DMFC36 Three-Phase Thyristor Driver Module (110–230V Supply, 230V Mains)

The DMFC36 Driver Module is a versatile, microprocessor-based three-phase thyristor controller designed to provide precise and reliable power regulation for industrial applications. It is engineered to drive three-phase SCR (Silicon Controlled Rectifier) assemblies, particularly for resistive heating loads, offering selectable phase-angle, burst-fire and rapid burst-fire control.

With advanced control functions, automatic phase-rotation detection and adjustable soft-start, the DMFC36 provides flexible power management while helping to minimise mains flicker and harmonic distortion. Its microprocessor-based design supports a wide range of analogue control signals, making it suitable for integration into industrial heating systems, power supplies and specialist automation equipment.

The DMFC36 can operate in phase-angle mode before automatically switching to burst-fire control when the input signal reaches a preset level. It also features isolated pulse transformer outputs, onboard status indication and standard DIN rail mounting for straightforward installation.

Key Features

• Dual Control Modes: Selectable phase-angle and burst-fire operation.
• Rapid Burst-Fire Control: Single-cycle and dual-cycle firing with an adjustable time base.
• Adjustable Soft Start: Ramp control from 0–30 seconds for smooth power application.
• Wide Control Signal Compatibility: Accepts 0–5V, 0–10V, 1–5V, 2–10V, 0–20mA and 4–20mA signals.
• Manual Control Option: Compatible with a manual potentiometer input.
• Automatic Phase-Rotation Detection: Detects phase alignment to support correct three-phase operation.
• Reduced Mains Flicker: Rapid burst-fire control helps minimise supply fluctuations, particularly with generator supplies and high-impedance power networks.
• Reduced Harmonic Distortion: Rapid burst-fire operation can reduce harmonic distortion compared with phase-angle control.
• Isolated Pulse Transformer Outputs: Provides electrical isolation between control and thyristor trigger circuits.
• Onboard LED Indicators: Displays power status, burst rate and fault conditions.
• Integrated Fuse Protection: Internal 1A fuse.
• DIN Rail Mounting: Designed for convenient installation within industrial control panels.

Technical Specifications

• Product: DMFC36 Three-Phase Thyristor Driver Module
• Controller Type: Microprocessor-based
• Supply Voltage: 420/460V AC (selectable via LINK J1)
• Other Voltages: Available on request
• Supply Frequency: 50/60Hz
• Auxiliary Supply: 24V AC/DC @ 500mA minimum
• Power Consumption: 7VA
• Control Inputs: 0–5V, 0–10V, 1–5V, 2–10V DC, 0–20mA, 4–20mA or potentiometer
• Control Modes: Phase Angle, Standard Burst Fire and Rapid Burst Fire
• Burst-Fire Time Base: 1–30 seconds (standard)
• Rapid Burst-Fire: Single-cycle or dual-cycle
• Soft Start: Adjustable 0–30 seconds
• Trigger Output: 25kHz pulse transformer output
• Initial Trigger Current: 500mA
• Sustaining Trigger Current: 250mA
• Output Isolation: 3.5kV
• Internal Fuse: 1A, 32mm
• Status Indicators: Green power LED, red fault LED and yellow burst-rate LED
• Protection Rating: IP20
• Operating Temperature: 0°C to +65°C
• Mounting: DIN rail
• Weight: Approximately 500g

Operation

Three-Phase Thyristor Power Control

The DMFC36 controls the firing of three-phase thyristor assemblies to regulate the electrical power delivered to a load. By adjusting the firing method, the module can provide precise power regulation for industrial heating and other three-phase applications.

It supports three main operating options:

• Phase-Angle Control: Adjusts the thyristor firing angle during each AC cycle to provide continuously variable power control.
• Standard Burst-Fire Control: Switches groups of complete AC cycles according to a proportional time base, providing controlled power delivery.
• Rapid Burst-Fire Control: Uses single-cycle or dual-cycle switching to provide faster power modulation and reduce fluctuations in the electrical supply.

Automatic Phase-Angle to Burst-Fire Switching

The DMFC36 can initially operate in phase-angle mode during start-up. When the control signal reaches a preset level, the module automatically changes to burst-fire operation.

Once the controller has switched to burst-fire mode, it remains in that mode even if the control signal subsequently falls below the switching point. Phase-angle operation resumes when the unit is switched off or reset.

Reduced Flicker and Harmonic Distortion

Rapid burst-fire control is particularly useful where the electrical supply has a high impedance, such as installations with long power cables or systems powered by generator sets.

Conventional phase-angle control can contribute to mains voltage disturbances and harmonic distortion. The DMFC36’s rapid burst-fire option helps minimise mains flicker and can reduce harmonic distortion, with typical levels potentially below 4%, depending on the installation and operating conditions.

Applications

The DMFC36 Driver Module is suitable for a wide range of industrial three-phase power-control applications, including:

• Industrial heating systems
• Three-phase electric furnaces
• Industrial ovens and heating elements
• AC motor control
• Power supplies and controlled rectifiers
• Electroplating equipment
• Transformer management
• Industrial soft starters
• Resistive load control
• Generator-powered heating systems
• High-impedance electrical supply applications

Benefits

• Precise Three-Phase Power Regulation: Provides flexible control of three-phase thyristor assemblies.
• Flexible Firing Options: Choose phase-angle, standard burst-fire or rapid burst-fire control.
• Reduced Supply Disturbances: Rapid burst firing helps minimise mains flicker.
• Improved Heating Stability: Rapid switching supports more consistent heater temperature control.
• Flexible System Integration: Multiple voltage and current input options simplify connection to industrial control systems.
• Automatic Operation: Phase-angle to burst-fire switching reduces the need for manual intervention.
• Reliable Monitoring: Onboard LED indicators provide clear operating and fault information.
• Straightforward Installation: DIN rail mounting supports integration into industrial control panels.

Safety & Installation

• Installation and commissioning must be carried out by suitably qualified electrical personnel.
• Always isolate the electrical supply before installing, connecting or servicing the module.
• Ensure the correct supply voltage configuration is selected using LINK J1.
• A suitable 24V AC/DC auxiliary supply with a minimum capacity of 500mA is required.
• Verify the control signal type and wiring before applying power.
• Ensure the thyristor assembly and pulse transformer outputs are connected correctly.
• Use appropriate external protection and semiconductor fusing for the complete power assembly.
• The DMFC36 has an IP20 protection rating and should be installed inside a suitable electrical enclosure.
• Follow the manufacturer’s wiring and installation instructions.