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Custom High Frequency Transformers

ConverNova is a custom high frequency transformer manufacturer based in Madrid, Spain. We design and build switching transformers for LLC, CLLC, dual active bridge, phase shift full bridge, flyback and forward converters, from a single prototype to production series with no minimum order quantity. You get a first design proposal with loss split, magnetizing and leakage inductance and hotspot temperature, usually within 24 hours, and prototypes in 4 to 8 weeks.

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Topologies

Built around your converter, not around a catalog part.

Tell us the topology and the waveform and the design starts there. These are the ones we are asked for most often, and the ones the specification form lists.

Resonant

LLC half bridge, LLC full bridge, CLLC, and SRC. Magnetizing and leakage inductance are design targets here, not by-products, because your resonant tank depends on both. For low profile resonant stages above roughly 200 kHz, a planar transformer is often the better build.

Bridge

Phase shift full bridge with centre tap or full wave rectifier, and dual active bridge. Interleaving and winding order chosen for the leakage your control loop expects.

Single switch and line

Flyback and forward, plus gate drive, current sense and 50 or 60 Hz isolation transformers when the application asks for them.

Specification range

What we can build.

If what you need sits outside this table, ask anyway. The answer is usually yes, and when it is no we say so.

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Frequency
50 and 60 Hz line, through to 2 MHz for SiC and GaN switching stages
Power
From a few watts to hundreds of kilowatts, single or multiple outputs
Cores
Ferrite (Ferroxcube, TDK), nanocrystalline (VAC, Hitachi), amorphous, powder (Magnetics, Micrometals). Custom machined geometries and production tooling available
Windings
Litz from 0.03 mm strands, triple insulated wire, copper foil, edge wound flat wire, planar on your PCB or on ours
Construction
Bobbin or bobbinless, tape wound, vacuum impregnated, varnished, potted in resin or in an aluminum housing
Isolation
Reinforced and functional isolation, creepage and clearance to the standard your application is qualified against
Temperature
Minus 55 to plus 125 degrees C depending on materials and insulation class
Test
Inductance, leakage, interwinding capacitance, DC resistance and temperature rise under your real waveform

What arrives

A design proposal, not a price list.

Usually within 24 hours of your specification, and before you have spent anything, the first proposal carries the numbers you need to judge the design. See how our custom magnetics design process works.

Loss distribution

Estimated core losses and winding losses, split, at your waveform and your switching frequency. Not a single efficiency figure with no working shown.

The inductances

Magnetizing inductance and leakage inductance, with the interleaving and winding order that produce them.

Thermal and mechanical

Expected hotspot temperature for your cooling method, and the dimensions, so you know it fits your keepout before anything is wound.

Construction

Transformer construction.

Foil, litz and taped windings, on stacked or gapped cores, terminated to leads or to pins.

A foil winding on a bobbin over a gapped stacked core
A transformer taped in amber polyimide, marked and lead terminated
A heavy copper winding filling the window of a taped core

Straight answers

Custom transformers, the usual questions.

What is the lead time for a custom transformer prototype?
Four to eight weeks from an agreed design, when the required raw materials are in stock. The engineering answer, with a first design proposal, is one we aim to send inside 24 hours.
What is the minimum order quantity?
There is none. Prototypes, samples and production come off the same drawing, so nothing gets redesigned when the volume arrives.
What frequency range do you cover?
From 50 and 60 Hz line frequency up to 2 MHz, designed for modern SiC and GaN switching semiconductors.
Which core materials do you work with?
Ferrite from Ferroxcube and TDK; nanocrystalline from VAC and Hitachi; amorphous alloys; and powder from Magnetics and Micrometals. When no standard geometry fits, we machine a custom core.
Can you hit a leakage inductance target?
Yes. And we will tell you honestly when the target fights the isolation you also asked for. Interleaving, winding order and the bobbin all move it. We measure it and put the number on the report.
Do you build to print, or do you design it?
Whichever your project needs. If you already have a working design, send us the drawing and we produce it. If you do not, we design the optimal transformer for you: optimal in efficiency, in performance and in cost.
Are you a transformer manufacturer or only a design house?
We design the transformer and we deliver it, from the first prototype to production series. The same drawing and the same bill of materials go from samples to volume.
Do you build custom flyback transformers?
Yes. Flyback is one of the most common requests, from auxiliary supplies to active clamp designs. Send the input range, outputs, switching frequency and isolation class.
Do you build custom pulse and gate drive transformers?
Yes, including gate drive transformers for SiC and GaN stages, where interwinding capacitance and isolation decide the design.
What do you need to quote a custom transformer?
Topology, switching frequency, input and output voltages, currents, isolation requirement and the space you have. A schematic and the waveforms are enough to start.

Start here

Send us your transformer spec.

Topology, frequency, voltages, currents, isolation and the space you have. Or just the schematic and the waveform. Engineering answer, we aim for 24 hours.

Send us your spec