What is a PID Controller?
A PID (Proportional Integral Derivative) controller is a device that makes changes to a system based on current and intended settings. PID controllers are used in a wide variety of industrial control systems and are the most commonly used feedback controllers in the world. PID controllers allow users to obtain and/or maintain preferred conditions within a system by modifying a variable input until preferred conditions are reached.
How a PID Controller Works
PID controllers rely on three main elements: the process variable, the setpoint, and the manipulated variable. The process variable refers to the system’s current condition. For example, in a hot water system, the process variable would be how hot the water currently is. The setpoint refers to the system’s intended conditions. For example, the setpoint is how hot or cold a user wishes the water to be. The manipulated variable refers to the actual mechanism that allows the system to change its conditions. For example, the manipulated variable is the valve that allows the hot water system to adjust how much hot water is allowed to flow into the tap. When a user adjusts the temperature of the water, the system compares what the current water temperature is and the intended water temperature that the user sets and calculates the difference between the two. The system then moves the valve accordingly to increase or decrease the hot water level in the tap.
Applications
PID controllers are used in a variety of devices and equipment, most of which are automated and do not require any complex processes. They are used in water purification systems along with other sensors in order to alter the level of solvents and other chemicals in the water as well as control mechanisms that transport the water from one area of the facility to another. PID controllers are also used in signal modulation for digital devices to measure varying voltages.
Disadvantages
Although PID controllers are the most widely used control mechanism in the world, they are also the most basic. Therefore, PID controllers are significantly limited in their capabilities, especially when complex processes are required to perform a task. PID controllers are only capable of measuring varying inputs and calculating the difference between them. Because of this, some subject specific industries must use larger and/or more expensive controllers.
|
|
- Magnetic Water Treatment
It is common for those who receive hard water all over the world to attempt to find a plausible technique or treatment system to soften the water. Magnetic water treatment is a way to eliminate or reduce the water’s hardness. This technique is also referred to as Anti-scale Magnetic Treatment” (AMT). Those who magnetically treat [...]...
- What Causes Evaporation?
When the Earth begins to get too hot, the water increases in temperature. As the water continues to get hotter, it begins to undergo a phase change in which water turns to gas. The water droplets turn into water vapor because the temperature has caused the individual water molecules to speed up considerably. This process [...]...
- What is a Variac?
Variac is the trademark name of a variable autotransformer. A variable autotransformer is a single-coil transformer in which two portions of the same coil are used as the primary and the secondary. Variable autotransformers are used for the same purposes as regular transformers, but handle lower voltages. They also differ from regular autotransformers in that [...]...
- What Causes Typhoons?
A typhoon is nothing more than a hurricane that occurs in the North West Pacific Ocean. The same conditions that cause a hurricane in the Atlantic ocean that hit the United States every summer are the ones that cause a typhoon. However, a typhoon does have a series of specific “rules” to exist and therefore, [...]...
- How Water Cooling Works
Water cooling is one of the newer cooling systems available for computers with high-end cards and chips. This cooling system rests on the principle that water is a much better conductor of heat because of its high thermal conductivity and high specific heat. Water cooling systems for computers works much like the cooling system in [...]...