How to choose LED switching power supply

2019-12-25 18:12:31

 

Answer: first of all, see your LED lamp, output voltage is how many volts, the total power is how big. If these two are confirmed, you can basically confirm the LED power supply. For example, the output of the LED lamp is 12V voltage and the power is 10W. Then you can buy the switching power supply of 12V1A(also 12W).

1. What are the switching power supply and ordinary power supply used in LED lights

 

Generally speaking,LED drive is also a kind of switching power supply, but it has a few special points, which are also the common of this kind of switching power supply, so it is always classified as LED drive. 6 V, 12 V.. , but generally not more than 25.6 V, because after more than this number, when open the LED will momentarily due to a bad to burn the conduction of the leds may. While the voltage is not constant, but varies with the load change, in order to achieve the purpose of constant current. 2, the output current is constant, the ideal circuit is no matter what LED the characteristic curve of change, drive power supply current remains the same. But limited to precision components, or there will be a small amount of change, and this change is also an important parameter to determine whether a driver circuit excellent, LED power supply

 

Answer: there are two possibilities. One is that there is a quality problem with your switching power supply. The second kind is your lamp belt power is too big switch power supply can not take, you can go to see your lamp belt power is how much, because should use how much power switch power supply.

Well, for the led light belt, if you buy, you can look at the picture and buy again, mainly to see whether the workmanship is fine, is not a small workshop. If you don't know how to choose,

 

 

Generally speaking, it refers to: in the process of electrification, the current changes from large to small, the voltage obtained by the LED lamp current sampling circuit, to control the LED light on and off, when the current is very small will turn off the LED light, of course, this can also indicate the current is large when the light off, according to the specific situation!

 

Constant voltage power supply, constant current power supply. Do more generally constant current, wide applicable scope. LED is a kind of is not sensitive to voltage, but the degree of current sensitive device, general list of the white hair white leds allow current is 15 to 50 ma, current value as durable, service life is the longest, but the brightness is minimal. Instead, the bigger the light current, also the shortest service life

 

 

 

 

The reason is that the input end of the switching power supply has a large filter capacitor, and the relay coil is under light load. After the switch is turned off, the power stored in the capacitor can supply the switching power for a long time, so there will be a delay. The solution is to directly control the relay coil and string the control switch directly into the coil circuit.

 

Switching power supply at the moment of disconnection induced by LED discharge, is a normal phenomenon. Normally switching power supply is designed with this factor in mind, in parallel in the load loop

 

 

Using power switch with potentiometer to adjust LED light brightness is technically feasible: just change the current limiting resistance of LED drive circuit to potentiometer. Problems to be faced in practice :

1. The power switch potentiometer is placed on the power cord, and the high and low voltage are mixed together. It is not so easy to install lamps and lanterns through various countries.

 

2. The low quality of the potentiometer is prone to produce carbon film conductivity, resulting in flickering of lights or intermittent phenomena during adjustment. The potentiometer quality is good, the unit price is high; For lighting, the cost burden is too heavy.

 

3. An LED is of low power and limited brightness, so it can only be used as a small night light; There seems to be no need for dimming. With a large power rate, you can use the principle of the packet dimming, the cost is very low, not easy to fault.

 

One LED connected to 220V voltage? Is that a little crazy? So the potentiometer and the LED are easy to hang. Let's do it in PWM