A PID (Proportional-Integral-Derivative) controller is a feedback control loop mechanism widely used in industrial control systems and other applications requiring continuous modulation and automatic adjustments. It automatically compares a desired target value (setpoint) with a system's actual value (process variable). The controller minimizes the error between these values by adjusting a control variable, utilizing proportional, integral, and derivative terms. The Proportional term responds to the current error, the Integral term addresses accumulated past errors, and the Derivative term predicts future errors. This combination allows for accurate and stable control of processes like temperature, flow, pressure, and speed.
PID controllers are manufactured by various companies, including Emerson Electric Co., ABB Ltd, Honeywell International Inc., Siemens AG, Yokogawa Electric Corporation, and Fuji Electric Co.. These controllers are found in a range of applications, such as maintaining consistent heat in ovens and furnaces, regulating pressure in pipelines, and managing the flow of liquids and gases. The price range for PID controllers varies depending on features and manufacturer, with some models available for under ₹1,500, while others cost above ₹7,001. Models like the Inkbird ITC-100 Series and ITC-106 Series are available for around $29.99. PID controllers are readily available through distributors like RS and online retailers like Walmart.