HVAC controller

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing HVAC controllers face compatibility issues due to diverse system loads and configurations, leading to inefficiencies in power stealing circuitry, particularly when operating with low voltage or zero current but high voltage loads, such as dry contacts, which can result in unreliable operation and increased sensitivity to power fluctuations.

Innovation Solution

A universal AC power circuit with integrated power stealing and isolation transformer, capable of providing power to HVAC components across various systems, including low voltage and high voltage loads, by using a mode switch to disable power stealing when necessary and employing a dual channel circuit for efficient power management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If power stealing circuitry is used to draw power from HVAC loads, then the controller can operate without external power sources, but the circuitry becomes incompatible with certain HVAC system configurations and loads

Engineering Contradiction:

Improvecompatibility with HVAC systemsVSAvoidreliable operation

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically switches between power stealing mode and universal AC power mode based on system conditions. A mode switch component enables the controller to adapt its power acquisition method in real-time, transitioning from power stealing circuitry to universal AC power circuit when incompatibility is detected, thereby maintaining both versatility and reliable operation across different HVAC configurations

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the power supply by switching between different power acquisition modes. When power stealing proves incompatible with certain HVAC loads, the system alters its power parameters by activating the universal AC power circuit, which operates with different voltage and current characteristics suitable for diverse HVAC system types

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If power stealing circuitry is used to operate components, then energy efficiency is improved, but the controller becomes sensitive to power fluctuations and incompatible with diverse HVAC loads

Engineering Contradiction:

Improveenergy efficiencyVSAvoidcompatibility with HVAC loads

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system incorporates a universal AC power circuit that can serve multiple HVAC load types and configurations, making the power supply universally compatible. This multi-functional power circuit works alongside power stealing circuitry, allowing the system to maintain energy efficiency with power stealing when appropriate, while switching to universal AC power when compatibility with diverse HVAC loads is required

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The mode switch acts as an intermediary component that mediates between power stealing circuitry and universal AC power circuit. It monitors system conditions and selectively activates the appropriate power source, enabling the system to balance energy efficiency with compatibility across different HVAC load configurations

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a single power circuit design is used, then device complexity is reduced, but the controller cannot accommodate diverse HVAC system configurations

Engineering Contradiction:

Improvecircuit design complexityVSAvoidaccommodation of HVAC configurations

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The power supply system is segmented into distinct functional modules: power stealing circuitry, universal AC power circuit, and mode switch. This segmentation allows each component to be independently designed and optimized, maintaining relatively simple individual circuit designs while achieving complex overall functionality through modular integration that accommodates diverse HVAC configurations

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Ensures reliable operation of HVAC controllers across diverse systems, reduces sensitivity to power fluctuations, and allows for accurate load detection and configuration, enhancing setup simplicity and energy efficiency.

Implementation Method 1

an isolation transformer connected to the signal conditioner and driver

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS12553639B2HVAC controller

Publication Date: 2026.02.17 RESIDEO LLC

AI summary

A controller for an environmental control system, e.g., an HVAC system, that includes a power circuit for providing power to some components of the controller across a variety of HVAC systems. The HVAC controller of this disclosure may include components with power stealing circuitry to run components. However, because the diversity of HVAC system loads and configurations, some power stealing circuitry may not function as desired to draw the power for operation in some systems. The universal AC power circuit included in the HVAC controller of this disclosure may provide power to components of the HVAC controller when the power stealing circuitry may be incompatible with certain HVAC systems. In this manner, the universal AC power circuit may allow the HVAC controller of this disclosure to be compatible with and operate to control a wide variety of environmental control systems.