EVSE Handle Button HMI Circuit Using Comparator
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Solution Overview
Problem
Conventional electric vehicle charging systems lack advanced human-machine interface (HMI) functionality, relying on additional components like buttons, keypads, or touch screens, which increases costs and complexity, and do not effectively utilize the existing handle button for user interaction beyond basic charging control.
Innovation Solution
Integration of a new HMI circuit within the EVSE's proximity circuit wiring, utilizing the handle button as an input to provide additional charging-related options and functionalities without requiring dedicated HMI components, by using a comparator circuit to interpret the handle button's state and enable user navigation through charging options displayed on the EVSE.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional HMI components (buttons, keypads, touch screens) are added to provide advanced user interaction, then HMI functionality is improved, but device complexity and cost increase
Solution Approach 1:
The handle button, originally designed solely for mechanical latch release, is enhanced to serve multiple functions by integrating a proximity sensor and HMI circuit. The button now detects both mechanical pressing and proximity approach, enabling it to function as both a physical switch and a contactless input device, thereby providing advanced HMI capabilities without adding separate components
Solution Approach 2:
The existing handle button structure serves its original mechanical function while simultaneously providing HMI input capabilities through integrated sensing. The button's inherent mechanical movement and proximity characteristics are leveraged to generate input signals, allowing the component to serve itself for both latching and user interaction purposes
2Adaptability or versatility
If additional HMI components (buttons, keypads, touch screens) are added to provide advanced user interaction, then HMI functionality is improved, but manufacturing cost increases
Solution Approach 1:
The handle button is redesigned to perform multiple functions - mechanical latch release, contactless proximity detection, and HMI input - eliminating the need for separate buttons, keypads, or touch screens. This multi-functionality reduces component count and manufacturing cost while maintaining advanced HMI capabilities
Solution Approach 2:
The proximity sensor and HMI circuitry are integrated into the existing handle button structure, merging multiple functions into a single component. This consolidation reduces the total number of parts, simplifies assembly, and lowers manufacturing costs compared to implementing separate HMI components
3Adaptability or versatility
If the handle button is used for additional HMI input functions, then HMI versatility is improved, but the reliability of the original latch function may be affected
Solution Approach 1:
The handle button system is segmented into distinct sensing zones and functional circuits - the proximity sensor detects approach without contact, while the mechanical switch detects actual pressing. This segmentation allows the system to differentiate between proximity input and latching input, ensuring that HMI functions do not interfere with the reliability of the original latch mechanism
Solution Approach 2:
The control circuit acts as an intermediary that receives signals from both the proximity sensor and mechanical switch, processes them according to system state, and triggers appropriate responses. This intermediary logic ensures that HMI inputs are properly interpreted and that the latch function remains reliable by only activating release when both proximity is detected and mechanical pressing occurs
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
Enhances the EVSE's HMI capabilities with existing components, allowing users to select and navigate charging options using the handle button, reducing costs and complexity while maintaining standard EVSE functionality, and enabling contextual inputs for charging settings like time and delay without additional hardware.
Implementation Method 1
A comparator circuit output indicating a state of the handle button when the current source is activated by the control input
Data Source
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AI summary
An electric vehicle supply equipment includes EVSE control electronics, an EV connector and an HMI circuit, the HMI circuit including a proximity input terminal configured to receive a proximity signal from an EV connector indicating a state of a handle button of the EV connector, a ground terminal, a current source input coupled between the proximity input terminal and the ground terminal, a comparator connected between the proximity input terminal and the ground terminal to provide an output representing a state of the handle button when the current source is activated by the control input and an output terminal to which the output of the comparator is connected, the output terminal being connected to the EVSE control electronics, wherein the state of the handle button is utilized as an input to the HMI circuit.