Industrial-Automation
There are three controls that need to be adjusted for a proportional flow controller to function correctly. This process requires practice, and the experience gained can lead to stable control of the flow or velocity of a fluid. The actual flow rate of the fluid is measured by the flow sensor, which must be positioned in the fluid circuit to prevent disturbances that may cause oscillations around the setpoint. The flow rate zone, where the output ranges from 4.1 mA to 19.9 mA, drives the AC motor from 0% to 100%, representing the proportional band. For example, a 50% proportional band of a 200 lph setpoint corresponds to 100 lph. The motor operates at 100% drive until reaching 150 lph and turns off above 250 lph, with the proportional band existing between these two flow rates. As the flow rate approaches 250 lph, the motor gradually reduces power until it completely shuts off. When the setpoint equals the process variable, the output is 12 mA, indicating the motor runs at 50% of its total power. The motor and drive combination must provide a flow rate corresponding to the control signal of 12 mA, ensuring stability during regular operation. The maximum flow rate needed by the system should be achievable at 80% of the motor's power to accommodate load and line variations. The flow circuit should maintain normal flow resistance to minimize oscillations. A 4-20 mA input/output analog multiplexer with a cascade option is included in this design, which allows multiple transmitters to feed into a single 4-20 mA output. This simple circuit was designed for budget-friendly automation systems and employs a digital byte or word for multiplexing. As the process is slow, this is a slow scanner, enabling many analog inputs to be multiplexed into one analog input for a digital-to-analog converter. In near real-time systems, a faster multiplexer could be employed or multiplexing could be entirely avoided. The circuit has been produced in several units, and the PCB design is available. This is a photo of a 3-wire mains-powered RTD temperature transmitter that outputs a 4-20 mA signal. The circuits and PCB designs for the RTD PT100 transmitter and multiplexer can be found in Solderman's Basic Electronics. With the advent of new technologies such as Zigbee and Modbus, transmitters can be classified based on the measured parameters, including temperature, flow, or events, which should reach an intelligent data storage and analysis system. This system may involve a human operator recording data manually or an embedded controller, or it could be a computer network or web application. Pressure is another crucial parameter after temperature. In hydraulic and pneumatic systems, measuring, indicating, controlling, and logging pressure is essential. Popular pressure sensors utilize either piezoresistive or strain-gauge technologies, with strain-gauge types available in metal foil or semiconductor film. Simple systems may use analog strip chart recorders for reporting, while data loggers and PC-based data acquisition systems enhance this capability by making data electronically accessible for analysis and reporting through database applications. The liquid level in containers with uniform cross-sections can be calculated by measuring the appropriate parameters. The RTD Pt-100 transmitter converts thermocouple mV or RTD mV signals into a 4-20 mA current output. The part numbers on the circuit and silk screen may differ, but the PCB remains functional. The output serves as a current source rather than a current sink and connects to a 4-20 mA multiplexer with a common ground. This low-cost transmitter was developed to transmit RTD information over long distances, with the 4-20 mA output interfacing with an analog multiplexer connected to a GE-Fanuc PLC system and a 486 computer. The analog multiplexer is constructed around specific components. Additionally, circuits and boards for a mini temperature transmitter designed for a platinum 100-ohm temperature sensor are available.
The proportional flow controller operates based on a feedback mechanism that adjusts the motor's power output according to the flow rate detected by the flow sensor. The system is designed to maintain a stable fluid flow by continuously measuring the actual flow rate and comparing it to the desired setpoint. The flow sensor's placement is critical; it must be strategically located to minimize disturbances such as turbulence or pressure drops that could lead to oscillations.
The proportional band is a key parameter in this control system, defining the range of flow rates where the motor will adjust its output. For instance, if the system is set to maintain a flow rate of 200 liters per hour (lph), the proportional band of 50% would mean that the motor operates at full power until the flow rate reaches 150 lph and gradually reduces its power until it completely turns off at 250 lph. This gradual adjustment helps prevent sudden changes in flow, contributing to system stability.
The integration of a 4-20 mA analog multiplexer allows for the collection of data from multiple sensors or transmitters, enabling a centralized control mechanism. This is particularly beneficial in complex systems where various parameters need to be monitored and controlled simultaneously. The use of digital multiplexing facilitates the management of these inputs efficiently, ensuring that the control system can respond to changes in real-time.
Furthermore, the incorporation of modern communication technologies such as Zigbee and Modbus enhances the system's capability to interface with advanced data storage and analysis solutions. This allows for improved monitoring, control, and reporting of critical parameters like temperature and pressure, which are essential for effective system operation. The design also considers the need for compatibility with existing PLC systems and data acquisition setups, ensuring a seamless integration into industrial environments.
Overall, this circuit design exemplifies a robust approach to fluid control, emphasizing stability, efficiency, and adaptability to various operational requirements.There are three Controls to be Adjusted to make a Proportional Flow Controller Perform Properly. This method has to be practiced and experience gained from it can be used to get very good and stable Control of the Flow or Velocity of a Fluid. This is the Actual Flow Rate of the fluid in the flow sensor or its path. It is very important that the Fl ow Sensor is placed at a position in the fluid circuit in such a way to avoid cushions which may lead to oscillations around the Setpoint. The Flow rate zone in which the Output is 4. 1mA to 19. 9mA which in turn Drives the AC-Drive >> Motor from 0% to 100% is the proportional Band. It is Given in % e. g. 50% PB of 200 lph SP is 100 lph. Band 150 lph 250 lph eg : The Motor is at 100% Drive on` till 150 lph and off` above 250 lph. ` Between 150 to 250 is the PB. A little above 150 the Motor reduces power gradually till at 250 it turns off. When SP=PV the output is 12mA (ideal) here the motor runs at 50% of the total power. The Motor / Drive Combination must at 12mA Control signal give a flow Rate at which the system is used for most of the time this gives good stability.
The max flow rate setting required by system must be achievable at 80% of Motor Time Axis Power this is to make allowance for load and line regulations. The Flow Circuit should have normal resistance to flow to reduce Oscillations. Here is a 4-20 mA In/Out Analog Mux with Cascade option. This is a simple circuit i designed to make a Automation System within a budget. This takes 4-20mA from many Transmitters and gives out just one 4-20 mA output. The Mux is done with a digital byte or word. This is a slow scanner as process is slow, that way many analog inputs can be multiplexed and sent into one analog input of a D/A.
In near real time systems a faster mux could be used or mux totally avoided. This was made in some numbers, so the pcb Read More This is the Photo of a RTD 3-W Mains Powered Temperature 4-20mA Transmitter. The Circuits and PCB are here RTD PT100 Transmitter and Multiplexer. From Soldermans Basic Electronics Now with new Technologies like Zigbee and Modbus, We can classify Transmitters as shown below.
The Measured Parameter Temperature, Flow or Events Has to reach an Intelligent Data Storage and Analysis System. It may just be an Human Operator who jots the data on a Notepad and Turns a Few Dials based on his Experience or an embedded controller.
It could even be a Computer Network or a Web Application used by Read More Pressure is the next most important parameter after Temperature. In Hydraulics and Pneumatics, the measurement, indication, control and logging-charting of pressure is indispensable.
Popular Pressure Sensors are based on either Piezoresistive or Strain-Gauge Technologies. Strain-Gauge types can be Metal Foil or Semiconductor Film. The Analog Strip Chart Recorder is used in Simple Systems where a Record or Report has to be generated. Data Loggers and PC based Data Acquisition Systems expand this capability by making the Data Electronically Accessible for Charting-Analysis and Reporting using database applications.
The Liquid-Fluid Level in containers of uniform cross-section can be computed by measuring the Read More This is a RTD Pt-100 Transmitter, It can Convert Thermocouple mV or RTD mV to 4-20 mA Current Transmitter. The part numbers on Circuit and silk screen may not match. But the PCB may be usable. The output is a current source and not a current sink. It goes to a 4-20mA Mux with a common ground. The Circuit RTD-Pt-100-Transmitter Circuit. This low-cost transmitter was made to send RTD information in a 4-20mA over long distance. The 4-20mA was the input to a Analog-Mux which interfaced to a GE-Fanuc PLC system and a 486 Computer.
The Analog Multiplexer Built around Read More These are the circuits and boards of a Mini Temperature Transmitter for a Platinum hundred ohms temperature Sensor. RTD-3W-Transmitter Circuit. 🔗 External reference
The proportional flow controller operates based on a feedback mechanism that adjusts the motor's power output according to the flow rate detected by the flow sensor. The system is designed to maintain a stable fluid flow by continuously measuring the actual flow rate and comparing it to the desired setpoint. The flow sensor's placement is critical; it must be strategically located to minimize disturbances such as turbulence or pressure drops that could lead to oscillations.
The proportional band is a key parameter in this control system, defining the range of flow rates where the motor will adjust its output. For instance, if the system is set to maintain a flow rate of 200 liters per hour (lph), the proportional band of 50% would mean that the motor operates at full power until the flow rate reaches 150 lph and gradually reduces its power until it completely turns off at 250 lph. This gradual adjustment helps prevent sudden changes in flow, contributing to system stability.
The integration of a 4-20 mA analog multiplexer allows for the collection of data from multiple sensors or transmitters, enabling a centralized control mechanism. This is particularly beneficial in complex systems where various parameters need to be monitored and controlled simultaneously. The use of digital multiplexing facilitates the management of these inputs efficiently, ensuring that the control system can respond to changes in real-time.
Furthermore, the incorporation of modern communication technologies such as Zigbee and Modbus enhances the system's capability to interface with advanced data storage and analysis solutions. This allows for improved monitoring, control, and reporting of critical parameters like temperature and pressure, which are essential for effective system operation. The design also considers the need for compatibility with existing PLC systems and data acquisition setups, ensuring a seamless integration into industrial environments.
Overall, this circuit design exemplifies a robust approach to fluid control, emphasizing stability, efficiency, and adaptability to various operational requirements.There are three Controls to be Adjusted to make a Proportional Flow Controller Perform Properly. This method has to be practiced and experience gained from it can be used to get very good and stable Control of the Flow or Velocity of a Fluid. This is the Actual Flow Rate of the fluid in the flow sensor or its path. It is very important that the Fl ow Sensor is placed at a position in the fluid circuit in such a way to avoid cushions which may lead to oscillations around the Setpoint. The Flow rate zone in which the Output is 4. 1mA to 19. 9mA which in turn Drives the AC-Drive >> Motor from 0% to 100% is the proportional Band. It is Given in % e. g. 50% PB of 200 lph SP is 100 lph. Band 150 lph 250 lph eg : The Motor is at 100% Drive on` till 150 lph and off` above 250 lph. ` Between 150 to 250 is the PB. A little above 150 the Motor reduces power gradually till at 250 it turns off. When SP=PV the output is 12mA (ideal) here the motor runs at 50% of the total power. The Motor / Drive Combination must at 12mA Control signal give a flow Rate at which the system is used for most of the time this gives good stability.
The max flow rate setting required by system must be achievable at 80% of Motor Time Axis Power this is to make allowance for load and line regulations. The Flow Circuit should have normal resistance to flow to reduce Oscillations. Here is a 4-20 mA In/Out Analog Mux with Cascade option. This is a simple circuit i designed to make a Automation System within a budget. This takes 4-20mA from many Transmitters and gives out just one 4-20 mA output. The Mux is done with a digital byte or word. This is a slow scanner as process is slow, that way many analog inputs can be multiplexed and sent into one analog input of a D/A.
In near real time systems a faster mux could be used or mux totally avoided. This was made in some numbers, so the pcb Read More This is the Photo of a RTD 3-W Mains Powered Temperature 4-20mA Transmitter. The Circuits and PCB are here RTD PT100 Transmitter and Multiplexer. From Soldermans Basic Electronics Now with new Technologies like Zigbee and Modbus, We can classify Transmitters as shown below.
The Measured Parameter Temperature, Flow or Events Has to reach an Intelligent Data Storage and Analysis System. It may just be an Human Operator who jots the data on a Notepad and Turns a Few Dials based on his Experience or an embedded controller.
It could even be a Computer Network or a Web Application used by Read More Pressure is the next most important parameter after Temperature. In Hydraulics and Pneumatics, the measurement, indication, control and logging-charting of pressure is indispensable.
Popular Pressure Sensors are based on either Piezoresistive or Strain-Gauge Technologies. Strain-Gauge types can be Metal Foil or Semiconductor Film. The Analog Strip Chart Recorder is used in Simple Systems where a Record or Report has to be generated. Data Loggers and PC based Data Acquisition Systems expand this capability by making the Data Electronically Accessible for Charting-Analysis and Reporting using database applications.
The Liquid-Fluid Level in containers of uniform cross-section can be computed by measuring the Read More This is a RTD Pt-100 Transmitter, It can Convert Thermocouple mV or RTD mV to 4-20 mA Current Transmitter. The part numbers on Circuit and silk screen may not match. But the PCB may be usable. The output is a current source and not a current sink. It goes to a 4-20mA Mux with a common ground. The Circuit RTD-Pt-100-Transmitter Circuit. This low-cost transmitter was made to send RTD information in a 4-20mA over long distance. The 4-20mA was the input to a Analog-Mux which interfaced to a GE-Fanuc PLC system and a 486 Computer.
The Analog Multiplexer Built around Read More These are the circuits and boards of a Mini Temperature Transmitter for a Platinum hundred ohms temperature Sensor. RTD-3W-Transmitter Circuit. 🔗 External reference