H01F 7/1805
Circuit arrangements for holding the operation of electromagnets or for holding the
Official title: {Circuit arrangements for holding the operation of electromagnets or for holding the armature in attracted position with reduced energising current (for holding relay armature in attracted position with reduced energising current H01H47/04; quick energising of electro-dynamic machines H02P9/08; for quickly de-energising of dynamo-electric generators H02P9/123)}
H01F7/1805 (Circuit arrangements for holding the operation of electromagnets or for holding the) appears on 276 US grants and 223 published applications in this corpus.
Search patents in H01F- Granted patents
- 276
- Published applications
- 223
- Assignees
- 189
- Inventors
- 661
- Latest grant
- 25 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 2 | 0 |
| 1978 | 4 | 0 |
| 1979 | 2 | 0 |
| 1980 | 2 | 0 |
| 1981 | 4 | 0 |
| 1982 | 10 | 0 |
| 1983 | 2 | 0 |
| 1984 | 4 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 5 | 0 |
| 1988 | 1 | 0 |
| 1989 | 2 | 0 |
| 1990 | 3 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 4 | 0 |
| 1995 | 7 | 0 |
| 1996 | 5 | 0 |
| 1997 | 3 | 0 |
| 1998 | 9 | 0 |
| 1999 | 7 | 0 |
| 2000 | 10 | 0 |
| 2001 | 7 | 0 |
| 2002 | 4 | 0 |
| 2003 | 2 | 3 |
| 2004 | 3 | 9 |
| 2005 | 5 | 14 |
| 2006 | 9 | 7 |
| 2007 | 4 | 8 |
| 2008 | 5 | 11 |
| 2009 | 7 | 21 |
| 2010 | 8 | 8 |
| 2011 | 9 | 10 |
| 2012 | 6 | 10 |
| 2013 | 8 | 11 |
| 2014 | 8 | 4 |
| 2015 | 9 | 10 |
| 2016 | 5 | 11 |
| 2017 | 7 | 11 |
| 2018 | 7 | 8 |
| 2019 | 12 | 13 |
| 2020 | 10 | 12 |
| 2021 | 13 | 10 |
| 2022 | 11 | 7 |
| 2023 | 6 | 6 |
| 2024 | 9 | 9 |
| 2025 | 5 | 4 |
| 2026 | 4 | 6 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- H01F 7/1816Making use of an energy accumulator78
- H01F 7/1811Demagnetising upon switching off, removing residual magnetism69
- H01F 7/1833By changing number of parallel-connected turns or windings14
- H01F 7/1838By switching-in or -out impedance13
- H01F 7/1827By changing number of serially-connected turns or windings8
Recent patents
- Switch arrangement and method for operating a switch arrangement25 Aug 2026US 12,718,999 B2Siemens Aktiengesellschaft
- Detecting pickup and dropout of solenoid valve26 May 2026US 12,638,102 B2Automatic Switch Company
- Solenoid assembly with included constant-current controller circuit3 Mar 2026US 12,567,526 B2Hanchett Entry Systems, Inc.
- Method and circuitry for controlling discharge of a solenoid valve6 Jan 2026US 12,518,901 B2Scania CV AB
- Load drive device and method for controlling electronic control device21 Oct 2025US 12,451,281 B2Hitachi Astemo, Ltd.
- Solenoid actuator efficiency optimization13 Aug 2026US 2026/0237547 A1Analog Devices International Unlimited Company
- Circuit and method for driving an inductive load with reduced power loss13 Aug 2026US 2026/0237548 A1
- Valve control for controlling a solenoid valve, valve arrangement and method for operating a solenoid valve23 Apr 2026US 2026/0110369 A1Festo AG & Co.
- Electric door lock driver based on a current pulse generator and a switched mode current source with load-dependent output5 Mar 2026US 2026/0066165 A1Akiles Technologies, S.L.
- Method and system for closed-loop feed forward control of actuation of a solenoid5 Feb 2026US 2026/0038723 A1
Most cited
By later US patents
- Method and apparatus for controlling the current through a magnetic coil76US 5,442,515 AClark Equipment Company · 1995
- Fuel injection valve drive control apparatus64US 5,574,617 AHonda Giken Kogyo Kabushiki Kaisha · 1996
- Control circuit for solenoid valve60US 5,632,468 AAquatec Water Systems, Inc. · 1997
- Electrically driven bistable mechanical actuator56US 6,836,201 B1Raytheon Company · 2004
- System and method for operating high speed solenoid actuated devices53US 5,381,297 ASiemens Automotive Corporation · 1995