Custom Transformers, Coils & Inductors for Scientific Research & Laboratory Equipment

Research instrumentation is an area where the usual tolerances don’t apply. RF coils that are “close” to the right resonant frequency show up as a degraded signal-to-noise ratio in every measurement. High-voltage transformers feeding measurement-grade electronics must be quiet  the noise floor is the spec, not an afterthought. Catalog parts, by definition, are designed for the average case; research equipment usually isn’t the average case.
Custom Coils USA manufactures custom transformers, RF coils, and high-Q air-core inductors for research institutions, instrument manufacturers, laboratory equipment OEMs, and national laboratories. We’re a VPI dry-type specialty shop. Minimum volumes aren’t a conversation we need to have  single units, prototype iterations, and small-batch production are core to how we work with R&D teams.

What We Build for Research & Laboratory Applications

High-Voltage Transformers for Research Instrumentation

We build dry-type, VPI-impregnated high-voltage transformers for research-grade applications  particle physics power supplies, X-ray generation systems, electron beam controls, and high-energy laboratory equipment. The harder design problem at elevated voltage isn’t the kV rating itself; it’s holding the voltage with low partial discharge, low coupling capacitance to the secondary, and a noise floor that doesn’t contaminate the measurement-grade electronics downstream.
Voltage and current interactions, the realistic envelope is a volt-ampere product, not a single voltage rating. A transformer that holds high voltage at very low secondary current is a different design problem than one delivering moderate voltage at higher current. We calibrate the build to the actual V×I your application requires, with output voltage, current rating, isolation class, and creepage geometry engineered to your specification.

Custom RF Coils for Spectroscopy, NMR & MRI Research

We wind custom RF coils to your resonant frequency, geometry, Q-factor, and coupling specification. Birdcage, surface, saddle, and solenoidal geometries; tuned to single-frequency or broadband operation. Your instrument’s sensitivity and resolution depend on the coil hitting the right frequency cleanly and coupling to the sample with the geometry your physics requires so we work from your specification, not from a standard product adapted to look like it fits.

High-Q Air-Core Inductors for Precision RF & Measurement Circuits

High-Q air-core inductors give you predictable inductance without core losses, saturation thresholds, or temperature-dependent permeability. For precision RF circuits, signal-generator output stages, impedance-matching networks, and measurement instruments where stability across frequency, current, and temperature matters more than physical size, an air core is the right architecture. We wind to your inductance, Q, self-resonant frequency, and current rating.

How We Work with Research Teams

R&D procurement doesn’t run on the same timeline as production sourcing, and we don’t treat it that way. Specifications change during development. Prototypes need to iterate often. Sometimes the first build reveals something about the physics that changes the winding spec.

• Prototype quantities : low minimum orders, no volume-based pricing conversations
• Engineer-to-engineer : you talk to the person who wound your part, not a rep reading your spec back to you
• USA manufacturing : prototype turnaround without waiting for international shipping or export controls
• Full test documentation with every build : calibration data, measured electrical performance, and any custom characterization your application requires; built to your specified UL system where applicable, with component-level documentation to support your end-product qualification path

Frequently Asked Questions

Q1: What voltage range do your research transformers cover?


Voltage and current interact the honest answer is a V×I product, not a single kV figure. A transformer holding high voltage at very low secondary current is a different design problem than one delivering moderate voltage at higher current, and the dry-type VPI envelope sets the upper bound on the V×I product, not on voltage alone. We calibrate to the specific output voltage AND current your application requires. The harder engineering problem at elevated voltage isn’t the rating itself  it’s holding the voltage with low partial discharge, low coupling capacitance to the secondary, and a noise floor that doesn’t contaminate measurement-grade electronics.

Q2: What’s different about high-voltage transformer design for measurement-grade research?


Three things beyond just voltage rating. First, partial discharge under continuous operation not just at flash test because PD pulses contaminate the noise floor of any measurement electronics on the secondary side. Second, low coupling capacitance between primary and secondary, so high-frequency content from the line side doesn’t bleed across into your signal path. Third, a winding geometry and shielding scheme that don’t add their own EMI signature. Standard industrial HV transformers prioritize voltage withstand and basic dielectric strength; research applications need all three.

Q3: Why do NMR and MRI systems need custom-wound RF coils?


Because the instrument’s sensitivity and resolution depend on the coil hitting its resonant frequency with the right coupling to the sample. Custom RF coils are wound to the frequency, geometry, and Q-factor your specific instrument requires. A catalog coil that’s “close” will degrade your signal-to-noise ratio in ways that show up in every measurement you take.

Q4: When should I use an air-core inductor instead of a ferrite-core design?

When you need inductance that doesn’t shift with frequency, current level, or temperature. High-Q air-core inductors have no core losses, no saturation threshold, and no permeability that drifts with thermal load. For precision RF circuits and scientific measurement instruments, predictability is more valuable than the size and weight advantage a ferrite core provides.

Q5: What are your lead times for custom research and laboratory magnetics?

4–8 weeks from finalized specification to delivery for prototype and small-batch work. R&D builds typically benefit from getting us involved early, while the spec is still in flux  when the design changes mid-build, we’d rather adjust the winding than restart the queue.