The use of LED explosion-proof lamps is very large, so […]
The use of LED explosion-proof lamps is very large, so there are certain protective measures in the process of use. What are the specific protective measures?
The principle of LED explosion-proof lamps is the same as that of explosion-proof lamps, except that the lamp beads are LED lamp beads. This is to prevent the ignition of surrounding explosive mixtures such as explosive dust environments, explosive gas environments, and gas. a specific luminaire.
In actual work, the LED has a current upper limit of 20 mA, but generally, the current will increase due to various reasons during use. If correct protection measures are not taken, the increased current will exceed a certain value. It will break down after the time and magnitude. For the protection of LEDs, we first need to use a fuse, but the fuse is one-off, and the response speed is also very slow, so the effect is poor and it is also very troublesome in the process of use, so the fuse is not suitable. Used in finished products such as LEDs.
We can generally choose to automatically restore the fuse PTC, and then through experiments, the more reliable way to use it is to make the lamp beads that are heated by the PTC force farther away. In the actual circuit, we can choose the following two ways:
1. Shunt protection: General LEDs are divided into many series branches. For example, for a voltage of 24 volts, seven LED light beads can be used in series and then a resistor is added. The current is generally seventeen. To 19 mA, according to the need, you can choose an integer multiple of seven light beads to combine into a whole lamp. Add a PTC element in front of each branch for protection respectively. The advantage of this method is the reliability of protection. Better and more accurate.
2. Overall protection: A PTC component is connected in front of all lamp beads to protect the entire lamp. This method is relatively simple and does not take up space. This method is more satisfactory for household products.