The weighing Feeder is the feeding equipment for the micro-range precise weighing Electronic scale. It is a precise feeding screw feeder, mainly composed of several major components such as the power unit, buffer bin, stirring device, screw main shaft and quick shut-off gate. The controller section mainly consists of important components such as the electrical current detection and transmission device of the screw feeder, the feed door switch detection device, the sound and light alarm, the PLC, the touch screen, the frequency converter and the stepper motor driver. The self-developed precise feeding screw feeder is adopted as the feeding equipment, which consists of a shallow long trough feeding wheel and a quantitatively adjustable feeding door. The screw feeder is equipped with a buffer bin by itself, and the buffer bin is provided with stirring blades, which can effectively prevent the material from clumping and arching. The screw conveyor blades adopt a variable pitch design to control the material conveying height to gradually become thinner from thick. The feeding wheel is driven by a variable frequency motor, and the feeding amount can be fine-tuned by changing its rotational speed. The feed door is driven by a stepping motor. By adjusting its opening degree, the feeding amount can be roughly regulated to ensure that the material is evenly, stably and accurately fed into the weighing carrier.

The measurement and control of the weighing feeder are integrated. The weighing module signal and the speed signal are directly sent in, and the output control signal (including start, stop and feeding quantity instructions) is directly sent to the frequency converter. The local electrical control cabinet contains a frequency conversion drive motor speed controller, thereby regulating the motor speed of the feeder. Transformers, relays and other components used in the speed control system, etc. The control methods are all realized locally through the controller. That is, the signal of the weighing module is first sent to the Feeding machine controller or weighing instrument. The controller calculates the feeding quantity and then sends it to the Weighing system through a 4-20mA signal. The feeding quantity is automatically adjusted by the current of the screw feeder. The detection device detects the working current of the screw feeder in real time and transmits the signal to the weighing system. By comparing with the set current, adjust the opening degree of the feed door and the rotational speed of the variable frequency motor. The feeding quantity instructions and start-stop signals output by the weighing system must first be sent to the controller, which then outputs frequency instructions to the frequency converter to control the rotational speed of the feeder. Ultimately, the purpose of adjusting the feeding amount is achieved.