Air-core inductor assembly
US-2020388436-A1 · Dec 10, 2020 · US
Current transformers
Current transformers · Cooperative Patent Classification (CPC)
Electric circuits, power, telecommunications, and semiconductors.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | H01F38/28 |
| Official title | Current transformers |
| Display label | Current transformers |
| Total patents | 110 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is declining.
| Year | Patents |
|---|---|
| 2015 | 12 |
| 2016 | 8 |
| 2017 | 10 |
| 2018 | 15 |
| 2019 | 8 |
| 2020 | 9 |
| 2021 | 10 |
| 2022 | 9 |
| 2023 | 11 |
| 2024 | 13 |
| 2025 | 5 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
System and method for energy sensing and harvesting with fault detection
US-2020241051-A1 · Jul 30, 2020 · US
Power conversion device and contactless power supply system
US-10686332-B2 · Jun 16, 2020 · US
Current transformer, protection device and electrical circuit breaker including such a transformer
US-2020176166-A1 · Jun 4, 2020 · US
Dual feeder systems having current transformers
US-2020141982-A1 · May 7, 2020 · US
Current measuring device protected against electrical surges when opening the circuit
US-10591514-B2 · Mar 17, 2020 · US
Device and method for harvesting energy from a power line magnetic field
US-2020052488-A1 · Feb 13, 2020 · US
Trip control circuit for circuit breaker
US-10483751-B2 · Nov 19, 2019 · US
Current transformer
US-10340079-B2 · Jul 2, 2019 · US
Core for current transformer
US-2019180932-A1 · Jun 13, 2019 · US
Dynamic impedance system for an increased range of operation of an instrument transformer
US-10298208-B1 · May 21, 2019 · US
Current transformer and direct current source based on current transformer
US-10276301-B2 · Apr 30, 2019 · US
Self-powered wireless energy sensor for efficient building management
US-2019113546-A1 · Apr 18, 2019 · US
A current measuring device protected against electrical surges when opening the circuit
US-2019033345-A1 · Jan 31, 2019 · US
Power conversion device and contactless power supply system
US-2019027964-A1 · Jan 24, 2019 · US
System and method for tuning transformers
US-10132848-B2 · Nov 20, 2018 · US
Multi-winding high sensitivity current transformer
US-10090093-B2 · Oct 2, 2018 · US
Current converter with interchangeable head
US-10083787-B1 · Sep 25, 2018 · US
Current converter with interchangeable head
US-2018261372-A1 · Sep 13, 2018 · US
System and method for tuning transformers
US-10060962-B2 · Aug 28, 2018 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC H01F38/28?
- CPC H01F38/28 is the Cooperative Patent Classification code for “Current transformers.”
- How many patents are filed under CPC H01F38/28 (Current transformers)?
- Our database includes 110 publications tagged with this CPC code.
- Is patent activity under CPC H01F38/28 growing?
- Publication counts under this code: 13 in 2024 vs 5 in 2025 (latest complete years).