The four function groups of an SCR power controller are analyzed below:
1. Protection and Basic Control Functions
Electronic overcurrent protection: detects overcurrent via load-current CT measurement and cuts output to protect the thyristor elements.
Constant-voltage characteristic via voltage feedback: the voltage-control function provides stable output, achieving linear input/output voltage control through simple operation.
Soft-start function: sets a soft start appropriate to the load.
Additional functions (options).
2. Automatic Power-regulation Functions
Automatic power adjustment: continuously regulates the appropriate heating power from signals produced by a program controller, computer, or regulator — suitable for gentle control at low ranges.
Constant-current control (current feedback): suits pure-metal heaters and sintered MoSi2 heaters.
Constant-power control (power feedback): suits silicon-carbide and graphite heaters and high-stability control.
Power-linear control (voltage-squared feedback): regulates nickel-chromium heater loads using the linear power characteristic of input/output voltage.
3. Current-limiting Functions
Current limit: handles inrush at load startup and overcurrent in continuous use — for example pure-metal loads and tungsten/molybdenum heaters.
Startup output limit: reduces switch-on surge and protects the load at power-up.
Heater-break alarm: alarms and outputs when detecting heater breakage or power loss from heater faults.
Fast fuse: perfectly protects thyristor devices and power wiring during short-circuit or ground-fault overcurrent.
4. Power-adjustment Functions
Adapts to different manual devices — slope adjustment, base power (residual output), manual, and high/low settings.
