The In short, LED driver is also a kind of power transformer. It has only a few unique aspects and is also related to this power transformer. Therefore, it is habitually classified as LED driver These aspects are unique: The
The 1. its voltage output is a multiple of 3.2, that is to say, the voltage output forms are 3.2V, 6.4v, 9.6V, 12.8v... But generally not more than 25.6v at most, because after this number, when the LED is turned on, due to the poor one-dimensional property of the product, there will be the possibility that the last turned on LED will be burned out in an instant. This voltage is not constant, but varies with the load. [led switching power supply ] The
The 2. Its output current is stable. The idealized power supply circuit is that the current of LED driver will not change no matter how the characteristic curve of LED changes However, only limited to the precision of components, there will still be a small amount of changes, and this change is also a key parameter to distinguish whether the optocoupler circuit is excellent or not. The on-off of LED and the culvert number of working voltage are "three segments" of a discrete system, so maintaining a constant current power supply is very important The
The 3. its start is soft start. Because the consistency of LED is very poor, and the activity of internal PN junction changes instantaneously when it is turned on, the drive of LED is usually designed as soft start to avoid this defect. The
The 4. its circuit requirements are the simplest. In many cases, the circuit is required to be installed in a small space to match the convenience of LED lighting, so the circuit should be as simple as possible, which can save costs and reduce energy consumption. The
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The 5. Generally, it does not require protection. Since many commodities have the same structure as general lighting fixtures, the safety level can be similar to that of lighting fixtures. However, this article 5 is an "optional reading item", so there is no need to misunderstand when you master it. Because some drivers must be protected, this feature is only applicable to the current popular power circuit, not necessarily to the future power circuit development trend The
The To sum up, soft start, constant current, step voltage and simple circuit are its characteristics [led switching power supply ] The
The Here's another point to emphasize: it pays attention to the constant current power supply from the human side, but it doesn't mention the working voltage. It's not right, because the definition of the constant current power supply is irrelevant to the working voltage. For example, if a switching power supply is only a 30V output constant current power supply, if you lead the way,. The working voltage of is 30V. At this time, if you connect the LED, the components working with the PN junction immediately will burn before the most accurate reflection of the power circuit. Because all power circuits must have a reaction speed, and the work in the power circuit. The device is a semiconductor. All PN junctions can react only after the power supply gives a sampling signal. However, the PN junction of the led directly starts to work, so its "reaction" is faster than the "multiple PN junction coordination" in the circuit, and it burns in advance!. However, this drive is also used in special occasions, but this led drive does not allow an open circuit at the output end. To be exact, it is "LED is not allowed to be connected after the output end is open circuit". Therefore, the concept of voltage must be added at the same time of constant current, which is more conducive to understand the conduction function curve of LED. The
The In fact, LED driven switching power supply is also a kind of power transformer, because it has many characteristics of power transformer; The difference is that the LED driven switching power supply is generally output by a constant current power supply, while the traditional power transformer is generally a constant current source, which is often referred to as the power switch adjustable regulated power supply; LED driven switching power supply can be considered as a special power transformer [ LED switching power supply ] The
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