H01F 38/305
With toroidal magnetic core
Official title: {with toroidal magnetic core}
H01F38/305 (With toroidal magnetic core) appears on 112 US grants and 107 published applications in this corpus.
Search patents in H01F- Granted patents
- 112
- Published applications
- 107
- Assignees
- 95
- Inventors
- 268
- Latest grant
- 7 Apr 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 2 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 2 | 0 |
| 1989 | 3 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 3 | 0 |
| 1994 | 1 | 0 |
| 1995 | 5 | 0 |
| 1996 | 5 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 1 |
| 2008 | 0 | 2 |
| 2009 | 1 | 0 |
| 2010 | 2 | 7 |
| 2011 | 2 | 1 |
| 2012 | 1 | 3 |
| 2013 | 3 | 4 |
| 2014 | 1 | 3 |
| 2015 | 3 | 7 |
| 2016 | 5 | 10 |
| 2017 | 6 | 5 |
| 2018 | 4 | 9 |
| 2019 | 4 | 12 |
| 2020 | 9 | 12 |
| 2021 | 7 | 5 |
| 2022 | 5 | 4 |
| 2023 | 10 | 10 |
| 2024 | 6 | 7 |
| 2025 | 5 | 2 |
| 2026 | 1 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Spiral core current transformer for energy harvesting applications7 Apr 2026US 12,597,558 B2S&C Electric Company
- Magnetic core winder for powerline-mounted devices16 Dec 2025US 12,500,032 B2Schweitzer Engineering Laboratories, Inc.
- Single package, dual current transformer for load and residual current measurement7 Oct 2025US 12,437,916 B2Vertiv Corporation
- Compact outdoor open-close type current transformer22 Apr 2025US 12,283,410 B2Jiangyin Spark Electronic Technology Co., Ltd.
- Electric current sensor4 Mar 2025US 12,241,915 B2Tokin Corporation
- System on sensor electrical protective device30 Jul 2026US 2026/0221365 A1Schneider Electric USA, Inc.
- Mitigation of differential current transformer cross-talk2 Apr 2026US 2026/0094760 A1Schneider Electric USA, Inc.
- Enhanced differential sensor winding pattern2 Apr 2026US 2026/0094763 A1Schneider Electric USA, Inc.
- Ct energy extraction device20 Mar 2025US 2025/0095899 A1Electric Power Research Institute of Yunnan Power Grid Co., Ltd
- Apparatus and method for embedding current measurement and ringing suppression in multichip modules6 Mar 2025US 2025/0076346 A1The Board of Trustees of The University of Alabama
Most cited
By later US patents
- Coaxial current sensors76US 5,066,904 AGeneral Electric Company · 1991
- Current transformer using a laminated toroidal core structure and a lead frame66US 5,430,613 AEaton Corporation · 1995
- Split core current transformer having an interleaved joint and hinge structure54US 4,048,605 ASangamo Electric Company · 1977
- Current transformer for measuring instruments46US 4,513,274 ALGZ Landis & Gyr Zug AG · 1985
- Wire wound core42US 5,235,488 ABrett Products, Inc. · 1993