Custom Control Transformers

What is a Control Transformer?

A control transformer steps down high primary voltages to a lower secondary voltage. It provides consistent, low-voltage power for operating control circuits and their components. Each unit is specifically engineered to meet the precise electrical and mechanical needs of an application.

These transformers are designed for superior voltage regulation under demanding loads. Electromagnetic components like relays and solenoids create a large inrush current upon energization. The transformer maintains a stable output voltage during these surges to prevent control system malfunctions.

Made In the U.S.A. Custom Control Transformers

At Altran, we centralize all engineering, purchasing, quality, and production operations at our Crystal Lake, Illinois, facility. Housing these teams in the same location streamlines operational feedback and protects client intellectual property. 

In-house technicians wind every coil and perform encapsulation. They verify electrical parameters throughout production before conducting environmental stress tests. Our quality control department performs a final verification of all performance and safety standards before a transformer is shipped.

Research & Development Control Transformer Capabilities

Altran is a custom control transformer manufacturer in Illinois that engineers and builds products that meet precise current, environmental, and voltage requirements. Every unit we produce achieves high efficiency and operational safety while delivering consistent reliability throughout its long service life.

We collaborate directly with clients throughout prototype development and production phases. This approach ensures our designs align with their electrical, mechanical, and performance requirements—and that every transformer is rigorously tested to meet precise electrical, thermal, safety, and dimensional specifications.

Supported Core Geometries:

• EI Laminations
• UI Laminations 
• Toroidal Split Bobbin 
• Custom Low-Profile 
• Fully Custom Geometries (Designed & Fabricated In-House)

Design Capabilities:

• Primary voltages from 120 V to 600 V (per application) 
• Secondary voltages tailored to customer requirements (commonly 12 V, 24 V, 120 V) 
• Power levels from a few VA to several kVA 
• High inrush current capability for industrial loads 
• Built-in fusing, shielding, or surge suppression (as specified) 
• Low-noise, low-leakage inductance designs for sensitive electronics

Custom-Only Solutions

Every control transformer we build is 100% custom — tailored from the ground up to meet your application’s electrical, mechanical, and compliance needs. We do not supply off-the-shelf control transformers. 

Each transformer moves through a documented construction and testing process to validate it against all customer requirements. This ensures full traceability and performance verification for every unit.

Material Selection for Application-Specific Performance

The materials used in a control transformer’s construction directly determine its performance and reliability. The proper selection of core, winding, and insulation materials allows the unit to meet specific electrical, thermal, and mechanical requirements.

Our engineering process evaluates the interaction between materials to achieve specific performance goals:

Stable Voltage Regulation: Altran technicians select high-grade silicon steel cores and low-resistance copper windings to manage high inrush currents from electromagnetic devices. This design minimizes voltage drops and ensures consistent power for sensitive control circuits.

Industrial Durability: High-temperature insulation systems and full epoxy encapsulation protect windings from moisture, vibration, and industrial contaminants. These materials ensure long-term operational reliability in demanding factory environments.

Integrated Safety & Compliance: We integrate components like terminal blocks and fuse holders directly into the transformer’s structure for enhanced safety and easier installation. Material choices ensure compliance with UL, CSA, and CE standards for control panel applications.

Compact Panel Integration: We utilize high-density winding techniques and thermally efficient core geometries to reduce the transformer’s physical footprint. This allows for easier integration into space-constrained industrial control panels without sacrificing performance.

Effective Thermal Management: Our material selection focuses on minimizing heat generation and maximizing dissipation within the transformer’s design. This prevents overheating in enclosed control cabinets and protects adjacent electronic components.Long-Term Reliability: We use robust bobbin materials and Class or higher insulation systems to withstand long-term thermal and electrical stress. This construction ensures a consistent and predictable service life for the control transformer.

 

Customers We Serve

Altran designs and manufactures custom control transformers for a broad range of applications, OEMs, and technology developers across many different industries, including:

• Machine Tools, Machine Tool Builders & Manufacturing Equipment
• Factory Automation & Robotics
• HVAC & Building Control System Manufacturers 
• Power Distribution Systems & Power Supply Manufacturers 
• Test & Measurement Equipment Makers 
• Defense & Aerospace Electronics & Contractors 
• Renewable Energy Equipment 
• Makers Medical Equipment Manufacturers (non-patient contact) 
• High-Reliability Research & Development Teams

Altran Custom Control Transformers

We apply over 40 years of experience to the design and manufacturing of custom control transformers. This expertise allows our engineers to solve your most demanding power regulation challenges. Click below to learn more and get a quote.

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