DCT

3:26-cv-00072

Electrasense Tech LLC v. Legrand North America LLC

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:26-cv-00072, N.D. Tex., 01/12/2026
  • Venue Allegations: Plaintiff alleges venue is proper in the Northern District of Texas because Defendant maintains a regular and established place of business in Richardson, Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s USB wall outlets infringe a patent related to dynamically adjusting DC output voltage based on the requirements of a connected electronic device.
  • Technical Context: The technology addresses the need for smart power-charging solutions in wall outlets that can adapt to the varying power requirements of modern electronics, such as smartphones and tablets, to improve charging efficiency and compatibility.
  • Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

Date Event
2015-06-18 ’876 Patent Priority Date
2017-11-07 ’876 Patent Issue Date
2026-01-12 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,812,876 - *Wall socket with load detecting circuit*

The Invention Explained

  • Problem Addressed: The patent's background section notes that conventional USB wall sockets provide only a fixed output voltage, which is insufficient for the varied charging requirements of modern devices and leads to unnecessary energy loss during standby states (’876 Patent, col. 1:21-27).
  • The Patented Solution: The invention is a wall socket incorporating a "load detecting circuit" designed to solve this problem. When an electronic device is connected, the circuit receives an "identification signal" from the device. Based on this signal, the circuit generates a control signal that instructs a power converting circuit to adjust the DC output voltage to a level appropriate for that specific device, selecting from a "plurality of different voltage levels" (’876 Patent, Abstract; col. 4:12-20). The high-level block diagram in Figure 2 illustrates the relationship between the power converting circuit (220), the load detecting circuit (240), and the output terminal (290) (’876 Patent, FIG. 2).
  • Technical Importance: This approach allows a single wall outlet to dynamically adapt its power output, ensuring compatibility with a wide range of electronic devices and enhancing power management efficiency (Compl. ¶12).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶15).
  • The essential elements of independent claim 1 include:
    • A socket housing, an input terminal, and an output terminal.
    • A power converting circuit that converts an input voltage to a DC output voltage based on a control signal.
    • A load detecting circuit that receives an "identification signal" from a connected electronic device.
    • The load detecting circuit outputs the control signal "according to the identification signal to adjust a voltage level of the dc output voltage," with the level being "selected from a plurality of different voltage levels."
    • The voltage level from the same output pin "varies according to the identification signal."
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

The "Accused Products" include the Legrand Radiant 65W USB Outlet, Spec Grade 30W USB Outlet, 65W Hospital Grade USB Outlet, 65W Commercial USB Outlet, radiant 30W USB Outlet, and Adorne 30W USB Outlet (Compl. ¶14).

Functionality and Market Context

The complaint alleges these are wall outlets that provide USB charging functionality (Compl. ¶8, 14). To support venue allegations, the complaint includes a screenshot from the Dallas Central Appraisal District website showing Defendant as the owner of business property at an address in Richardson, Texas (Compl. p. 2). The complaint does not provide sufficient detail for analysis of the specific internal circuitry or operational protocols of the Accused Products, instead asserting that they possess the "functionality claimed" in the patent-in-suit (Compl. ¶8).

IV. Analysis of Infringement Allegations

The complaint references an "exemplary claim chart" in Exhibit 1 to evidence infringement by the Accused Products (Compl. ¶15). As this exhibit was not attached to the publicly filed complaint, the following summarizes the narrative infringement theory.

The complaint alleges that the Accused Products infringe the ’876 Patent by incorporating technology that performs the patented function (Compl. ¶14). The core of the allegation is that the Accused Products improve upon prior art fixed-voltage chargers by "integrating a load detection circuit that identifies the voltage requirements of an electronic device and dynamically adjusts the DC output" (Compl. ¶12). This allegation suggests the plaintiff's theory is that the Accused Products, likely by implementing modern charging standards such as USB Power Delivery (USB-PD), necessarily practice the elements of the asserted claims, including receiving an "identification signal" and adjusting voltage accordingly.

Identified Points of Contention

  • Scope Questions: A central dispute may concern whether the implementation of an industry-standard communication protocol (e.g., USB-PD) within an integrated controller chip constitutes the claimed "load detecting circuit." The question for the court may be whether this term requires a structurally distinct component or can be met by distributed functionality within a larger system-on-a-chip.
  • Technical Questions: The complaint does not specify how the Accused Products generate the alleged "identification signal" or how their internal components map to the "load detecting circuit" and "power converting circuit" described in the patent. A key technical question will be what evidence demonstrates that the Accused Products' operation aligns with the specific architecture and signal flow required by the claim language.

V. Key Claim Terms for Construction

"load detecting circuit"

Context and Importance

This term is central to the novelty of the invention. Its construction will be critical, as the infringement analysis will turn on whether the circuitry within the Accused Products, which may be a standard USB controller, meets this definition. Practitioners may focus on this term because Defendant may argue its products contain a single, integrated controller rather than a separate "load detecting circuit."

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The patent functionally defines the circuit as being "configured to receive an identification signal... and output the control signal according to the identification signal to adjust a voltage level" (’876 Patent, col. 8:20-28). This functional description could support a construction that is not limited by a specific physical structure.
  • Evidence for a Narrower Interpretation: The patent’s diagrams consistently depict the "load detecting circuit (240)" as a distinct block, separate from the "power converting circuit (220)" and the "driving circuit (260)" (’876 Patent, FIG. 2, 3, 5). This visual separation could support a narrower construction requiring a structurally distinct or modular element.

"identification signal"

Context and Importance

The nature of this signal defines the input that triggers the claimed voltage adjustment. The dispute will likely focus on whether the complex, multi-step negotiation protocols of modern USB standards qualify as the claimed "identification signal."

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The specification states the signal can be received via various pins associated with different USB standards, including "D+ and D- pins of the USB 2.0... CC1 and CC2 pins of the USB 3.1 type-C" (’876 Patent, col. 4:43-48). This suggests an intent to cover a variety of signaling methods used in the art.
  • Evidence for a Narrower Interpretation: The specification describes the purpose of the signal is to allow the circuit to "determine[] the type of the electronic device or the DC output voltage Vout required by the electronic device" (’876 Patent, col. 6:23-26). This could support a narrower construction requiring the signal to explicitly and directly encode a device type or a specific voltage request, as opposed to being part of a more general-purpose communication handshake.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement under 35 U.S.C. § 271(b), asserting that Defendant encourages infringement by providing "specifications, instructions, manuals, advertisements, marketing materials, and technical assistance" for the Accused Products (Compl. ¶16).

Willful Infringement

The prayer for relief seeks a judgment that Defendant's infringement has been willful (Compl. p. 6, ¶C). The body of the complaint does not, however, allege specific facts supporting pre-suit knowledge of the ’876 Patent.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of definitional scope: Can the term "load detecting circuit," depicted in the patent as a distinct block element, be construed to cover the functionality of a modern, multi-function USB Power Delivery controller chip that is integrated with other power management functions?
  • A second central issue will be one of technical mapping: What evidence will be required to show that the communication protocols used by the Accused Products constitute the "identification signal" as claimed, and how will the Plaintiff demonstrate that the internal architecture of those products performs the specific power conversion and control steps recited in Claim 1?