What Can West Coast Magnetics Design, Build, and Test? A Capabilities Overview

Published by West Coast Magnetics, July 2026, based on our 2024 company capabilities brochure (available for download below); content reviewed and confirmed current as of publication.

West Coast Magnetics (WCM) designs and manufactures custom magnetic components, RF filters, and electronic assemblies in-house, from 60 Hz to 100 MHz and in power magnetics up to 10 kW. The range spans isolation transformers, SMPS transformers, buck and boost inductors, resonant inductors, RF transformers, gate-drive and current-sense transformers, common-mode chokes, and multichannel RF filters. Design, manufacturing, and NIST-calibrated test all happen under one roof, under ISO 9001 and ISO 13485, backed by more than 1000 successful custom designs since the company was founded in 1974.

Custom magnetics are transformers and inductors engineered to a specific application’s electrical, thermal, and dimensional requirements rather than pulled from a catalog. WCM designs the core, bobbin, and winding in-house, without depending on off-the-shelf geometries, which is what lets a design meet targets that standard parts cannot.

What WCM Designs

This article is an overview; WCM’s custom magnetics design and manufacturing capabilities page is the primary reference for the full capability set and to start a custom project.

WCM designs linear, switching-power, and RF transformers and inductors across a 60 Hz to 100 MHz frequency range, with power magnetics rated up to 10 kW. The component families include:

• Isolation transformers and SMPS transformers (the WCM420 switch-mode family outputs 500 W to 5,000 W)
• Buck and boost inductors and resonant inductors for switching converters
• RF transformers, gate-drive transformers, and current-sense transformers
• Common-mode chokes for noise attenuation across a wide frequency range
• High-power multichannel RF filters, tunable across 100 kHz to 50 MHz
• High-voltage transformers and wireless signal and power-transfer magnetics
• Tuned RF inductors held to a ±0.5% tolerance, and coils made from bondable wire

Each of these is a starting point for a custom design, not a fixed catalog part. For the specific design guidance behind each family, see the resource articles on reducing winding losses in high-frequency inductors, SMPS transformer design, RF filter design, and nanocrystalline common-mode chokes.

Design and Engineering

WCM designs its own inductive components in-house, drawing on all common magnetic materials: ferrites, iron powder, silicon steel and other laminations, Kool Mu, and MPP. The engineering toolkit covers 3D modeling in SolidWorks, 2D modeling in AutoCAD, power-magnetic-device simulation, thermal simulation, and custom analysis in Python.

Design is paired with a Quality-by-Design discipline: root cause analysis, PFMEA and DFMEA, process validation, and UL/CSA/VDE/TUV compliance. Before any design reaches the floor, it goes through a pre-production design review that checks manufacturability, tolerance stack-up, material compliance, and reliability. WCM’s engineers bring experience from Silicon Valley technology companies across power electronics, SMPS control, and FPGA/CPLD design.

Manufacturing

WCM manufactures in North America, with prototyping and mid-scale build in Stockton, California and high-volume production in Tecate, Mexico. Manufacturing capabilities include:

• Automated and manual toroidal winding, and automated and manual bobbin and coil-form winding
• Windings in solid wire, litz wire, and copper foil
• Soldering and termination to J-STD-001 and IPC-610
• Potting, impregnation, coating, and baking
• Mechanical and electrical assembly

Test and Evaluation

Every build is verified on NIST-calibrated equipment against a standard of zero defect, 100% yield. WCM’s test capabilities include:

• DCR measurement to 0.5 microohms
• Hipot testing from 100 V to 50 kV
• Surge testing to 4 kV
• Inductance, capacitance, Q, impedance, and phase angle across 60 Hz to 100 MHz
• Turns ratio and phasing, and fully automated transformer testing

The quality team is certified in printed-circuit-assembly inspection to IPC-610 standards, and all test equipment is calibrated to NIST standards.

Electronic Manufacturing Services

Beyond magnetics, WCM provides turnkey electronic manufacturing services (EMS): advanced assemblies with traceable documentation, built and tested by trained staff. EMS capabilities include rapid prototype services, turnkey assembly, validation and test, printed-circuit assembly, chassis and box build, machined parts, injection molding, wire and cable harnessing, and kanban and inventory management. WCM also holds IPC-620 certification for cable and wire-harness assembly.

Patents and Technology

WCM’s design work is backed by its own intellectual property. The company holds patents on a multichannel highly parallel notch filter, an isolated RF power transformer, and a low-loss winding for gapped SMPS inductors. WCM also uses proprietary winding and insulation techniques developed in-house to reduce parasitics and optimize performance at high frequencies.

Markets and Quality Certifications

WCM designs and manufactures for semiconductor manufacturing, test and measurement, medical, military and aerospace, communications, and industrial markets. The company’s largest markets are manufacturers of semiconductor processing equipment and medical device companies, and it has completed more than 500 designs for the medical device industry.

WCM is certified to ISO 9001 and ISO 13485, holds IPC-610 and IPC-620 certifications, and operates an ITAR-certified facility in Stockton. The ISO 13485 scope focuses on risk management across the product life cycle and supports customer traceability and documentation for FDA submissions. For the medical vertical specifically, see designing transformers and inductors for medical devices; for a worked high-power example, see the EV charger transformer case study.

When standard components don’t fit your needs, our teams will engineer a solution.

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