The basic working principle of the projector is that through the relevant control of the host control board, they will irradiate the light on the display element of the image, so as to produce the image, and then project it through the lens. Projectors require a lot of power to convert electrical signals into optical signals. Generally, the working current is 6-7A. After the high-voltage rectifier reduces the working voltage, the working voltage is about 30V. The high-power tube in the projector will heat and rise with the duration of the current. Some parts of the machine are easy to be short circuited or damaged for a long time. The fault current in the circuit will increase exponentially, up to tens of amps. If there is no overcurrent protection, the machine will be seriously burned down, which will lead to fire and irreparable losses.
In the design of projector overcurrent protection, some engineers use disposable fuses, which is still prone to problems. If the disposable fuse is too large to fuse beyond the rated value, it cannot play a role of insurance and is unsafe. If it is too small, it will fuse before reaching the rated value, affecting the normal power consumption.
During design, designers can use PPTC self-healing fuse for overcurrent protection. It is made of high polymer and nano conductive particles through special processing. If a fault occurs, the current in the circuit will increase exponentially. Through the self-healing fuse, PPTC will generate heat, quickly turn into high resistance, and disconnect the conductive link path to achieve the purpose of protection. As long as the fault is eliminated, it will power up again and you can continue to work.
