Power Supply Load Detection Without Shunt Resistors in Standby

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Solution Overview

Problem

Existing systems fail to effectively reduce standby power consumption in electronic devices, often relying on shunt resistors that struggle with low current detection and result in inefficient power management, leading to increased global carbon emissions and reduced device longevity.

Innovation Solution

A control unit with a separate power source that uses a load detector to determine the presence or absence of a load without shunt resistors, activating or deactivating the load power source accordingly, and employing photovoltaic drivers in an anti-parallel configuration to manage power efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If shunt resistors are used for load detection, then load presence can be detected, but power consumption increases and detection precision deteriorates at low currents

Engineering Contradiction:
Improveload detection precisionVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts the load detection function from the traditional shunt resistor approach and implements it through a microcontroller unit that measures voltage across capacitors. This separates the detection mechanism from the power-consuming resistive element, enabling accurate load detection without continuous power consumption.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses the existing capacitor voltage in the power supply circuit to detect load presence, rather than introducing a separate detection component. The voltage across the capacitor naturally reflects the load state, allowing the system to self-diagnose without additional power-consuming sensors.

Inventive Principle:
Principle #25Self-service

2Reliability

If the load power source remains active during standby, then device readiness is maintained, but standby power consumption increases

Engineering Contradiction:
Improvedevice readinessVSAvoidstandby power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent implements dynamic power management where the load power source automatically transitions between active and standby states based on real-time load detection. The system adapts its power consumption level according to actual operational needs, switching to ultra-low power mode when no load is detected while maintaining quick restart capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary load detection before fully activating the power source. The microcontroller continuously monitors capacitor voltage to detect load presence, and only activates the full power source when actually needed, preventing unnecessary power consumption during true standby periods.

Inventive Principle:
Principle #10Preliminary action

3Speed

If continuous power monitoring is implemented, then load changes are detected promptly, but power consumption increases

Engineering Contradiction:
Improveload detection speedVSAvoidmonitoring power consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

Instead of continuous monitoring, the patent implements periodic sampling of capacitor voltage at strategically chosen moments in the power cycle. The microcontroller measures voltage at specific intervals and uses this periodic data to infer load presence, achieving timely detection while minimizing the duration and frequency of active measurement periods.

Inventive Principle:
Principle #19Periodic action

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

This approach significantly reduces standby power consumption, decreases carbon emissions, enhances device efficiency, and prolongs electronic device longevity by accurately detecting load presence or absence and managing power accordingly.

Implementation Method 1

the control unit power source comprises a first photovoltaic driver (e.g., a photovoltaic MOSFET driver) and a second photovoltaic driver mounted in an anti-parallel configuration, and rectifier components connected to at least one of the photovoltaic drivers to generate power for the control unit

Methodology Applied
Scientific EffectPhotovoltaic Effect: Photovoltaic Effect

Implementation Method 2

The load power source, when caused by the control unit to discharge electricity to the load upon the detection of the load, feeds the load by supplying a direct current voltage to generate output, which is galvanically isolated from the input

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP4404450A1Power supply having ultra low standby power consumption
Publication Date: 2024.07.24 DATALOGIC IP TECH
  • EP4404450A1 patent drawingFigure 1
  • EP4404450A1 patent drawingFigure 2
  • EP4404450A1 patent drawingFigure 3

AI summary

The technology described herein relates to methods and systems for reducing standby power consumed by electronic devices. A control unit is powered by a control unit power source. The control unit power source, in some embodiments, comprises a first photovoltaic driver and a second photovoltaic driver mounted in an anti-parallel configuration. In other embodiments, the control unit power source is a battery (e.g., a rechargeable battery). In addition, the control unit can cause a load power source to switch off upon detection of an absence of a load (e.g., by using the load detector) without the use of a shunt resistor. The control unit also causes the load power source to discharge electricity to the load upon detection of the load.