WTO harmonization and HS codes

This articleList of contents:

• 1,WTO harmonization and HS codes Schematic diagram of water level automatic control device
• 2, Why doubleThe liquid level control system is more difficult to stabilize than the single liquid level control system
• 3, What is the controlled object in the controlled object water level automatic control system?
• 4. in the liquid level automatic control system, whether the control valve is the object of control or other

The schematic diagram of the water level automatic control device

can be realized, and the wiring can be done according to the diagram. It can be achieved with a 220V coil DC1-0910 contactor plus a solenoid valve, which can be achieved with a high and low liquid level switch.

. Base: Take two wooden boards of 30×15×0.8 cm3 as the upper and lower base plates, and the middle pillar is 30 cm high. Two. Water level: The left side of the lower bottom plate is the water level, A is the dangerous water level, which is connected by a straight-angled wire, the right end is fixed on the pillar, and the welding contact C is the dangerous water level contact.

Form a set of advanced liquid level display and control equipment with electric valves, which automatically opens and closes the electric valve. High and low water level control circuit diagram (II) Circuit diagram 1 shown in this paper is a simple and convenient scheme for controlling elevated swimming pools. The circuit is very simple and easy to manufacture.

The principle of water level controller: The water level controller generally measures the water level through the water level sensor, and then transmits the signal to the display controller. After that, the controller transmits the switching signal to the electric actuator, and finally the electric actuator switches the water pump.

The schematic diagram of the water level sensor of the drum-type fully automatic washing machine is as follows: the water surface rises, by measuring the air in the membrane chamber to compress the pipe, the air pressure in the membrane chamber rises, the film sheet moves, and the switch is pushed; there is a spring above the film sheet, and its tightness can be changed by eccentric wheels and levers (water level gear ).

Why is the dual-cape liquid level control system more difficult to stabilize than the single-cape liquid level control system

1. The integral effect is enhanced. The enhancement of the integral effect makes the system unstable and becomes a second-order system, and the output may oscillate, which makes the dual-capacitance liquid level control system more difficult to stabilize than the single-capacity liquid level control system. The proportion should be increased while the integral action is enhanced.

2. Because the double-capacitance is equivalent to the series of two single-capacitance, it becomes a second-order system, and the output may oscillate. The single-capacitance is a first-order system, and the output is exponentially monotonous.

3. Double-capacity sink is a common control object in the industrial production process. It is composed of two with self-balancing ability.The single-volume sink is connected in series, which usually requires fixed control of the lower sink level. The lower sink level in the double-volume sink is the controlled amount in this system, and the inlet flow of the upper sink is usually selected as the manipulation amount.

4. A stable system can quickly respond to fluctuations in the liquid level and maintain the stability of the liquid level. Control accuracy: The control accuracy of the single-capacitance liquid level system depends on the stability of the system, the performance of the controller and the accuracy of the liquid level sensor.

5. The impact of adjusting pid parameters on the single-capacity water tank is as follows: Proportional coefficient P: The larger the proportional coefficient, the greater the impact on the water tank temperature, and the response speed of the control system will also be accelerated, but the excessive proportional coefficient may cause system shock or instability.

6. Stability. RootAccording to Baidu Education Information, the performance indicators of the single-comer liquid level system include stability, control accuracy and response speed. Dual-capacity liquid level system is a common control system in industrial production, which is used to control the liquid level between two storage tanks.

What is the controlled object in the controlled object water level automatic control system?

The so-called controlled object refers to a controlled object or production process in a control system, also known as a controlled object or control object. In the automatic control system, it generally refers to the controlled equipment or process, such as the control of reactors and distillation equipment, or the control of heat transfer processes and combustion processes.

The accused object refers to the machine that needs to be controlled, and the control object is the control device.Subject: Machines, equipment or production processes that require automatic control. For example, the CNC machine tool automatically cuts the workpiece according to the predetermined program, where the CNC machine tool is the object of control.

In the water tank temperature control system, the controlled object is and the controlled quantity is.

in the liquid level automatic control system, whether the control valve is the accused object or other

1. The accused object refers to the machine that needs to be controlled, and the control object is the control device. Subject: Machines, equipment or production processes that require automatic control. For example, the CNC machine tool automatically cuts the workpiece according to the predetermined program, where the CNC machine tool is the object of control.

2. In the automatic control system, it generally refers to the controlled equipment or process as the object, such as the control of reactors and distillation equipment, or the control of heat transfer processes and combustion processes. From the perspective of quantitative analysis and design, the control object is only a part of the factor that affects the input and output parameters of the controlled equipment or the process, and is not the whole of the equipment.

3. The accused objectThe controlled object in the automatic control system generally refers to the control equipment or process (process, process, etc.), etc. In the automatic control system, the broad understanding of the controlled objects includes processing processes, motors, valves and other specific equipment; in a narrow sense, the understanding can be the input and output parameters of each equipment.

4. Solution: The control task of the system is to keep the height of the liquid level unchanged. The water tank is the controlled object, and the water tank level is the controlled variable. The potentiometer is used to set the expected liquid level height (usually the up and down displacement of the pointer is realized).