What Is a Controller?
A controller is a component of a machine or system. It is a generic term for a device that decodes commands, sends signals to other devices, and controls their operation.
Types of Controllers
A control panel is a set of devices used to control a machine or system using electrical signals. It consists of human-operated parts such as switches and buttons, parts that turn power on and off such as breakers, relays, and timers, inverters and servo amplifiers that are control units, and sequencers (PLC) and microcontrollers (8-bit and 32-bit microcontrollers) that give commands. The control panel circuitry can be divided into two main categories: control circuits and power circuits.
The control circuit receives input signals from the operation panel or switches and operates the control unit, such as an inverter, according to the signals. On the other hand, the power circuit sends electric signals to the power unit through the inverter to activate it. There are various types of power units that receive signals, and the name of the control unit differs according to the type.
For example, there are motor controllers, sensor controllers, safety controllers, motion controllers, robot controllers, thermo controllers, LCD controllers, and more that control the operation of all types of motors.
Inverter power modulation methods include PWM, PFM, and PAM, with the PWM method being widely used.
Servo Mechanisms
One of the control devices indispensable in industrial fields such as factory automation is a servo mechanism that automatically controls the position, orientation, and posture of an object according to commands.
The servo controller operates the motor through the servo amplifier, while the encoder attached to the motor sends feedback signals to the servo amplifier. High-precision control is achieved by controlling the motor so that there is no error between the feedback signal and the command issued by the controller.