H01F 38/00
Adaptations of transformers or inductances for specific applications or functions
H01F38/00 (Adaptations of transformers or inductances for specific applications or functions) appears on 7,181 US grants and 7,964 published applications in this corpus.
Search patents in H01F- Granted patents
- 7,181
- Published applications
- 7,964
- Assignees
- 2,266
- Inventors
- 12,009
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 32 | 0 |
| 1977 | 34 | 0 |
| 1978 | 19 | 0 |
| 1979 | 26 | 0 |
| 1980 | 23 | 0 |
| 1981 | 25 | 0 |
| 1982 | 25 | 0 |
| 1983 | 18 | 0 |
| 1984 | 20 | 0 |
| 1985 | 36 | 0 |
| 1986 | 24 | 0 |
| 1987 | 36 | 0 |
| 1988 | 31 | 0 |
| 1989 | 41 | 0 |
| 1990 | 35 | 0 |
| 1991 | 33 | 0 |
| 1992 | 32 | 0 |
| 1993 | 28 | 0 |
| 1994 | 33 | 0 |
| 1995 | 56 | 0 |
| 1996 | 52 | 0 |
| 1997 | 46 | 0 |
| 1998 | 74 | 0 |
| 1999 | 57 | 0 |
| 2000 | 52 | 0 |
| 2001 | 74 | 11 |
| 2002 | 73 | 79 |
| 2003 | 66 | 98 |
| 2004 | 73 | 120 |
| 2005 | 88 | 129 |
| 2006 | 126 | 112 |
| 2007 | 104 | 146 |
| 2008 | 72 | 162 |
| 2009 | 78 | 192 |
| 2010 | 120 | 220 |
| 2011 | 145 | 190 |
| 2012 | 130 | 246 |
| 2013 | 156 | 402 |
| 2014 | 223 | 578 |
| 2015 | 282 | 580 |
| 2016 | 418 | 482 |
| 2017 | 514 | 528 |
| 2018 | 525 | 606 |
| 2019 | 529 | 512 |
| 2020 | 473 | 475 |
| 2021 | 434 | 475 |
| 2022 | 425 | 414 |
| 2023 | 344 | 365 |
| 2024 | 377 | 352 |
| 2025 | 294 | 294 |
| 2026 | 150 | 196 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- H01F 38/14Inductive couplings4,219
- H01F 38/20Instruments transformers654
- H01F 38/12Ignition605
- H01F 38/48Common mode inductor for reducing or eliminating common mode noise on parallel457
- H01F 38/08High-leakage transformers or inductances332
- H01F 38/18Rotary transformers282
- H01F 38/02Adaptations of transformers or inductances for specific applications or functions: for non-linear246
- H01F 38/50Transformers for galvanic isolation246
All 14 subgroupsShow fewer
- H01F 38/42Flyback transformers171
- H01F 2038/006Matrix transformer consisting of several interconnected individual transformers working as a wholeIndexing code103
- H01F 2038/003High frequency transformer for microwave ovenIndexing code23
- H01F 38/16Cascade transformers20
- H01F 38/44Traction transformers for powering electric vehicles0
- H01F 38/46Inductors specially adapted for electric vehicles0
Recent patents
- Coil device6 Oct 2026US 12,755,895 B2TDK Corporation
- Variable magnetic layer for wireless charging6 Oct 2026US 12,755,898 B23M Innovative Properties Company
- Segmented wireless power transfer29 Sep 2026US 12,749,920 B2The Regents of the University of Michigan
- Rotor for an externally excited synchronous machine29 Sep 2026US 12,749,951 B2Mahle International GmbH
- Isolator22 Sep 2026US 12,744,153 B2Kabushiki Kaisha Toshiba
- Choke for a multi-conductor system8 Oct 2026US 2026/0311924 A1TDK Electronics Co., Ltd.
- Plug-in connection part for inductively transmitting energy and/or signals in a potentially explosive environment, connecting device and measuring system8 Oct 2026US 2026/0311930 A1Knick Elektronische Messgeräte GmbH & Co. KG
- Magnetic component1 Oct 2026US 2026/0302046 A1Delta Electronics, Inc.
- Transformer and electrical device with transformer1 Oct 2026US 2026/0302058 A1
- Wireless exciter system, a motor and a mobility device having the same1 Oct 2026US 2026/0302895 A1Chalmers University of Technology
Most cited
By later US patents
- Surgical sterilizer with integrated battery charging device1,015US 8,258,745 B2Syntheon, LLC · 2012
- Wireless non-radiative energy transfer952US 7,741,734 B2Massachusetts Institute of Technology · 2010
- Alignment independent and self aligning inductive power transfer system812US 6,803,744 B12004
- Planar resonator for wireless power transfer610US 6,960,968 B2Koninklijke Philips Electronics N. V. · 2005
- Inductive power source and charging system591US 7,952,322 B2Mojo Mobility, Inc. · 2011