Multi-Load Circuit Control Using Single Galvanic Isolation Unit
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Solution Overview
Problem
The existing methods for controlling electrical loads in household appliances, such as washing machines and dishwashers, require high outlay due to the need for galvanic isolation between control modules in the SELV/PELV range and loads in the FELV range, leading to increased costs, weight, and installation space.
Innovation Solution
A circuit arrangement that includes a main control module in a first voltage range generating control data, a galvanic isolation unit for transferring data to a second voltage range, and auxiliary control modules with programmable outputs to efficiently control loads, utilizing LED drivers or GPIO expanders to operate loads and reduce the number of isolation units needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If galvanic isolation units are used for each control channel between SELV/PELV control module and FELV loads, then safety and galvanic isolation are ensured, but cost, weight, and installation space increase significantly
Solution Approach 1:
The patent combines multiple control channels into a single galvanic isolation unit that can handle multiple loads simultaneously. Instead of using separate isolation units for each load, the invention integrates multiple control signals through one isolation barrier, thereby reducing the total number of isolation components while maintaining safety requirements.
Solution Approach 2:
The auxiliary control module serves multiple functions: it receives control signals from the SELV/PELV range, performs galvanic isolation, and distributes control signals to multiple FELV loads. This multi-functional approach eliminates the need for separate isolation units for each load, reducing overall system complexity and component count.
2Ease of operation
If multiple galvanic isolation units are deployed for controlling multiple loads, then each load can be independently and safely controlled, but the PCB area and installation space required increase
Solution Approach 1:
Multiple control channels are merged into a single galvanic isolation unit, allowing independent control of multiple loads through one isolation component. This integration significantly reduces the PCB area required compared to using separate isolation units for each load.
Solution Approach 2:
The patent implements a hierarchical control structure where the auxiliary control module nests multiple control functions within a single galvanic isolation framework. This nested architecture allows independent load control while minimizing the physical space required on the PCB.
3Measurement precision
If separate control modules are used for each load in different voltage ranges, then precise control is achieved, but the overall system cost and weight increase
Solution Approach 1:
The patent merges multiple control functions into a single auxiliary control module that operates in the FELV range and receives signals from the SELV/PELV range through galvanic isolation. This consolidated approach maintains precise control for each load while significantly reducing system weight compared to using separate control modules for each load.
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 solution enables efficient, cost-effective, and space-saving control of multiple electrical loads across different voltage ranges by using auxiliary control modules to identify and control loads via a single galvanic isolation unit, reducing the number of isolation elements and PCB area required.
Implementation Method 1
a galvanic isolation unit configured to transfer the control data via a galvanically isolated connection from the first voltage range to the second voltage range
Implementation Method 2
a light-emitting diode driver configured to operate a corresponding plurality of LED arrangements via said plurality of control outputs
Data Source
AI summary
A circuit arrangement for controlling a plurality of loads of an electrical appliance has a main control module, arranged in a first voltage range and configured to generate control data for controlling a plurality of loads, which are arranged in a second voltage range. A galvanic isolation unit transfers the control data via a galvanically isolated connection from the first voltage range to the second voltage range. At least one auxiliary control module has a plurality of control outputs for the loads and an LED driver for operating a corresponding plurality of LED arrangements via the of control outputs, and/or a general-purpose input/output expansion circuit with programmable control outputs. Based on the control data, the auxiliary control module identifies a first control output for controlling the first load and causes the first load to be controlled via the first control output.