PCB Mount EI Transformers with Custom Voltage Outputs
Available with single, dual or multiple secondary windings to meet the power requirements of industrial and electronic control boards.
- Overview
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Custom PCB Transformers Engineered for Your Circuit Board
Compact through-hole PCB Transformer with customized input voltage, output windings, rated power, pin layout and insulation construction. ECKO designs each transformer around your load requirements, PCB footprint, temperature-rise target and applicable safety requirements.
From initial electrical calculations to approved drawings, controlled production and routine electrical testing, we help OEM customers integrate reliable mains-frequency power conversion directly into their PCB assemblies.
Typical PCB Transformer Specifications
| Parameter | Typical Range / Available Options |
|---|---|
| Product Type | Open-frame, vacuum-impregnated or fully encapsulated PCB transformer |
| Rated Power | 0.5 VA to 100 VA typical; higher ratings subject to engineering review |
| Primary Voltage | 100V, 110V, 115V, 120V, 200V, 220V, 230V or 240V AC; single or dual primary |
| Secondary Voltage | 3V to 48V AC per winding typical; other voltages available |
| Output Configuration | Single, center-tapped, dual or multiple secondary windings |
| Frequency | 50Hz, 60Hz or 50/60Hz |
| Core Material | EI laminated electrical steel core selected according to power and temperature-rise requirements |
| Winding Material | Copper winding wire |
| Insulation Class | Class B 130°C or Class F 155°C |
| Dielectric Strength | Project-specific; 3.0–4.0kVAC primary-to-secondary options commonly available |
| Temperature Rise | Defined according to rated load, ambient temperature, enclosure and insulation class |
| Mounting Method | Through-hole PCB pins |
| Pin Configuration | Custom pin count, pitch, row spacing, diameter, length and polarity marking |
| Protection Options | Thermal fuse, resettable thermal protector or external PTC coordination |
| Shielding Options | Electrostatic shield, inter-winding shield or magnetic shielding where required |
| Operating Temperature | Typical design range from -20°C to +70°C, depending on the material system |
| Compliance Options | Construction designed for applicable IEC, EN or UL requirements; approval is model-specific |

Specification notice: The values above represent typical engineering capabilities rather than one fixed catalog model. Final electrical ratings, dimensions, tolerances and test limits are defined by the customer-approved specification and dimensional drawing.
PCB Transformer Product Advantages
PCB Transformer Customization Options
| Customization Area | Available Options |
| Electrical Input | Primary voltage, voltage range, 50Hz/60Hz frequency, single primary or dual primary |
| Electrical Output | Single output, dual output, multiple windings, center tap, series/parallel connection |
| Rated Power | VA rating calculated according to each secondary load and operating duty cycle |
| Voltage Regulation | Output voltage adjusted according to the required full-load voltage |
| PCB Footprint | Custom pin position, pitch, row spacing, mounting grid and keep-out area |
| Product Dimensions | Maximum length, width, height, seated height and weight |
| Insulation System | Class B or Class F; functional, basic, supplementary or reinforced insulation |
| Dielectric Strength | Customer-defined or standard-based Hi-Pot level and test duration |
| Thermal Protection | Internal thermal fuse, resettable protector or external protection coordination |
| EMI Control | Electrostatic shield, inter-winding shield and optimized winding arrangement |
| Environmental Protection | Open-frame, vacuum impregnation, tape wrapping or fully encapsulated construction |
| Noise Control | Reduced flux-density design, controlled core assembly and impregnation |
| Identification | Customer part number, polarity mark, date code, batch code and private label |
| Documentation | Product specification, dimensional drawing, pin diagram, test report and material declarations |
| Packaging | Individual trays, partitioned cartons, export cartons and pallet packaging |
Why Choose ECKO for Custom PCB Transformers?
PCB Transformer Tests and Reference Standards
Routine Production Tests
| Test Item | Test Purpose | Typical Inspection Plan |
| Visual Inspection | Workmanship, label, polarity mark, pin condition and product appearance | Routine or sampling |
| Dimensional Inspection | Outline dimensions, seated height, pin pitch and pin position | Sampling or critical dimensions |
| Winding Resistance | Checks conductor continuity and winding consistency | Routine |
| Turns Ratio / Output Voltage | Verifies output voltage and winding polarity at the specified input | 100% routine test |
| No-Load Current | Confirms excitation current, core assembly and winding consistency | 100% or agreed inspection plan |
| No-Load Loss | Evaluates standby core and winding loss | Sampling or qualification |
| Load Voltage and Regulation | Confirms rated-load output voltage and voltage drop | Sample and periodic verification |
| Insulation Resistance | Checks insulation between windings and accessible conductive parts | Routine or sampling |
| Dielectric Strength / Hi-Pot | Verifies the specified insulation withstand level | 100% at the approved test level |
| Temperature Rise | Confirms thermal performance under defined mounting and load conditions | Type or qualification test |
| Audible Noise | Evaluates hum and mechanical vibration at the specified input | When controlled by the specification |
| Solderability | Confirms PCB pin wetting and resistance to soldering heat | Qualification or sampling |
Custom PCB Transformer Development Process
PCB Transformer FAQ
1. What is the difference between an open-frame and an encapsulated PCB transformer?
An open-frame transformer is generally smaller, lighter and more economical. A fully encapsulated transformer provides better protection against moisture, dust and mechanical vibration, but normally has different thermal behavior, dimensions and tooling requirements.
2. Can you match our existing PCB footprint?
We can review your PCB layout, hole positions, keep-out area and maximum component height. Final pin tolerances and PCB hole diameters should be confirmed through an approved dimensional drawing.
3. Can the transformer dimensions be customized?
Yes, within the limits of electrical power, insulation distance, core size and temperature rise. Reducing one dimension may require increasing another dimension or accepting different thermal and regulation performance.
4. What is the typical temperature rise of a PCB transformer?
Temperature rise is not one fixed value for every model. It depends on the VA rating, ambient temperature, enclosure ventilation, core flux density, winding current density and insulation class. ECKO can design to an agreed maximum temperature-rise target and verify it on the sample.
5. Can you reduce no-load current, standby loss or audible hum?
These characteristics can be improved through core selection, increased turns, lower flux density, controlled core assembly, winding arrangement and impregnation. The required limits should be stated before the transformer size and price are finalized.
6. Can you add an electrostatic shield?
A shield can be placed between the primary and secondary windings to reduce capacitive coupling and common-mode noise. The shield lead and grounding method must be shown in the customer’s circuit and pin diagram.
7. Can you install a thermal fuse inside the transformer?
One-shot thermal fuses and resettable thermal protectors can be evaluated according to the operating temperature, insulation system and abnormal-condition strategy. The protection temperature and electrical rating must be specified.
8. Do you perform 100% Hi-Pot testing?
Hi-Pot testing can be included as a 100% routine production test. The test voltage, duration, leakage-current limit and test points are defined by the approved specification and applicable standard.
9. Can you provide UL- or CE-related documentation?
Compliance and certification are model-specific. ECKO can evaluate the construction against relevant IEC, EN or UL requirements and provide available material declarations, test records or certification documents for the approved model. Certification scope should be confirmed before ordering.
10. What is the typical sample lead time?
Custom engineering samples are commonly completed within approximately 7–15 working days after the specification and drawing are approved. The exact schedule depends on bobbin availability, tooling, encapsulation requirements and qualification testing.
11. Can you replace an obsolete or discontinued PCB transformer?
Please provide an original sample, electrical ratings, pin diagram, PCB footprint and application information. A physical sample alone may not contain enough information to determine the required insulation system, temperature rise or safety classification.




