For membrane switch panel converters or membrane panel power supplies, their performance and working reliability may be damaged or affected due to input voltage fluctuations, external load failures, and their own abnormalities. At the same time, the reason for their damage may be due to the abnormal operation of membrane panel converter, which causes damage to the load or load equipment. Therefore, to make membrane panel converter system and load work safely and reliably, it must have a complete protection function. As a result, researchers have proposed various types of protection schemes and protection circuits for different protection needs.
The membrane panel device is the core component of the membrane panel converter with a relatively high price. Therefore, protective measures must first ensure the safe and reliable operation of the membrane panel device. In addition, the load of membrane panel converter or the membrane panel power supply generally contains a large number of highly integrated devices, which generally have poor resistance to electricity, heat and impact. Therefore, in order to protect the membrane panel converter, its own safety and the load should be considered.
At present, there are many types of protection. In addition to the aforementioned over-current protection, over-voltage protection, under-voltage protection, and over-heat protection, there are also polarity protection, program protection, and over power consumption protection. Since there are many types of membrane panel converters or membrane panel power supplies with different usage, the requirements for protection also have different emphasis, which should be determined according to specific requirements.
After the protection circuit is added to the switching converter or the membrane panel power supply, it is necessary to increase the components, which in turn will affect the reliability of the system. Therefore, the reliability of the protection circuit itself must be high to improve the reliability of the entire system, thereby increasing the mean time between failures (MTBF) of the membrane panel converter itself. This requires strict protection logic, simple circuits and minimal components.
In addition, the maintenance degree of the failure of the protected circuit itself must be considered to ensure the normal operation and high reliability of the power supply.