Hardware circuit of closed-loop control device for

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The hardware circuit of the water gate closed-loop control device

the closed-loop control card adopts the high-performance STC89C52 single chip microcomputer provided by STC company, and the periphery is supplemented by the circuit of receiving and sending signals. The main structure is shown in Figure 2

stc89c52 single chip microcomputer produced by STC company integrates 8031 and flash memory technology. It comes with 8K. Most of them need heat treatment to strengthen the alloy, eliminate the internal stress of castings, stabilize the structure and part size. B internal program memory has long service life, data is not easy to volatilize, and has logic encryption, so that the developed system is not easy to be copied, but also has low price, strong confidentiality and low power consumption, The application is flexible and convenient. The control signal received by the microcontroller system (lower computer) can be the signal set manually through the human-computer interaction interface of the lower computer, or the signal transmitted by the upper computer through RS232 serial communication, and the set value of the gate opening can be displayed on the LCD display. At the same time, the actual value of the gate opening collected by the lower computer is displayed on the LCD display in real time and sent to the upper computer PC. In this way, the set value of the gate opening and the actual value of the gate opening fed back are displayed on the LCD. The control of the gate by the lower

bit machine is based on the closed-loop control principle, comparing the actual opening value with the set opening value, controlling the anti reverse direction of the motor according to the comparison results, and then driving the multi turn potentiometer and driving the change of the gate opening to achieve the expected gate control effect. The system hardware circuit is shown in Figure 3

function and design of each component of the hardware circuit

1) single chip microcomputer operation processing and monitoring

● compare the command signal with the current gate opening sampling value, and control how the motor operates

● scan the keyboard, stroke ignition and other peripheral components at any time, and disconnect the commands sent by the upper computer at any time to execute some emergency processing instructions

2) TLC2543, a 12bit serial A/D converter chip of Texas Instruments (TI), is selected in the forward channel

system. 78l05 is used to generate stable voltage, which is not only convenient to adjust, but also the tension wheel should be re tensioned; The score is stable. The gate opening signal is a multi turn potential. In terms of structure, we are also very clear that the 0 ~ 5 V voltage analog signal collected by the controller becomes a digital signal that can be received by the single chip microcomputer system through the A/D converter, and is sent to the designated register for the next work instruction. In addition, the forward channel also processes the zero potentiometer signal. Hardware electromechanical - hardware improves mechanical properties and reduces the gas permeability of polymers; As a marketing service for metal oxide Electromechanical industry

3) the backward channel

controls the rotation direction of the motor through the motor driver, and controls the buzzer to send an alarm signal in case of abnormal conditions

4) man machine channel

● send the percentage value of the actual gate opening to LCD for display

● the microprocessor scans and identifies the working process, and reflects the current working state through the indicator light

● the working state of the system can be set by pressing the key

5) mutual channel

the transmission of control instructions or data between the single chip microcomputer application system and the microcomputer, and the signal transmission should follow certain communication procedures and coding requirements

the principle of single chip microcomputer controlling the motor is as follows:

● port P0.4 controls the motor stall direction, and port p0.5 is connected to the motor stall operation indicator

● port p0.3 controls the motor reverse direction, and port p0.6 is connected to the motor reverse operation indicator

6,) audible and visual alarm circuit

p3.4 u is connected to the audible and visual alarm. When the opening of sluice gates [, J reaches the maximum and minimum limits, the audible and visual alarm will work. At this time, the system will send an audible and visual alarm signal, and the operator should be notified immediately to check the condition

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