A Manufacturing Capability That Shouldn't Exist — But Does
In the global Electronic Manufacturing Services (EMS) industry, companies specialise. PCB assembly houses run SMT lines and wave soldering. Wound component manufacturers operate coil winding machines and core assembly stations. These are considered separate disciplines, served by separate suppliers, managed under separate purchase orders.
TOS Lanka breaks this convention. We manufacture custom wound components — transformers, inductors, EMI chokes, and ferrite core assemblies — alongside full PCB assembly, wire harness production, and box build integration in the same ISO-certified facility. This is not a recent addition or a marketing aspiration — it is a core competency inherited from our parent company, Tosslec Ltd., Kyoto, which has manufactured inductive components for decades.
Why This Matters for Your Product
If your product contains both assembled PCBs and custom inductive components — and many power electronics, lighting, industrial, and automotive products do — the conventional approach forces you to manage two entirely separate supply chains:
- Vendor A: Winds your custom transformers, ships them to...
- Vendor B: Assembles your PCBs, receives transformers from Vendor A, solders them onto the board
This creates multiple failure points: shipping delays between vendors, quality mismatches, finger-pointing when defects occur, and the administrative burden of coordinating two suppliers who have no relationship with each other.
The Single-Source Advantage
When both your custom transformer and the PCB it mounts on are manufactured in the same facility, under the same quality management system, by a team that understands both technologies:
- One purchase order — Simplified procurement and payment
- One shipping lane — No inter-vendor logistics to manage
- One quality discussion — Unified ISO 9001 quality system covering both disciplines
- One point of accountability — No vendor finger-pointing when issues arise
- Matched quality standards — Both components manufactured to identical quality criteria
- Design coordination — Our engineers understand both PCB and wound component requirements simultaneously
What We Wind
TOS Lanka's inductive components division manufactures a comprehensive range of custom wound components:
Transformers
Custom transformers for isolated DC-DC converters, flyback transformers for AC-DC power supplies, forward converter transformers, and signal transformers for telecommunications. Every transformer is wound to your exact specification — turns ratio, inductance, leakage inductance, and insulation class.
Inductors
Power inductors for buck, boost, and SEPIC topologies. Custom inductance values, saturation current ratings, and DCR specifications. From prototype quantities through production volumes.
EMI Chokes
Common-mode chokes for conducted emission compliance (CISPR 25 for automotive, CISPR 32 for industrial), differential-mode filter inductors, and line impedance stabilisation components. Critical for helping your product pass EMC certification.
Ferrite Core Assemblies
Complete ferrite core transformer assemblies including core selection, bobbin preparation, precision winding, termination, and encapsulation. We work with standard ferrite geometries (E-cores, toroidal, pot cores) as well as custom core shapes.
What We Assemble
Alongside our winding capability, TOS Lanka provides the full spectrum of EMS services:
- SMT Assembly — Panasonic high-speed placement with lead-free reflow
- Through Hole Assembly — Wave soldering, selective soldering, manual soldering
- Test & Inspection — AOI, ICT, X-ray, functional testing
- Conformal Coating — Environmental protection for harsh applications
- Wire Harness Assembly — Automotive and industrial cable harnesses
- Box Build Integration — Complete product assembly and packaging
Competitive Landscape: Why This Is Genuinely Rare
We are transparent about our competitive positioning. Here is how TOS Lanka's capability set compares to other EMS providers operating in South and Southeast Asia:
| EMS Provider | PCB Assembly | Wire Harness | Inductive Components |
|---|---|---|---|
| TOS Lanka | ✅ | ✅ | ✅ |
| GPV Group | ✅ | ✅ | ❌ |
| VarioSystems | ✅ | ✅ | ❌ |
| Syrma SGS | ✅ | ❌ | ❌ |
This three-pillar capability — PCB assembly, wire harness, and inductive components — is genuinely unique in the EMS competitive landscape. It is rooted in decades of Tosslec heritage and cannot be replicated overnight by competitors.
Applications That Benefit Most
Products that benefit from our dual capability include:
- Power supplies: Custom transformers mounted directly on the power PCB — designed and built together
- Motor drives: Line reactors, EMI chokes, and control PCBs from one source
- Automotive electronics: Ignition coils, sensor coils, and associated PCBAs
- LED lighting: Driver transformers and control boards assembled together
- Industrial controls: Current transformers for energy metering integrated with measurement PCBs
- Medical devices: Isolation transformers and patient-safety power supply boards
Quality Verification for Wound Components
Every inductive component manufactured at TOS Lanka undergoes comprehensive electrical testing:
- Inductance measurement at specified frequency and current bias conditions
- DC Resistance (DCR) verification against specification limits
- Turns ratio verification for transformers
- Insulation resistance testing between windings and winding-to-core
- Dielectric withstand (Hi-Pot) testing per safety specifications
- Saturation current measurement for power inductors
From Your Specification to Our Winding Machines
Whether you need a prototype run of custom transformers, a production supply of EMI chokes, or inductors wound to a precise specification — our inductive component team is ready to deliver. Share your component specifications alongside your PCB Gerber files, and we will provide a comprehensive manufacturing proposal covering both disciplines.
Request your custom component quote — or email dexter@toslanka.com with your specifications.