H01F 38/34
Combined voltage and current transformers
H01F38/34 (Combined voltage and current transformers) appears on 21 US grants and 18 published applications in this corpus.
Search patents in H01F- Granted patents
- 21
- Published applications
- 18
- Assignees
- 20
- Inventors
- 67
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 1 | 0 |
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 2 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 1 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 1 | 0 |
| 1996 | 0 | 0 |
| 1997 | 1 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 1 |
| 2012 | 0 | 2 |
| 2013 | 0 | 1 |
| 2014 | 2 | 2 |
| 2015 | 1 | 0 |
| 2016 | 1 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 1 |
| 2019 | 0 | 1 |
| 2020 | 1 | 2 |
| 2021 | 0 | 2 |
| 2022 | 1 | 2 |
| 2023 | 1 | 2 |
| 2024 | 1 | 0 |
| 2025 | 1 | 1 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- HV apparatus and a method of manufacturing such apparatus15 Sep 2026US 12,738,415 B2Hitachi Energy Ltd
- Instrument transformer and method to isolate parts2 Jun 2026US 12,646,650 B2HSP Hochspannungsgeräte GmbH
- High voltage instrument transformer and method for partial discharge recognition11 Mar 2025US 12,249,455 B2HSP Hochspannungsgeräte GmbH
- Device and method for compensating for a vibration and/or a material stress4 Jun 2024US 12,000,451 B2Siemens Energy Global GmbH & Co. KG
- HV apparatus and a method of manufacturing such apparatus14 Mar 2023US 11,605,501 B2Hitachi Energy Switzerland AG
- Nterface test device with low power switch26 Feb 2026US 2026/0056236 A1
- Coated active component in a high-voltage device and method for increasing the di-electric strength23 Oct 2025US 2025/0327841 A1HSP Hochspannungsgeräte GmbH
- High voltage instrument transformer and method for partial discharge recognition14 Sep 2023US 2023/0290566 A1Siemens Energy Global GmbH & Co. KG
- Hv apparatus and a method of manufacturing such apparatus13 Jul 2023US 2023/0223189 A1Hitachi Energy Switzerland AG
- Instrument transformer and method to isolate parts6 Oct 2022US 2022/0319770 A1Siemens Energy Global GmbH & Co. KG
Most cited
By later US patents
- Combined current and voltage measuring apparatus55US 4,074,193 ASiemens Aktiengesellschaft · 1978
- Measuring transformer for high-voltage switch-gear with metal encapsulation39US 4,354,154 ASiemens Aktiengesellschaft · 1982
- High voltage measurement transformer for suspension from a high voltage switching apparatus34US 4,808,910 ASprecher & Schuh AG · 1989
- Combined current and voltage transformer for a metal-enclosed gas-insulated high-voltage switching station15US 5,432,438 AAsea Brown Boverti Ltd. · 1995
- Combined high-voltage current and voltage transformer10US 4,731,599 AMWB Messwandler-Bau AG · 1988