Bootstrap Voltage Control for Quiet Induction Hob Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Induction hobs with insufficiently charged or slowly charged bootstrap units can produce annoying clicking noises and voltage/current peaks, leading to malfunctions and potential destruction of switching units.

Innovation Solution

A household appliance device with an adjustment unit that dynamically adjusts the supply voltage based on switch driver parameters, utilizing a detection unit and voltage setting unit to ensure faster charging and maintain a constant supply voltage, thereby reducing noise and preventing peaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the bootstrap unit is charged with a standard supply voltage, then the charging process is stable, but the charging speed is slow and noise is generated

Engineering Contradiction:
Improvecharging speedVSAvoidnoise
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the supply voltage to the bootstrap unit adjustable and time-dependent. During startup, the supply voltage is increased to accelerate charging. During normal operation, the voltage is reduced to minimize noise and prevent peaks. This dynamic adjustment resolves the contradiction between fast charging and noise reduction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter (supply voltage) of the bootstrap unit based on operational state. By varying the voltage parameter from a higher startup value to a lower operational value, the system achieves both fast initial charging and quiet steady-state operation, resolving the contradiction between charging speed and noise.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the supply voltage to the switch driver unit is increased to speed up bootstrap charging, then charging is faster, but voltage and current peaks occur causing malfunctions

Engineering Contradiction:
Improvecharging speedVSAvoidfunctional stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the supply voltage based on the charging state and operational phase. High voltage is applied only during the initial charging phase when needed for speed. Once charged, the voltage is reduced to prevent peaks. This temporal separation resolves the contradiction between productivity and reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The supply voltage is applied in a periodic manner: high voltage during startup charging, then switched to normal operating voltage. This periodic action allows fast charging when needed while preventing harmful peaks during continuous operation, resolving the contradiction.

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If the supply voltage is kept constant, then the system is simple to control, but the bootstrap unit charges slowly and noise is generated

Engineering Contradiction:
Improvecontrol simplicityVSAvoidcharging speed
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The control unit automatically detects the operational state and adjusts the supply voltage accordingly without user intervention. During startup, it provides high voltage for fast charging; during normal operation, it reduces voltage to minimize noise. This self-service approach maintains ease of operation while improving charging performance.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3603334B1Domestic appliance device and method for operating a domestic appliance device
Publication Date: 2022.05.11 BSH HAUSGERATE GMBH
  • EP3603334B1 patent drawingFigure 1~2
  • EP3603334B1 patent drawingFigure 3~4

AI summary

The invention relates to a domestic appliance device, in particular a cooking appliance device, comprising at least one switch driver unit (10) provided for supplying at least one switching unit (12), and comprising a bootstrap unit (14) provided for supplying at least one supply voltage (56) for the switch driver unit (10). In order to improve the switching behavior, the domestic appliance device includes at least one adjustment unit (16) provided for adjusting, in at least one operating mode, the supply voltage (56) in accordance with at least one electric characteristic of the switch driver unit (10).