Collection:Proportional Controllers

Proportional controllers are used in applications where it is necessary to maintain a process variable, such as temperature, pressure, flow rate, or level, within a specific range or at a constant setpoint. An electrical signal, such as a Pulse Width Modulation (PWM) signal, often controls them. The controller transmits a signal to the proportional solenoid valve, directing it to change its state in response to changes in the process variable under observation. Consequently, the valve adjusts the flow of the medium (liquid or gas) to attain the intended flow profile.

A proportional solenoid valve helps control the fluid flow rate accurately with a very fast response, rather than just completely closing or opening the valve. Utilizing a controller designed for proportional solenoid valves gives you greater control, less hysteresis, and the ability for a closed-loop feedback system (depending on controller inputs) compared to other control methods.

Proportional controller advantages

• They can manage various valves, including those for processes and motors.
• Certain models (like Burkert) can save settings for valves and flow meters.
• The controller can be easily connected to proportional solenoid valves using a plug-in (DIN) or screw-on connection.
• Provide multiple control functions, such as:
  • Continuous control for smooth adjustments.
  • 2-point control for basic settings.
  • 3-point control for more options.
  • On/off control for simple operation.

Applications

1. Temperature control systems, such as HVAC (Heating, Ventilation, and Air Conditioning), where maintaining a consistent temperature is crucial for comfort or process requirements.
2. Pressure control in fluid systems, like water supply networks or industrial process lines, where maintaining constant pressure is essential for system performance and safety.
3. Flow control in chemical processing, where the precise mixing of reactants depends on accurate flow rates to ensure product quality and process efficiency.
4. Level control in tanks and reservoirs, where the level of liquids must be kept within certain limits to prevent overflows or to ensure adequate supply for downstream processes.
5. Speed control in automated machinery requires precise regulation of motor speeds for consistent operations and product quality in manufacturing processes.
6. Gas dosing in medical or laboratory equipment, where exact amounts of gasses must be administered or mixed for patient care, experiments, or production of specialized chemical compounds.

Selection criteria

• Material construction: Choose controllers made from polyamide (PA) and polycarbonate with 20% glass fiber for enhanced strength and longevity, ensuring they perform reliably in different industrial settings.
• Electrical connection: Look for options such as DIN-A connectors and screw terminals to suit various installation needs and provide easy electrical connectivity.
• Input sensor compatibility: For flexible system integration, ensure the controller supports a broad spectrum of input sensors, including binary, flow rate, 0-10V/4-20mA signals, temperature, ratio, and dual frequency.
• Controller outputs: Select a controller with diverse output options like binary, single PWM, 0-10V/4-20mA, and dual PTM to meet various actuation requirements and ensure system compatibility.
• IP protection rating: Opt for controllers with appropriate IP protection to defend against dust and water, which is vital for operation in demanding industrial environments.
• Valve compatibility: Confirm that the controller matches the specific proportional valve.
• Input signal type: Identify the input signal needed from the sensor, such as temperature or flow, to match the controller's capabilities.
• Setpoint accuracy: Choose a controller that can accurately maintain the setpoint, the target value the system aims to sustain.
• Control range and resolution: Consider the necessary control range and resolution to ensure precise process regulation.
• Power consumption: The controller's electrical efficiency can impact the system's overall energy consumption, especially in continuous operation.
• Operating environment: Account for the operating conditions, including temperature and humidity, to select a controller that can withstand the specific environment.
• Electrical specifications: Verify that the controller meets the electrical requirements, such as voltage and current, for your application.
• PWM frequency: The PWM frequency is critical for properly operating the proportional valves. If the frequency is not set correctly, the valves may not function as intended, leading to suboptimal performance or even failure of the system they are a part of.

When to choose a proportional valve controller

If your application demands the ability to fine-tune and dynamically adjust the flow or pressure, you should consider a proportional valve controller rather than just switch it on or off. A standard valve with a basic or no controller would suffice for simpler operations that only require full or no flow.