What is the role of ballast in lighting work?

The ballast of the lighting must not only ensure the normal work of the lighting, but also protect the lighting under abnormal conditions. The main protection functions of the ballast are: high temperature protection, over-voltage protection, protection during work, and start-up protection. Since the lighting electronic ballast is an electronic component, the service life of the capacitive component will be greatly reduced when the ballast is operated above 70 degrees for a long time. Therefore, a high-temperature protection circuit must be installed during operation to ensure the life of the ballast. And stability. Under abnormal conditions such as lightning strikes, the grid power supply voltage will produce a very short-term high-voltage surge. If there is no effective circuit to extract this instantaneous energy outside the circuit, it will cause permanent damage to the ballast. According to the surge level It is necessary to set up protection circuits of different strengths. In-work protection refers to the protection of abnormal conditions such as tube shell rupture, air leakage, and power surge after the lamp is normally lit. Under such abnormal conditions, if the protection circuit has a long response time or no protection, the ballast The start-up protection will be damaged in a very short time. It refers to the protection of the circuit when the lamp fails to ignite due to air leakage, low temperature, etc., and the circuit is in a capacitive or weakly inductive state. This protection is very critical. Most lighting The damage is caused by this phenomenon. In this case, multiple protection methods must be adopted for different situations. The abnormal protection of lighting is generally divided into two modes: non-locking and locking; in the non-locking mode, the switch tube is still in working state during the protection process, and the protection state is constantly activated. If the protection state takes a long time, it is easy to cause the power switch tube or the protection switch tube Damage. The switch tube of the lock mode does not work during the protection process, and the circuit supports the protection state for a certain period of time (the national standard requires more than 50 seconds), restart the power switch to work.