LED circuit is one of our most common circuits. LED is also the product that is closest to our life. LED circuits usually use a large number of resistors to ensure the normal operation of LED circuits, but for many people, they also encounter such problems. It is very easy to be burned, especially in the thyristor LED circuit, the resistor is very easy to burn if not designed properly.

In real life, many situations require circuit design engineers to connect thyristor circuits to LED bulbs. Although it can be operated in a short time, after a period of use, a short circuit of the capacitor occurs, and in severe cases, the resistor is burnt. After the light control thyristor circuit is connected to the LED bulb, the resistance is burned as shown below: 


The circuit is shown in Figure 1. The C1 short circuit is due to insufficient voltage or loss of the device, which is independent of the LED load. The thyristor phase modulation dimmer can not carry LED lights, nor can it carry any fluorescent lamps, only incandescent lamps, but with incandescent lamps, there is no need to connect RC loops on the thyristor. The RC loop is in inductive load. Suppress excessive voltage change rate and prevent thyristor from being turned on. Normally, RC is responsible for dV/dt suppression. If you want to suppress the spike current, you must string the inductor. In Figure 1, it is 400V, which is obviously not in compliance with safety regulations.

 From the figure, it is not difficult to see that this is not the ideal design of the LED circuit for the circuit engineer. In many cases, the engineer should design the circuit in response to the customer's requirements. In this case, the most innocent is the resistor. This is not the damage caused by the resistance quality problem, but the problem that the circuit design is unreasonable. This situation is rare, and most of the time engineers can circumvent this unreasonable circuit design.