Stand-by Circuit Monostable Switch Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing stand-by circuit solutions for household appliances continue to consume energy even in the stand-by state due to components like the control unit and AC-DC converter remaining active, leading to inefficiencies and increased energy waste, especially after power blackouts where appliances resume operation before returning to stand-by.

Innovation Solution

A stand-by circuit utilizing a monostable switch and an energizer module to disconnect the AC-DC converter from power during stand-by, combined with a wake-up switch and a resistive-capacitive network to maintain the appliance's state during blackouts, ensuring minimal power consumption and efficient reactivation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a switch is arranged between the AC-DC converter and on-board electronics to enable stand-by state, then energy consumption during stand-by is reduced, but the control unit and AC-DC converter still consume power leading to non-zero energy waste

Engineering Contradiction:
Improveenergy consumption in stand-by stateVSAvoidcontrol circuit complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the power control into two distinct switches: a first switch (S1) that disconnects the AC-DC converter from the mains, and a second switch (S2) that disconnects the downstream electronic circuits from the converter output. This segmentation allows the AC-DC converter to be turned off completely during stand-by, eliminating its power consumption while maintaining simple control through the microcontroller.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the appliance resumes operating state after a blackout before returning to stand-by, then the control unit can read stored state information, but energy is wasted by entering operating state unnecessarily

Engineering Contradiction:
Improvestate restoration after blackoutVSAvoidenergy waste during state restoration
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements preliminary action by having the wake-up switch (S3) automatically close after a predetermined time interval following a blackout. This automatic wake-up mechanism ensures the appliance restores its previous state without requiring manual intervention or unnecessary entry into full operating mode, thereby preventing energy waste while maintaining reliability through the non-volatile memory (U1) that preserves state information during power interruptions.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If the monostable switch is used to disconnect power mains from AC-DC converter, then near-zero power consumption is achieved in stand-by, but the switch requires precise control to prevent unintended switching

Engineering Contradiction:
Improvepower consumption in stand-by modeVSAvoidswitch control stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent uses an intermediary approach by implementing a dedicated energizer module that provides controlled current to the monostable switch's control terminal. This intermediary control mechanism, combined with the wake-up switch that automatically closes after a predetermined time, prevents unintended switching while maintaining near-zero power consumption. The resistive-capacitive network also acts as an intermediary to manage the switch's stable and unstable states reliably.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The solution achieves near-zero power consumption in stand-by mode and reduces energy waste by allowing appliances to resume their previous state directly after a blackout without entering the operating state, thereby minimizing energy usage.

Implementation Method 1

a stand-by circuit (1) fitted with a monostable switch (3) arranged between an alternating power mains and an AC-DC converter (4)

Methodology Applied
Scientific EffectMonostable switch: Relay

Implementation Method 2

an energizer module (5) which, by energizing a control branch (305) of the monostable switch (3), comprised between two control terminals (303, 304), holds it in the unstable position

Methodology Applied
Scientific EffectEnergizing control branch: Electromagnet

Implementation Method 3

a wake-up switch (6) that, when closed, allows energizing the control branch (305) of the monostable switch (3) when the household appliance is in stand-by state

Methodology Applied
Scientific EffectWake-up switch: Relay

Data Source

PatentEP2458707B1Stand-by circuit for household appliances
Publication Date: 2019.02.13 WHIRLPOOL EMEA SPA
  • EP2458707B1 patent drawingFigure 1
  • EP2458707B1 patent drawingFigure 2
  • EP2458707B1 patent drawingFigure 3

AI summary

The present invention relates to a stand-by circuit (1) comprising a first input (100) for receiving a phase of the mains supply, a second input (101) for receiving a stand-by signal, a monostable switch (3), an AC-DC converter (4), wherein said switch (3) is adapted to connect said first input (100) electrically to said AC-DC converter (4) when said switch (3) is suitably energized, further comprising an energizer module (5) adapted to energize said switch (3) when at the output of said converter (4) there is a voltage other than the ground voltage, said energizer module (5) being further adapted to interrupt its energizing action upon said switch (3) if it receives a suitable stand-by signal at said second input (101). Said stand-by circuit (1) further comprises a switch (6) which allows, when closed, to energize said switch (3).