Household appliance and method of operating a household appliance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrically operated household appliances face issues with high starting and inrush currents that can damage motors and other components, and the use of additional resistors to limit these currents is costly, space-consuming, and susceptible to vibration.
Innovation Solution
The solution involves using the second functional unit of the appliance, which provides a secondary function, to also act as a current limiting element, eliminating the need for additional resistors by integrating the current limiting function into the appliance's pre-circuit, and employing a switching unit to temporarily deactivate the current limiting element during normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional resistors are used to limit starting and inrush currents, then current damage to motor and electrical components is prevented, but device complexity, cost, and installation space increase
Solution Approach 1:
The second functional unit is designed to serve dual purposes: performing its intended appliance function and simultaneously acting as a current limiting element during motor startup. This multi-functionality eliminates the need for separate current limiting resistors, reducing device complexity while maintaining protection against current damage.
2Reliability
If additional resistors are connected in series to limit starting current, then current peaks are reduced, but installation space and manufacturing costs increase
Solution Approach 1:
The heating element performs dual functions: providing heating capability for the appliance and serving as a current limiting element during motor startup. This eliminates the need for separate current limiting resistors, reducing both manufacturing costs and installation space while maintaining protection against inrush current.
3Reliability
If the current limiting element remains active during normal operation, then continuous current protection is provided, but energy efficiency is reduced
Solution Approach 1:
The circuit design dynamically switches the current limiting element into and out of the circuit based on operational requirements. During motor startup, the heating element limits current; during normal operation, it is bypassed to allow efficient current flow. This dynamic configuration provides current protection when needed while maintaining energy efficiency during continuous operation.
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 reduces the risk of component damage, saves costs and space, enhances robustness against vibrations, and allows for efficient energy use by decoupling the functional units when not needed.
Implementation Method 1
the pre-circuit has a current limiting element for limiting a current (when the operating device is switched on or started)
Implementation Method 2
employing a switching unit to temporarily deactivate the current limiting element during normal operation
Data Source
AI summary
The invention relates to a household appliance (1) comprising a movable first functional unit (10) for providing a first appliance function to a user, an electrical second functional unit (20) for providing a second appliance function to the user, and an operating device (11) for powering the first functional unit (10), comprising an electric motor (12), a connection (13) for supplying power to the electric motor (12), and a pre-circuit (30) connected between the connection (13) and the electric motor (12), wherein the pre-circuit (30) comprises a current limiting element (31) for limiting a current (200). The invention also relates to a method (100) for operating a household appliance (1).