamps is no longer simple to turn on and off. Various dimming methods have been used in various shopping malls, hotels, and office buildings to meet the needs of light environment at different times and scenes. .


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At present, the intelligent control dimming methods mainly include the following:


1. Frontier phase-cut control dimming


The principle is to adjust the conduction angle of each half-wave of the alternating current to change the sine waveform, thereby changing the effective value of the alternating current, so as to achieve the purpose of dimming. As a market-leading dimming method, cutting-edge dimming has the advantages of high accuracy, small size, light weight, and easy remote control. Most of the manufacturers' products are this type of dimmer. Leading edge phase control dimmers generally use thyristors as switching devices, so they are also called thyristor dimmers.


The advantages of thyristor dimmers are: low dimming cost, compatibility with existing circuits, and no need for rewiring to control the dimming along the phase cut. The disadvantage is that the thyristor has poor dimming performance, which usually results in a reduced dimming range and causes the minimum required load to exceed the rated power of a single or a small number of LED lighting. Because of the properties of the thyristor semi-controlled switch, it only has the function of turning on the current, but cannot completely turn off the current. Even if it is adjusted to the lowest level, there is still a weak current flowing through. After the LED is turned off, there is still a phenomenon of faint light emission.


2. Trailing edge phase-cut control dimming


The principle of the trailing edge tangential dimmer is to turn on immediately after the half-wave of the AC voltage starts, and turn off immediately when the half-wave voltage reaches the set conduction angle. The purpose of dimming is achieved by adjusting the conduction angle.


The trailing edge tangential dimmer generally uses a MOSFET as a switching device, which consists of a trailing edge phase controller, an active switch, a zero-crossing detection circuit and an overload protection circuit. It can not only dim incandescent lamps, but also adjust the electronic voltage load It also has good adaptability and works well in most cases.


Compared with the front phase-cut dimmer, the trailing edge tangential dimming does not require the minimum maintenance current and solves the problems of grid interference and noise. The theoretical matching is better, but the internal circuit structure is more complicated and the cost is controlled. Relatively high.


3. 0/1-10V dimming


0-10V dimming is also called 0-10V signal dimming, which is an analog dimming method. The difference from the thyristor dimming power supply is that there are two 0-10V interfaces (+10V and -10V) on the 0-10V power supply. It controls the output current of the power supply by changing the voltage of 0-10V to achieve adjustment. Light. It is brightest when it is 10V, and it is off when it is 0V. The 1-10V is only 1-10V for the dimmer. When the resistance dimmer is adjusted to a minimum of 1V, the output current is 10%. If the output current is 100% at 10V, the brightness will also be 100%. It is worth noting and the best distinction is that 1-10V does not have the function of a switch, and the lamps cannot be adjusted to the lowest off function, while 0-10V has the function of a switch.


Simply speaking, there are many lights in a room, and each light is equipped with a 0/1-10V control line and connected to the controller. As the controller adjusts, the voltage on the control wires changes and the lights are dimmed or brightened.


The disadvantage of 0/1-10V dimming is that multiple sets of lamps corresponding to one controller can only be changed at the same time. If you want to achieve different control for each lamp, you can only make the controller and lamps correspond one by one. When the number of lamps increases, it becomes very troublesome to operate.


4. DALI dimming


DALI (Digital Addressable Lighting Interface) is an international public standard lighting control communication protocol. The DALI system is suitable for scene control and light source fault status feedback. The DALI system endows lamps with new connotations. Each lamp has an independent address. The DALI system has no requirements for light sources and lamps, but requires ballasts, drivers and other components to comply with the DALI standard, and the addresses of lamps are reflected by them.


The four letters of DALI have their own meanings: Digital Digital Addressable Addressable Lighting Lighting Interface Interface. DALI can dim each luminaire equipped with DALI driver, and different lighting units on the DALI bus can be flexibly grouped to achieve different scene control and management. Compared with other dimming methods, the advantages of DALI dimming are: 1. Digital dimming, accurate, stable and smooth dimming; 2. DALI can communicate in both directions and can feedback the lighting conditions to the system; 3. DALI control is more flexible; 4. , DALI anti-interference ability.


Five, wireless control dimming


Wireless control dimming refers to adjusting the brightness, turning on and off of each group of lamps through WIFI, Bluetooth controller, etc., so as to change the light environment to form various lighting scenes. Compared with other dimming methods, it is more concise and convenient. Users can use mobile phones, Bluetooth panel switches, and smart speakers to adjust the light environment; the disadvantage is that the coverage is small and the number of lamps to be controlled is small, so it is more suitable for small houses such as home decoration and villas. Scope space usage.