Invalidity dossier
US 6922883
Method for making a non-linear inductor
Current assignee: ABB Schweiz AG
Added 8/26/2026, 12:48:53 AM
Active provider: DeepSeek · deepseek-v4-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US6922883 — Method for Making a Non-Linear Inductor
Title: Method for making a non-linear inductor
Patent number: US6922883B2
Assignee/current assignee: ABB Schweiz AG (original assignees ABB Oy and ABB Inc USA)
Priority date: 2002-09-11; Filing date: 2003-08-06; Publication/grant date: 2005-08-02
Application: US10/635,313; inventors Kalyan P. Gokhale, Alpo K. Vallinmäki, Nicklas Jan Anders Sodo
Status (per source): Expired – Lifetime, expires 2022-10-06
Purpose. The invention relates to the input-side rectifier in an ac drive system, and specifically to inductors used there. Such rectifiers draw non-sinusoidal currents, producing harmonics with adverse effects (energy losses, malfunction of sensitive equipment). The patent states the invention reduces % THD of line current by incorporating one or more non-linear inductors in the ac or dc side of rectifier circuits — especially at partial loads — and also reduces current-ripple stress on the filter capacitor at partial loads.
Plain-language scope (from the supplied definitions/abstract material).
- A method for making a non-linear inductor from magnetic material: providing an air gap having two or more widths, and adjusting each air gap width or the width of magnetic material adjacent the air gap to produce a desired non-linear inductance characteristic.
- A method from laminations of magnetic material having different widths: stacking the laminations to produce an air gap with two or more widths, and adjusting the air gap width and number of laminations to produce the desired non-linear inductance characteristic.
- A further variant: stacking predetermined numbers of laminations of one width and another width to produce a two-or-more-width air gap, and adjusting their arrangement in the stack to produce the desired characteristic.
The excerpt references FIGS. 1–12, including rectifier schematics (dc-side and ac-side filter inductors), current/line-current waveforms, and an inductance-versus-operating-current curve for linear vs. non-linear inductors.
What the excerpt does not establish. The supplied text is partial: the description is cut off mid-FIG. 12 sentence, and full claims (only "57" is noted) and any claim language are not provided. No comparison data, dimensions, materials specifics, or dependent-claim limitations are shown. It also does not establish litigation, ownership transfers beyond the noted reassignment, validity, or prior art.
Generated 10/1/2026, 10:03:57 PM
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Assignment history
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Prior art
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