| On/Off Controller | Two-position switching based on a setpoint and switching differential | Low-voltage or mains-powered control circuits; application-dependent | Suitable for discrete loads such as heaters, pumps, fans, and relays | Setpoint control Load switching Status indication | Basic temperature control, water pumps, ventilation, refrigeration, and simple automation | Overcurrent protection, thermal protection, short-circuit protection, and relay contact ratings | Simple design, low cost, easy commissioning, and straightforward maintenance | Use a suitable switching differential and confirm that the controller can handle the load's starting current |
| PID Controller | Proportional-integral-derivative feedback control | Sensor-dependent; commonly accepts thermocouple, RTD, voltage, or current signals | Controls proportional heating, cooling, valves, drives, and other variable processes | Closed-loop control Auto-tuning Alarm management | Industrial ovens, process heating, packaging equipment, laboratory systems, and machinery | Sensor failure detection, high/low alarms, output limiting, and electrical isolation where specified | Accurate regulation, reduced overshoot, and improved process stability | Correct tuning depends on process response time, sensor placement, output type, and load characteristics |
| Solid-State Relay Controller | Electronic switching using semiconductor devices | Control input commonly uses low-voltage DC or AC signals | Commonly used for AC or DC loads within the device's rated voltage and current limits | Fast switching Silent operation Cycle control | Resistive heaters, lighting, motors with suitable switching arrangements, and automated production lines | Heat-sink requirements, transient suppression, overtemperature protection, and fuse coordination | No mechanical contact wear, low acoustic noise, and high switching frequency | Allow for heat dissipation, leakage current, inrush current, and failure modes that may leave the output energized |
| Phase-Angle Controller | Adjusts the conduction angle of an AC waveform | Usually designed for single-phase AC systems; exact limits depend on the circuit topology | Variable AC output for compatible resistive or motor loads | Voltage adjustment Power modulation Manual or analog control | Lighting dimming, heating control, universal motors, and selected ventilation equipment | Overcurrent protection, electromagnetic interference filtering, snubber networks, and thermal protection | Compact design and continuously adjustable AC power | Check load compatibility, harmonic distortion, minimum load, acoustic noise, and electromagnetic interference requirements |
| Variable-Frequency Drive Controller | Changes motor frequency and voltage using power electronic conversion | Available for many single-phase and three-phase supply configurations | Controls motor speed, torque, acceleration, and deceleration within rated limits | Speed control Soft start Energy optimization | Pumps, fans, conveyors, compressors, machine tools, and industrial motors | Overload, overvoltage, undervoltage, overtemperature, phase-loss, and ground-fault monitoring | Precise motor control, reduced starting current, and potential energy savings in variable-torque applications | Match motor voltage, rated current, duty cycle, enclosure, braking needs, and required control interface |
| Programmable Logic Controller | Programmed logic, sequencing, timers, counters, and feedback algorithms | Modular digital and analog input/output systems with application-specific signal ranges | Controls multiple devices and coordinated machine processes | Logic sequencing Data monitoring Communication | Manufacturing lines, water treatment, material handling, building systems, and process automation | Watchdog monitoring, diagnostic alarms, electrical isolation, program protection, and controlled shutdowns | Highly configurable, expandable, and suitable for complex automation tasks | Evaluate I/O count, scan time, communication protocols, programming support, cabinet space, and lifecycle requirements |
| Solar Charge Controller | PWM or maximum power point tracking for battery charging | Designed for specific photovoltaic array and battery voltage classes | Rated by charging current and compatible photovoltaic input power | Battery charging Load management System monitoring | Off-grid solar systems, telecommunications backup, lighting systems, and remote equipment | Overcharge, deep discharge, reverse polarity, short-circuit, overtemperature, and overvoltage protection | Improves battery charging control and helps protect storage components | Match battery chemistry, nominal voltage, maximum PV voltage, charging current, temperature compensation, and enclosure rating |
| Battery Management Controller | Monitors cell voltage, temperature, current, and state estimates | Designed for a defined number of series cells and battery chemistry | Controls charge and discharge paths through contactors, MOSFETs, or related switching devices | Cell balancing State estimation Event logging | Energy storage systems, electric vehicles, backup power, and portable battery packs | Overcharge, over-discharge, overcurrent, short-circuit, thermal, and cell-imbalance protection | Enhances battery safety, usable life, and system visibility | Confirm cell count, chemistry, balancing method, measurement accuracy, isolation requirements, and communication interface |
| Automatic Voltage Regulator | Adjusts or switches the power path to maintain a target output voltage | Input range varies by electrical system and regulator design | Rated in watts, volt-amperes, or output current | Voltage stabilization Surge response Output monitoring | Sensitive electronics, control cabinets, communication equipment, and small power systems | Overvoltage, undervoltage, overload, short-circuit, thermal, and surge protection | Helps reduce the effect of moderate supply fluctuations on connected equipment | Check input tolerance, output accuracy, response time, waveform quality, capacity, and bypass requirements |
| Power Factor Correction Controller | Controls switching stages to reduce reactive power and improve power factor | Used in AC power systems with a defined input voltage and frequency | Specified by input power, current, switching frequency, and correction target | Power factor control Harmonic reduction Current shaping | Industrial power supplies, data-center equipment, motor systems, and high-power electronic loads | Overcurrent, overvoltage, undervoltage, overtemperature, and switching fault protection | Improves supply utilization and can help meet applicable power-quality requirements | Assess load profile, harmonic limits, efficiency, thermal design, mains compatibility, and regulatory requirements |
| Smart Energy Controller | Digital measurement, rule-based control, optimization algorithms, and network communication | System-specific voltage, current, and communication interfaces | Controls multiple loads, storage units, renewable sources, or backup systems | Load scheduling Remote monitoring Demand management | Commercial buildings, microgrids, distributed energy systems, and integrated renewable installations | Communication loss handling, access control, abnormal-condition alarms, islanding-related functions where applicable, and safe shutdown logic | Supports coordinated energy use, data visibility, and flexible system operation | Verify interoperability, cybersecurity, local grid rules, data access, backup behavior, and communication standards |
