Working principle of needle detector
The magnet in the upper and lower magnetic heads and the needle detection coil are combined with the power supply of the machine to form a needle detection magnetic field. When foreign materials such as iron filings with iron properties enter the needle detection area, it will cause changes in the local magnetic field environment. Causes local current instantaneous magnetic field fluctuations. The detected abnormal current will be transmitted to the control circuit board and compared with the previously set needle detection sensitivity; when this changed current value reaches or exceeds the needle detection sensitivity value set by the device during use, The control circuit board will give the machine a series of instructions such as alarm, stop, and belt rewind; and finally complete these actions.
Needle detector maintenance
The conveyor belt should be cleaned thoroughly every time, and a special cleaning cloth should be used. The surface of the conveyor belt must be cleaned because the product is relatively dirty. The back of the conveyor belt should also be cleaned consciously. During daily use, dirt containing trace amounts of iron may adhere. If such dirt is accumulated, even if there is no needle in the machine, it will react to the dirt on the conveyor belt.