Custom High-Voltage Transformers

Altran designs and builds custom high-voltage transformers for a wide range of industries. Every unit is engineered to the customer’s exact electrical, mechanical, and environmental specifications rather than selected from a product catalog. Regular off-the-shelf units cannot meet the voltage, insulation, and performance demands of many critical applications.

As a custom high-voltage transformer manufacturer, we bring decades of magnetic component engineering to high-voltage applications where standard solutions fall short. Our engineering team works directly with customers from specification through delivery to address voltage requirements, form factor constraints, and compliance needs. All design and manufacturing takes place at our Crystal Lake, Illinois facility, where quality is controlled at every stage of production.

Custom vs. Off-the-Shelf High-Voltage Transformers

Standard high-voltage transformers are manufactured to fixed voltage ratings, form factors, and insulation classes with no room for application-specific requirements. Turns ratios, creepage/clearance distances, dielectric withstand ratings, and secondary winding configurations are predetermined by the manufacturer rather than your application. Engineers working with unusual input/output voltages, tight physical envelopes, or demanding environmental conditions frequently find that off-the-shelf units require costly workarounds or fail to meet specifications entirely.

At Altran, we do not supply off-the-shelf transformers. Instead, we build every unit to your exact specifications. Voltage configuration, insulation material, core geometry, and environmental ratings are all determined by what your application demands. You receive a transformer engineered for your circuit from the start, without the compromises that come with forcing a standard unit into a non-standard application.

Our customers can specify a wide range of parameters:

• Turns ratio configured to your exact input/output voltage requirements

• Secondary winding count and tap points (determined by your circuit design)

• Core material selected for your frequency range and loss profile

• Potting and encapsulation options for moisture, vibration, and altitude environments

• Creepage and clearance distances are designed for your application voltage class

Standard vs. Customized Transformers

	Off-the-Shelf	Custom (Altran)
Voltage configuration	Fixed	Designed to spec
Insulation system	Standard class	Application-specific
Form factor	Catalog dimensions	Built to your envelope
Volume flexibility	High MOQ	Prototype to production
Lead time	Stock dependent	Scheduled for your project
Compliance	General certifications	Application-matched
Design support	None	Direct engineering collaboration

Prototyping and Low-To-Mid Volume Flexibility

Large transformer OEMs set minimum order quantities that make custom prototyping impractical for many engineering programs. We support low- to mid-volume production runs, so your team can develop and validate a custom high-voltage transformer design before committing to full production quantities. 

Prototype units come off the same production floor to the same standards as full-production units, so your electrical and mechanical validation carries over without requiring changes at scale. That consistency protects your timeline and eliminates the risk of a redesign after validation.

High-Voltage Design and Engineering Capabilities

We design the primary voltage, secondary voltage, frequency, and power ratings your application requires. Core geometry options, including EI laminations, ferrite cores, toroidal cores, and custom configurations, are selected for efficiency, size, and magnetic output at elevated voltages. Winding configurations, such as multi-tap secondaries and split-bobbin arrangements, are determined by your circuit topology and isolation requirements.

Our engineers work directly with you at the specification stage to optimize each unit for thermal output, efficiency, and manufacturability. High-voltage design requires careful attention to dielectric strength, creepage and clearance distances, and the selection of insulation systems. We resolve all three during the engineering phase rather than at the test bench. We resolve all three during the engineering phase rather than at the test bench. Compliance requirements, including UL, CSA, RoHS, IEEE, and IEC, are built into our process from the start, with ITAR and NADCAP readiness available for regulated industries.

Insulation Systems and Dielectric Performance

High-voltage transformers place demands on insulation materials that standard power transformer construction cannot meet reliably over time. We specify Kapton film, Nomex paper, and layered dielectric systems based on the operating voltage class, temperature rating, and dielectric withstand required by your design. Material selection directly affects the partial discharge inception voltage, long-term dielectric stability, and the transformer’s ability to withstand continuous high-voltage stress.

Epoxy encapsulation and vacuum pressure impregnation are applied where moisture ingress, altitude derating, or vibration resistance are part of your design requirement. Interlayer insulation and creepage and clearance distances are engineered to exceed minimum safety standards for your application’s voltage class. That construction maintains dielectric integrity throughout the unit’s service life, rather than only at the initial electrical test.

Insulation materials and processes used in our high-voltage transformers:

• Kapton film: high-temperature, high-voltage interlayer insulation with strong dielectric properties

• Nomex paper: thermal class H (180°C) and dielectric barrier material for winding separation

• Epoxy encapsulation: seals the winding assembly and dielectric barrier against moisture, dust, and mechanical stress

• Vacuum pressure impregnation (VPI): eliminates voids in the winding that can become partial discharge sites

• Creepage and clearance: designed to IEC 60664 and the applicable end-product standards for your application, including IEC 61558, IEC 62368-1, and IEC 60601-1

American-Made Quality and Testing

Every Altran high-voltage transformer is designed and manufactured at our facility in Crystal Lake, Illinois. Domestic production gives us direct control over material sourcing, build quality, and your schedule, without the variability of offshore manufacturing. Our quality system follows ISO 9001 principles, and our facility supports UL, CSA, CE, and RoHS requirements for regulated and commercial applications.

High-voltage transformers require electrical testing that goes beyond standard production checks. Every unit undergoes hi-pot dielectric withstand testing before shipment, and partial discharge testing is performed when your application requires verification that no internal ionization occurs at operating voltage. Thermal and load testing validate that each design performs to your specifications under real operating conditions rather than only at no load.

Industries We Serve

Altran has decades of experience working with a wide variety of industries, including:

• Medical imaging equipment, including X-ray, CT, and MRI power supplies

• Oil and gas exploration instrumentation

• Laser power supplies, including CO2, Nd: YAG, and excimer systems

• Industrial automation and high-voltage test equipment

• Power electronics and high-voltage power supplies

• Alternative and renewable energy systems

• Aerospace and defense applications with ITAR readiness

Altran Custom HV Transformers

Altran has over forty years of experience in designing and manufacturing custom high-voltage transformers for a variety of applications. We have the knowledge and production know-how to deliver high-performing and long-lasting customized solutions.

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