Control Design of the Micro-Flow Liquid Feeding System in the Drop Analyzer

摘要

In order to solve the problem of inconvenience for integration and operation complexity, the micro-flow fluid supply system based on STC12 series MCU is presented and implemented. STC12 has many advantages such as ultra-low power consumption, rich chip designs, high performance cost ratio, high speed, etc. The feeding system mainly consists of mechanical parts, a miniature stepper motor, a micro-stepping driver, MCU and its control circuit. The software program is written by PC to manage the feeding process of the start-stop, rotation direction, acceleration and deceleration of the motor. Both the flow rate and the flow flux can be controlled precisely and flexibly, so as to ensure that the test liquid is slowly delivered under quasi-equilibrium condition to shape into a satiated and uniform drop.