Custom Transformers & Transformer Design

Custom power transformers are designed and configured to accommodate an application’s specific technical, environmental, and space requirements. From mounting styles to construction materials, each aspect of the transformer is optimized with the specific end-use in mind. At MPS Industries, we leverage our wide-ranging industry experience and advanced winding equipment to create custom transformers for a range of specialized applications.

Popular Custom Power Transformer Designs

Before designing a custom transformer, it is important to be aware of the main transformer types and their specific voltage transformation capabilities. Most transformers can be split into the following categories:

  • Single-phase: Single-phase transformers utilize single-phase alternating current as the input source. Consisting of one primary and one secondary winding, these devices are most often used to reduce the voltage to more suitable levels for low voltage residential or commercial heating and lighting applications and commercial electronics, such as television sets. While somewhat limited to lower-voltage uses, single-phase transformers are generally easier and less expensive to manufacture than three-phase transformers.
  • Three-phase: Three-phase transformers can be created by either combining three single-phase units or assembling a single unit with three sets of primary and secondary windings. The combined single-phase configuration involves three independently operating units, which reduces the risk of power interruption if one unit fails. However, the single three-phase assembly is lighter, smaller, and generally more affordable. Three-phase transformers are ideal for powering large motors, heavy-duty equipment, and other high-voltage applications.
  • Switch mode power supply (SMPS): SMPS transformers are compatible with DC to regulate the flow of electricity to DC sources using semiconductor switching techniques by stepping current up or down depending on the power regulation needs of the application. These transformers can accommodate varying load conditions while maintaining a consistent output voltage. Due to their lower energy consumption, reduced size, and heat dissipation capabilities, SMPS transformers are quickly replacing linear AC-to-DC power supplies. The switching converter consists of a control circuit and a power switching stage which converts the power from the input voltage to the output voltage. SMPS transformers are more efficient than traditional, linear transformers because their functionality allows for lower power dissipation. SMPS transformers are commonly used in applications in the medical, industrial, power distribution, and automotive industries.


Custom Transformer Design Considerations

After determining the basic type of transformer required to meet your needs, the following design factors should be considered to optimize your custom transformer for its application:

  • Power requirements: To achieve satisfactory power coupling and voltage regulation with minimal energy loss, transformer designers must consider various design trade-offs and make compromises based on the intended application’s power, efficiency, and size requirements. A well-designed transformer will be capable of converting incoming electricity to the voltage required by the load while minimizing various forms of loss.
  • Energy losses: When transferring power, transformers lose small amounts of energy due to the resistance of the windings as well as magnetic effects in the transformer’s core. In general, transformer designers aim for at least 95% efficiency.
  • Cooling requirements: Many components in transformers produce heat when in operation. For optimal performance, it is important to prevent the components from overheating. Consider whether a cooling element is needed for your design. Common cooling methods include convection, heat sink, and liquid cooling.
  • Skin effects: Skin effects are created by the propensity of high-frequency electrical currents to concentrate at the conductor’s surface. This results in a lower utilization below the conductor’s surface. To minimize this phenomenon, high-frequency transformers often utilize Litz wires, which consist of several smaller conductors woven together to form a single multi-strand wire.
  • Proximity effects: Proximity effects describe the eddy current losses resulting from the magnetic fields of nearby conductors in adjacent windings or layers. These effects can be counteracted in several ways, including:
    • Optimizing the number of turns/layers through careful core selection
    • Using foil winding layers or interleaved windings
  • Transformer ratings: Once the custom transformer is complete, the level of power it provides must be carefully measured and clearly defined on its nameplate. This rating, measured in volt-amperes (VA) or kilovolt-amperes (kVA), indicates the maximum output voltage and current that can be achieved during operation.
  • Safety requirements: Safe operation of transformers relies upon a well-engineered design. Consider the following safety requirements when designing your transformer: applicable military, medical, UL, telecom, or automotive standards; hi-pot requirements; high-voltage insulation requirements; UL EIS requirements; and required materials temperature class.
  • Switching topologies: The configuration of an SMPS transformer’s inductors, capacitors, rectifiers, and power-handling transistors is referred to as the topology of the transformer. We offer transformers optimized for a range of topology configurations, including flyback, forward, push/pull, gate drive, full bridge, half bridge, and phase shift full bridge.


Transformer Components

Successful transformer design depends on careful consideration of several key variables, including:

  • Materials
    • Conductor: Copper, aluminum, magnet wire
    • Core: Amorphous metals, ferrite ceramics, powdered iron alloys, high flux cores, metallic tape-wound cores, silicone steel
  • Conductor wire geometry
    • Litz
    • Round magnet
    • Rectangular magnet
    • Square magnet
  • Enclosure type (if required)
    • Stainless steel
    • Completely sealed
    • Indoor or outdoor
  • Mounting Type
    • Open
      • Brackets
    • Encapsulated
      • Needs to be encapsulated due to environment and environmental factors like humidity
    • Mounting accessories
      • Clips
      • Clamps
      • Brackets
    • Termination
      • Through-hole
      • Surface mount
      • Quick connect
      • Flying lead
    • Environment
      • Insulation materials
      • Encapsulated or potted for resistance to harsh environments
      • Heat-tolerant or flame-retardant tapes
      • Shock and vibration requirements
      • Temperature class rating requirements
      • Safety agency requirements
      • Thermal management

In addition to the core, wires, and mounting options, other components that are essential to a transformer’s performance include:

  • Bobbin
  • Tapes
  • Adhesives
  • Varnishes


Custom Designed Transformer Industry Applications

Custom transformers play a critical role in supporting current technologies and driving innovation in the following demanding industries:

  • Military
  • Alternative Energy
  • Automotive
  • Avionics
  • Industrial
  • Medical
  • Space

Examples of modern technologies that rely on custom transformers include:

  • Camera flash circuits
  • Igniters
  • Laser and xenon lighting flash tubes
  • Laser cutters used in industrial manufacturing
  • Laser measuring tools
  • Medical lasers
  • Military laser targeting technologies
  • Spark switches
  • Stun guns and electroshock devices


Custom Transformer Design Capabilities at MPS Industries

MPS Industries partners with clients across many industries to create custom power transformers for applications with challenging environmental or space demands. Whether you require slight modifications to an existing product or a completely customized unit, we can work with you to devise a solution that meets all your needs.

To learn more about our custom transformer design capabilities, please contact us today or request a quote.