Buying Custom Magnetics in Low Volume: 100 to 1,000 Pieces Without Prototype Pricing
The 300-Piece Problem Custom magnetics pricing is built around setup, not around material. A 300-piece order for a wound component carries the same winding programme, the same first-article inspection and often the same minimum core purchase as a 3,000-piece order, which is why the quoted unit price can look absurd at low volume. The buyer’s […]
Toroid vs EE vs Pot Core: Choosing the Right Shape for Your Application
Three Shapes, Three Different Sets of Compromises The core shape decides how much copper the window will hold, how well heat leaves the part, how much the winding costs to produce, and how much of the magnetic field escapes. Buyers usually inherit a shape from a previous design and never re-examine it; a shape review […]
Ten Questions to Answer Before You Approve Tooling for a Custom Magnetic Component
Tooling Is the Point of No Return In a custom magnetics project, the expensive mistakes are almost always made in the two weeks before tooling is approved. After that, a bobbin change means a new mould, a core change means a new supplier lead time, and a winding change means a new machine programme. Ten […]
Tariffs, Origin Rules and Trade Remedies: Sourcing Magnetic Components Without Surprises
Tariffs Are Now a Sourcing Variable, Not an Afterthought For a US or EU buyer of wound components, the landed cost of a Chinese-built transformer is no longer the supplier’s price plus freight. Duty rates, origin rules and anti-dumping exposure can move the number by 10–30 %, and they move faster than a qualification cycle. […]
What Must Be on a Transformer Test Report: A Buyer’s Audit Checklist
A Report That Cannot Be Used Is Not Evidence Most suppliers will send a test report when asked. Far fewer send one that lets a buyer verify that the part matches the drawing. Reports that list “tested: OK” against five lines are not quality evidence; they are a courtesy. This is the minimum content that […]
Copper vs Aluminium Windings in Custom Transformers: When Cheaper Metal Costs More
The Question Behind the Cost Request When a buyer asks a magnetics supplier to “look at aluminium to take some cost out”, the honest answer is that aluminium is not a cheaper version of copper — it is a different design with different failure modes. It works well in some applications and is genuinely poor […]
Insulation Class A to H for Transformers: What It Costs and When It Is Worth Paying For
Class Is a Limit, Not a Target Insulation class appears on nearly every transformer drawing, and is one of the most frequently misunderstood lines on it. Class B does not mean the part runs at 130 °C; it means the insulation system is qualified so that its hottest point does not exceed 130 °C in […]
How to Estimate Transformer Temperature Rise Before You Place the Order
Why Temperature Rise Is the Number Buyers Forget Most transformer specifications state inductance, turns ratio, hipot voltage and dimensions. Very few state the temperature rise the part is allowed to develop in the application. That single omission is behind a large share of field failures and of “the sample worked on the bench” arguments, because […]
Incoterms 2020 for Magnetic Components: Who Owns the Risk and the Cost
Incoterms Decide Who Owns the Risk, Not Just Who Pays Most purchase-order disputes on magnetic components are not about price or quality — they are about the point at which risk transfers and who is responsible for a shipment that arrives damaged or delayed. Incoterms 2020 answers those questions precisely, and the choice of term […]
Leakage Inductance: Design Parameter or Defect, and How to Hold It
Where the flux goes, the approximation that shows the levers, and the drawing fields that keep a target value in production.