What is a thyristor regulator?
A thyristor regulator is a semiconductor switch that receives signals from controllers or PLCs and control the power supplied to a heater. It is used in heating equipment such as electric furnaces to stably control the temperature.
Compared to mechanical switches, it features high-speed power control, a longer lifespan due to the absence of contact, and quieter operation.
For more information on how thyristors control power, how they differ from SSRs, and control methods, please see "What is a Thyristor Regulator?".
Choosing a Thyristor Regulator
The thyristor regulator is selected based on the type of heater, operating temperature, and required control method. In particular, selecting feedback method that matches the heater's resistance temperature characteristic is crucial.
1. Choose based on the heater material and operating temperature.
The temperature characteristic of a heater's resistance vary depending on the material it is made of. Check the material of the heater you will be using and its operating temperature, and select feedback method that is appropriate for those conditions.
2. Select from control methods.
Phase control Method
Power can be continuously control, and feedback methods such as voltage, current, and power can be selected according to the heater characteristic. On the other hand, since the output waveform contains harmonic constituent, the impact on the power supply must be considered.
| Heater Material |
Iron Chromium, Nickel Chromium |
Silicon carbide |
Platinum, tantalum, molybdenum, tungsten |
| Normal temperature |
600～1000℃ |
1200～1600℃ |
1500～1800℃ |
| FB method |
・Voltage FB type
・No FB type |
・Power FB type |
・ Current FB type |
*Please select the FB method according to characteristic of load (heater).
Frequency division control method
This method control power using zero-cross switching. Compared to phase control methods, it is features by the absence of harmonics in the output waveform. On the other hand, because the output is on/off, flicker and temporary drops in power supply voltage may occur.
Frequency division control methods have limitations regarding heater type and power supply configuration. The heater material is limited to nichrome, and it cannot be used for primary side control of transformers.
| Heater Type |
Iron Chromium, Nickel Chromium |
|
| Normal temperature |
600～1000℃ |
| Frequency division method |
Time proportional control, three-phase
Time-division control (ΔΣ signal modulation method), single phase |
3. Confirm feedback method.
With thyristor regulators, it is necessary to select an appropriate feedback method depending on resistance temperature characteristic of the heater. The supported methods vary depending on the model, including voltage feedback, current feedback, power feedback, and no feedback.
For more information on feedback process, please see About FB.
