Thyristor CCR VS IGBT CCR
Two power-electronic approaches to regulating the constant current supplied to airfield series lighting circuits. Thyristor CCRs regulate output mainly through phase-angle control using thyristor/SCR devices, while IGBT CCRs use high-frequency electronic switching for regulation. Both deliver the same fundamental function — a regulated constant current to the series lighting circuit — using different power-electronic technology.
At a Glance
| Feature | Thyristor CCR | IGBT CCR |
|---|---|---|
| Main switching device | Thyristor / SCR | IGBT |
| Control principle | Phase-angle control | High-frequency PWM / switching control |
| Output regulation | Constant current | Constant current |
| Dynamic response | Generally slower | Generally faster |
| Output waveform | More dependent on phase control | More precisely controlled |
| Harmonics / power quality | Typically higher | Typically better |
| Efficiency | Good | Generally higher |
| Power factor | Typically lower / less controllable | Typically better |
| Control flexibility | Moderate | High |
| Electronics complexity | Lower / older technology | Higher / modern technology |
| Typical advantage | Robust, proven, simpler | Precision, efficiency, fast response |
What Is a Thyristor CCR & an IGBT CCR?
Thyristor CCR
A Thyristor CCR regulates the constant-current output mainly by phase-angle control using thyristor/SCR devices. It controls the amount of AC power delivered to the series lighting circuit by controlling the firing angle of the thyristors, and is a mature, proven regulation technology.
Main functions
- Convert AC input into a regulated constant current
- Adjust firing angle to control effective power
- Provide multiple intensity steps for the lighting circuit
- Supply airfield series lighting circuits
IGBT CCR
An IGBT CCR uses Insulated Gate Bipolar Transistors as fast electronic switching devices to regulate the constant-current output. High-frequency switching under electronic control allows more precise regulation than conventional phase-control devices.
Main functions
- Convert AC input into a regulated constant current
- Use high-frequency switching for electronic control
- Provide precise, fast-responding intensity control
- Supply airfield series lighting circuits
Phase-Angle Control vs High-Speed Switching
Both regulators exist to do the same job — deliver a constant, regulated current to the series lighting circuit. The difference is entirely in how each one gets there.
THYRISTOR CCR IGBT CCR
| |
v v
PHASE-ANGLE CONTROL HIGH-SPEED SWITCHING
| |
v v
CONTROL AC POWER ELECTRONIC CONTROL
| |
v v
CONSTANT CURRENT CONSTANT CURRENT
Easy memory: Thyristor → controls by firing angle. IGBT → controls by fast switching.
Engineering point: The difference between the two CCR types lies in the power-electronic technology used for regulation — not in the fundamental lighting function they deliver.
How Each Technology Regulates Current
Thyristor CCR
The thyristors/SCRs are switched at controlled points within the AC waveform. Changing the firing angle changes the effective power delivered to the load, and therefore the regulated circuit current.
AC WAVEFORM
/"\ /"\
/ \ / \
__/ \__/ \__
^
firing angle
IGBT CCR
The IGBTs switch at high frequency under electronic control, well beyond the speed of conventional phase-control devices, which allows more precise regulation of the output current.
AC INPUT | v POWER ELECTRONICS (IGBTs) | v HIGH-FREQUENCY CONTROL | v CONSTANT-CURRENT OUTPUT
Dynamic Response Comparison
One of the important advantages of IGBT technology is its fast switching and control capability, which can make IGBT-based CCRs more responsive to changes in the required output.
| Stage | Thyristor CCR | IGBT CCR |
|---|---|---|
| Command received | Command | Command |
| Control mechanism | Phase control | Fast electronic switching |
| Result | Current response | Current response (generally quicker) |
Power Quality Considerations
Both technologies ultimately perform the same job — supplying controlled current to the series lighting circuit — but their waveform characteristics differ.
Efficiency
A phase-controlled thyristor waveform can introduce additional reactive/harmonic effects. Modern IGBT designs, with power electronics and filtering, can provide improved efficiency and power quality, though the exact figures depend on the specific CCR design.
Harmonics & power quality
A phase-controlled thyristor system can produce a more distorted input/output waveform. An appropriately designed IGBT system can provide more sophisticated waveform control. The exact harmonic performance depends on the particular CCR design, filtering and control architecture.
Power factor
| Technology | Power Factor Characteristics |
|---|---|
| Thyristor | More dependent on firing angle and load |
| IGBT | Can achieve improved / controlled power factor |
Improved power factor and power quality are among the important advantages associated with modern power-electronic CCR designs.
Achieving Lighting Intensity Steps
Both CCR types can provide multiple lighting intensity levels (low, medium, high) for the series lighting circuit. The difference is in how each regulator achieves those levels.
Thyristor CCR
Change firing angle → change effective power → change current
IGBT CCR
Change switching control → change power transfer → change current
Same Job, Different Technology
Regardless of the regulation technology, the pilot does not see a different lighting function merely because the CCR uses thyristors or IGBTs — the technology sits behind the lighting system.
CCR (Thyristor or IGBT)
|
v
CONTROLLED CURRENT
|
v
SERIES LIGHTING CIRCUIT
Engineering Parameters
| Parameter | Thyristor CCR | IGBT CCR |
|---|---|---|
| Semiconductor | SCR / Thyristor | IGBT |
| Switching speed | Lower | Much higher |
| Primary control | Phase angle | High-frequency switching |
| Current regulation | Good | Very precise |
| Dynamic response | Moderate | Fast |
| Efficiency | Good | Generally higher |
| Harmonics | Higher potential | Lower potential with suitable design |
| Power factor | Typically less favourable | Can be actively improved |
| Control flexibility | Moderate | High |
| Electronics | Simpler | More sophisticated |
| Technology maturity | Mature | Modern |
| Airfield lighting function | Same | Same |
What Each Technology Asks of Maintenance
Thyristor CCR
Advantages
- Mature technology
- Relatively straightforward power stage
- Robust semiconductor devices
Potential considerations
- More conventional / older architecture
- Larger passive components may be required
- Harmonic and power-factor characteristics need attention
IGBT CCR
Advantages
- Precise electronic control
- High switching speed
- Potentially better efficiency and power quality
Potential considerations
- More sophisticated electronics
- Greater dependence on control electronics
- Thermal management and electronic diagnostics are important
Myths vs Facts
Both technologies deliver the same constant-current output to the series lighting circuit — the pilot sees the same lighting function regardless of the regulation technology used.
Thyristor CCRs remain a mature, robust and widely used technology. Technology selection depends on the applicable project requirements, not on age alone.
IGBT designs generally offer higher efficiency and better power quality potential, but the actual figures depend on the specific CCR design, filtering and control architecture.
Choosing Between Thyristor and IGBT CCR
When selecting a CCR technology, consider:
- Applicable ICAO/national CCR requirements
- Required dynamic response of the lighting circuit
- Power quality and harmonic requirements
- Power factor requirements
- Available electrical infrastructure
- Airport-specific technical specifications
- Life-cycle and maintenance capability
- Cost and procurement considerations
- Spares and technical-support availability
Which Technology Applies Where?
Thyristor CCR and IGBT CCR are two power-electronic technologies for regulating constant current to airfield series lighting circuits. Their key distinction is the switching device and control principle used for regulation — phase-angle control versus high-frequency electronic switching.
The final selection should always be based on the current applicable standard, project specification, required dynamic response and power-quality requirements — not on a generic comparison alone.
Engineering & Expert Notes
Check Output Waveform and Harmonics
Power QualityVerify behaviour against the specification.
Check Cooling
ThermalVerify ventilation.
Check Interface and Monitoring Compatibility
IntegrationConfirm with the control system.
Plan Spares and Training for Your Type
SupportMake sure staff and parts are ready.
Frequently Asked Questions
The power-electronic technology used for regulation — phase-angle control using thyristors/SCRs versus high-frequency switching using IGBTs.
Yes. Both are Constant Current Regulators supplying controlled current to series lighting circuits; the regulation technology is behind the lighting system, not part of the visual function itself.
Generally, yes — high-speed IGBT switching typically allows a faster dynamic response than phase-angle control, though exact performance depends on the specific CCR design.
IGBT CCRs generally offer better potential for harmonics and power-factor control, but actual performance depends on the specific design, filtering and control architecture.
No. It is a mature and proven technology that remains in wide use. Selection depends on project requirements rather than technology age alone.
Yes. Both can provide low, medium and high intensity levels — a Thyristor CCR does this by changing the firing angle, while an IGBT CCR changes its switching control.
Governing Documents
For an actual airport project, verify the current applicable editions of the relevant standards and equipment specifications before using this comparison for project design.
ICAO Annex 14, Volume I
Aerodrome Design and Operations — general requirements for aeronautical ground lighting systems and current regulators.
FAA AC 150/5345-10
Specification for Constant Current Regulators and Regulator Monitors — the governing FAA spec for the L-828/L-829 CCRs, regardless of whether the internal design uses thyristor or IGBT switching.
ICAO Aerodrome Design Manual
Applicable material covering AGL electrical design, series circuits and constant current regulator considerations.
National CAA / DGCA / AAI Requirements
For Indian airport projects, also verify applicable DGCA requirements, AAI requirements, airport-specific technical specifications, project drawings and contract specifications.
Final Engineering Note
Exact CCR performance figures, harmonic behaviour and power-factor characteristics vary by manufacturer and design. For final selection, use the manufacturer's technical data and the applicable current standard rather than a generic comparison page.
Thyristor CCR and IGBT CCR are two power-electronic technologies for supplying constant current to airfield series lighting circuits. Their key distinction is the regulation principle — phase-angle control versus high-frequency electronic switching.
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