EN 简体中文 English


LED driver knowledge: protection function
2021-06-15 17:14:47
The protection function of LED driving power supply is fault protection, which usually includes over voltage protection, over current protection, over temperature protection and short circuit protection. Fault protection refers to the protection action that occurs when the relevant circuit functions of the power supply are activated due to the change of internal and external conditions such as input power supply, load, environment, cooling circuit or device failure, which threatens the safety of the power supply and causes the power supply to fail to work normally.
OVP: Over Voltage Protection. A characteristic of a switching power supply circuit that protects the switching power supply and the load from abnormally high voltages at the output.
OCP: Over Current Protection. In the DC switching power supply circuit, in order to protect the adjustment tube in the circuit short circuit, the current increase will not be burned. Its basic method is, when the output current exceeds a certain value, adjust the tube in the reverse bias state, so as to cut off, automatically cut off the circuit current.
Short Circuit Protection: To limit the output current of the switching power supply to a safe value in case of a Short Circuit to protect the switching power supply from damage.
OTP: Over Temperature Protection Circuit. The high integration and light weight and small volume of the switching regulator in the DC switching power supply greatly improve the power density in the unit volume. Therefore, if the internal components of the power supply device do not have corresponding requirements for its working environment temperature, it is bound to make the circuit performance deteriorate and the components fail prematurely. So in the high power DC switching power supply should be set up overheat protection circuit.
There are the following protection methods:
1. Restart (disconnect the power and connect it again, and the power returns to normal. Automatic and manual two);
2. Hiccup (intermittent output);
3.Fold-back speed (a method that can linearly reduce the output current to normal when the load approaches a short circuit)
4.Constant current limit The output current is not increased indefinitely due to load overload or short circuit. Even if the load appears short circuit condition will not cause equipment shutdown and power damage).
5. Overcurrent/Overload/Overvoltage/Overtemperature Fault, usually refers to the dangerous state when the output current/power/(or input) voltage and radiator temperature exceed the protection threshold above the rated value of the power supply.
An good quality LED drive power has built-in protection circuit to ensure the safe use of power, improve the reliability of power, and extend the service life of power.