Custom EI PCB Transformers for Compact Power Supply Designs
Engineered with customized input voltage, output windings, rated power and pin layout for reliable integration into OEM circuit boards.
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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 Footprint Designed Around Your BoardPin spacing, row distance, pin diameter, seated height and maximum external dimensions can be developed from your PCB layout. This helps reduce board redesign and improves first-fit integration during prototype assembly. |
Stable Output Under Actual Load ConditionsThe transformer is calculated according to the required output voltage, current, duty cycle and acceptable regulation. Output performance is verified under the agreed input voltage, frequency and rated-load conditions. |
Controlled Temperature RiseCore size, magnetic flux density, copper current density, winding arrangement and insulation materials are selected together. This provides a practical thermal margin for enclosed control boards and continuously operated equipment. |
Low No-Load Current and Reduced Core LossThe number of turns, core stack and operating flux density are optimized for the specified mains frequency. This helps control standby loss, excitation current and unnecessary heating. |
Application-Specific Insulation DesignThe bobbin, winding barriers, insulation tape, creepage distance, clearance distance and dielectric-strength level are reviewed according to the end-product requirements. Functional, basic, supplementary or reinforced insulation can be evaluated. |
Quiet and Repeatable ProductionControlled winding tension, core assembly, impregnation or encapsulation help reduce mechanical vibration and audible hum. Approved drawings, BOMs and test limits improve consistency between samples and production batches. |
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?
Engineering Design Based on the Complete ApplicationECKO evaluates the input range, frequency, output load, voltage regulation, temperature rise, PCB space, enclosure ventilation and insulation requirements before releasing a design. The transformer is developed as part of the customer’s power circuit rather than selected only by voltage and VA. |
Controlled Specifications, Drawings and RevisionsEach approved project can be managed through a controlled product specification, dimensional drawing, pin diagram, BOM, process instruction and inspection plan. Engineering changes are recorded by revision, approval status and effective production lot. |
Qualified and Traceable Raw MaterialsCopper wire, electrical steel, bobbins, insulation tape, thermal protectors, terminals and encapsulation materials are purchased according to approved specifications. Incoming inspection and batch records help prevent unauthorized material substitution. |
Production Capacity with Process ControlEstablished in 2000, ECKO operates three workshops covering approximately 5,000m² with around 150 skilled workers. Winding, soldering, core assembly, impregnation, encapsulation and electrical testing are managed through defined production and inspection procedures. |
Quality Control from Sample to Mass ProductionCritical electrical parameters are confirmed during sample verification and transferred into the production test specification. Routine testing and batch traceability support stable repeat orders and more efficient customer incoming inspection. |
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
Step 1: Submit the Application RequirementsProvide the primary voltage, frequency, secondary voltage and current, available PCB space, operating environment, annual quantity and applicable safety requirements. |
Step 2: Engineering Feasibility ReviewECKO reviews the VA requirement, winding arrangement, core size, temperature-rise target, insulation construction, PCB footprint and potential technical risks. |
Step 3: Technical Proposal and QuotationWe provide a proposed electrical configuration, construction type, estimated dimensions, testing plan, tooling requirements and commercial quotation. |
Step 4: Specification and Drawing ApprovalThe customer reviews the electrical specification, outline drawing, PCB footprint, pin assignment, polarity and critical tolerances before sample production. |
Step 5: Prototype ManufacturingSamples are produced using the approved materials and process route. Electrical and dimensional test records can be provided according to the agreed project plan. |
Step 6: Sample Verification and Customer ApprovalOutput voltage, load regulation, no-load current, temperature rise, dielectric strength, dimensions and PCB fit are confirmed before production release. |
Step 7: Controlled Mass ProductionThe approved BOM, drawing revision, winding data, process instructions and test limits are released to production. Routine tests and batch identification are applied according to the inspection plan. |
PCB Transformer FAQ
1. What is a PCB transformer?
A PCB transformer is a compact, mains-frequency transformer designed for direct through-hole mounting on a printed circuit board. It converts the input voltage to one or more lower AC output voltages while providing the required electrical isolation between the primary and secondary circuits.
2. What information should I provide when requesting a custom PCB transformer?
Please provide the input voltage and frequency, each secondary voltage and current, load type, operating duty cycle, maximum dimensions, PCB footprint, ambient temperature, insulation requirements and estimated annual quantity. A PCB layout, dimensional drawing or existing transformer sample will help us evaluate the project more accurately.
3. How do I select the correct VA rating for a PCB transformer?
The basic VA requirement is calculated by multiplying each secondary voltage by its rated current and adding the results together. Additional design margin may be required for rectifier circuits, capacitive loads, peak currents, voltage-regulation requirements and elevated ambient temperatures.
4. Should I specify the secondary voltage at no load or full load?
For most custom projects, the required secondary voltage should be specified at the actual operating load. A transformer’s no-load voltage is normally higher than its rated-load voltage because of winding resistance and internal voltage drop. Please provide both values if your circuit has a strict voltage range.
5. Why is the measured no-load voltage higher than the rated output voltage?
The rated secondary voltage is usually defined at a specified load. When the transformer operates without a load, there is almost no voltage drop across the windings, so the measured output voltage increases. The difference between the no-load and full-load voltage is described as voltage regulation.
6. Can a PCB transformer be designed for a bridge rectifier and filter capacitor?
However, a rectifier-capacitor input draws short, high-current charging pulses rather than a smooth sinusoidal current. Please provide the required DC output voltage, DC load current, rectifier arrangement and filter capacitance so that the transformer can be sized correctly for winding heating and voltage regulation.
7. Can you manufacture PCB transformers with multiple secondary windings?
A PCB transformer can be designed with single, dual, center-tapped or multiple independent secondary windings. Each winding’s voltage, current, insulation relationship and connection method should be clearly defined in the approved electrical specification.
8. Can the secondary windings be connected in series or parallel?
Identical secondary windings may be designed for series or parallel connection. Series connection increases the available voltage, while parallel connection increases the available current. Correct winding polarity must be followed, and only windings specifically designed with matching characteristics should be connected in parallel.
9. Can you produce a PCB transformer with dual 115V/230V primary windings?
Two matched primary windings can be connected in parallel for approximately 115V operation or in series for approximately 230V operation. The required connection diagram, pin assignment and safety instructions will be defined on the approved drawing.
10. Can the same PCB transformer operate at both 50Hz and 60Hz?
Yes, if it is designed and rated for 50/60Hz operation. A transformer designed only for 60Hz may experience excessive magnetic flux, no-load current and heating if operated at 50Hz at the same voltage. The lowest intended operating frequency should therefore be stated before design approval.




