Working Principle
1. Burst Firing (Cycle Control / Zero-Crossing Trigger)
Triggered at the AC zero-crossing point. It turns on and off in complete sine wave cycles, adjusting the average power by changing the duty cycle (how many cycles on, how many cycles off).The output keeps complete sine waves without waveform distortion.
2. Phase Angle Control
Trigger with a delay within each half-cycle by changing the SCR conduction angle. It cuts part of the sine wave to realize stepless voltage and power regulation.The output waveform is cut and distorted, not a standard sine wave.
Comparison Table
表格
| Comparison Item | Burst Firing Cycle Control | Phase Angle Control |
|---|---|---|
| Trigger Mode | Zero-crossing, full cycle on/off | Phase delay, adjustable conduction angle |
| Output Waveform | Complete sine wave, no distortion | Waveform cut and severely distorted |
| Harmonic & EMI | Very low harmonic, low interference | High harmonic pollution, easy to interfere with instruments |
| Regulation Performance | Step adjustment, granular output | Smooth continuous stepless regulation |
| Response Speed | Slow, adjusted by AC cycles | Fast, millisecond dynamic response |
| Grid Impact | Grid-friendly, no pollution | Serious grid pollution, easy to damage compensation capacitors |
| Suitable Load | Resistive load, large thermal inertia heating equipment | Resistive / inductive load, transformer, lamp, graphite heating |
| Lamp & Filament | No flicker, long service life | Easy stroboscopic, shorten filament life |
| PID Matching | Stable constant temperature, less overshoot | Fast temperature compensation, high precision dynamic control |
Advantages & Disadvantages
Burst Firing - Advantages
Complete sine wave output, ultra-low harmonic, no interference to PLC, transmitters and instruments.
Zero-crossing switching without inrush current, prolong service life of heating elements and lamps.
Friendly to power grid, suitable for workshops with precision instruments and capacitor compensation cabinets.
Stable temperature operation with small fluctuation for long-term working.
Burst Firing - Disadvantages
Power adjustment is step-type, lower fine tuning accuracy.
Slow response, not suitable for applications requiring fast temperature rise / fall.
Not applicable to motors, transformers and inductive loads, easy to cause low-frequency jitter.
Phase Angle Control - Advantages
Smooth continuous voltage regulation with high linearity and precision.
Fast response, small temperature deviation, suitable for high-precision temperature control.
Supports inductive loads, transformers, infrared lamps and graphite heating.
Ideal for small thermal inertia equipment that needs rapid dynamic power adjustment.
Phase Angle Control - Disadvantages
Waveform distortion produces massive high-order harmonics, polluting the power grid.
Strong EMI interference, affecting nearby temperature controllers, sensors and communication modules.
Large inrush current, causing lamp stroboscopic and accelerated aging.
Easily burn reactive power compensation capacitors in distribution cabinets.
Application Recommendations
Choose Burst Firing Priority
Ovens, tunnel furnaces, mold temperature machines, electric heating tubes and other large inertia resistive loads.
On-site equipped with PLC, transmitters and precision instruments that are sensitive to interference.
Power distribution system with reactive power compensation capacitors.
Infrared / halogen heating lamps requiring no flicker and long lifespan.
Choose Phase Angle Control Priority
Graphite heating, silicon carbide rods, primary side voltage regulation of transformers.
Inductive loads, motor speed regulation, induction heating equipment.
Processes requiring fast temperature response and ultra-small temperature difference.
Small thermal inertia heating occasions needing rapid PID power follow-up.
Summary
Burst Firing: Anti-interference, grid-friendly, best for large inertia electric heating and occasions with capacitor compensation.
Phase Angle Control: High precision, fast response, suitable for transformers, inductive loads and high dynamic precision temperature control.