H01F 27/38
Auxiliary core members
Official title: Auxiliary core members; Auxiliary coils or windings
H01F27/38 (Auxiliary core members) appears on 665 US grants and 881 published applications in this corpus.
Search patents in H01F- Granted patents
- 665
- Published applications
- 881
- Assignees
- 418
- Inventors
- 1,679
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 4 | 0 |
| 1978 | 2 | 0 |
| 1979 | 1 | 0 |
| 1980 | 1 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 1 | 0 |
| 1986 | 3 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 0 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 1 | 0 |
| 1994 | 2 | 0 |
| 1995 | 3 | 0 |
| 1996 | 2 | 0 |
| 1997 | 0 | 0 |
| 1998 | 3 | 0 |
| 1999 | 2 | 0 |
| 2000 | 1 | 0 |
| 2001 | 4 | 0 |
| 2002 | 1 | 7 |
| 2003 | 5 | 5 |
| 2004 | 9 | 20 |
| 2005 | 6 | 15 |
| 2006 | 17 | 22 |
| 2007 | 18 | 21 |
| 2008 | 13 | 33 |
| 2009 | 19 | 35 |
| 2010 | 18 | 32 |
| 2011 | 21 | 12 |
| 2012 | 28 | 17 |
| 2013 | 9 | 21 |
| 2014 | 11 | 35 |
| 2015 | 15 | 46 |
| 2016 | 27 | 26 |
| 2017 | 37 | 37 |
| 2018 | 38 | 74 |
| 2019 | 43 | 69 |
| 2020 | 46 | 52 |
| 2021 | 44 | 62 |
| 2022 | 53 | 60 |
| 2023 | 51 | 54 |
| 2024 | 40 | 44 |
| 2025 | 35 | 49 |
| 2026 | 23 | 33 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Compensation structure for reducing circulating current in window of transformer and transformer comprising compensation structure22 Sep 2026US 12,744,155 B2Siemens Energy Global GmbH & Co. KG
- Contactless electrical energy transfer device18 Aug 2026US 12,709,170 B2Airbus SAS
- Coupled inductor18 Aug 2026US 12,712,116 B2Cyntec Co., Ltd.
- Multiphase buck converters with integrated coupled inductors and controllable coupling18 Aug 2026US 12,712,429 B2Virginia Tech Intellectual Properties, Inc.
- Control device for power conversion device28 Jul 2026US 12,695,026 B2Honda Motor Co., Ltd.
- An integrated inductor27 Aug 2026US 2026/0253783 A1Aalto University Foundation sr
- Multiphase system comprising power converter27 Aug 2026US 2026/0254352 A1Mitsubishi Electric Corporation
- Power converter and magnetic element27 Aug 2026US 2026/0254361 A1Delta Electronics, Inc.
- Electromagnetic interference filter20 Aug 2026US 2026/0246438 A1Lite-On Technology Corporation
- Integrated magnetic assembly for a multiphase dc-to-dc power converter13 Aug 2026US 2026/0237554 A1Delta Electronics (Thailand) Public Co., Ltd.
Most cited
By later US patents
- Planar transformer power supply266US 7,502,234 B2Aaron Medical Industries, Inc. · 2009
- Integrated-magnetic apparatus210US 5,726,615 A1998
- Ferrite core185US 6,501,362 B1UMEC USA, Inc. · 2002
- Transformer construction143US 8,410,889 B2Enecsys Limited · 2013
- In situ oxidation of subsurface formations122US 7,866,386 B2Shell Oil Company · 2011