High-Voltage Interlock Diagnosis Using Parallel Resistor Branches
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Solution Overview
Problem
Conventional interlock circuits for high voltage connectors in eco-friendly vehicles fail to accurately diagnose the engagement state due to the influence of resistor short circuits, leading to incorrect identification of connector disengagement.
Innovation Solution
An interlock diagnosing system with parallel-connected resistors of varying resistance values, allowing for accurate detection of engaged and disengaged connectors through resistance value calculation, and a detector to identify specific disengaged connectors and record diagnostic trouble codes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If resistors are connected in series in the interlock circuit, then the circuit structure is simple, but when a resistor is burned out and short-circuited, the connector engagement state cannot be accurately detected
Solution Approach 1:
The patent divides the interlock circuit into multiple independent parallel branches, each containing a resistor and connector combination. This segmentation allows the system to detect the engagement state of each connector individually through voltage division, preventing a single resistor failure from affecting the detection of other connectors. The detector can identify which specific connector is disengaged by measuring the voltage at each branch point.
Solution Approach 2:
The patent changes the circuit configuration from series to parallel connection, fundamentally altering the electrical parameters (voltage distribution, current paths) of the interlock circuit. In the parallel configuration, each branch maintains its own voltage potential, allowing the detector to distinguish between different connector states by measuring voltage differences. This parameter change ensures that resistor failures do not cause complete circuit failure or inaccurate readings.
2Reliability
If conventional interlock circuits are used, then the system can detect connector disconnection, but resistor short circuits cause false positive readings indicating normal connection
Solution Approach 1:
The patent implements a feedback mechanism where the detector continuously monitors the voltage distribution across the parallel resistor branches and compares the measured values against expected values for engaged and disengaged states. When a resistor fails or a connector disengages, the voltage distribution changes, and the detector provides feedback to identify the specific fault condition. This feedback loop enables the system to distinguish between normal operation, connector disengagement, and resistor failures.
Solution Approach 2:
The patent introduces the parallel resistor network as an intermediary element between the power supply and the detector. This intermediary structure allows the system to translate physical connector engagement states into distinct voltage signals that the detector can interpret. The resistors act as mediators that create measurable voltage differences based on connector position, enabling accurate detection while isolating the impact of individual resistor failures.
3Measurement precision
If resistors are connected in parallel with varying resistance values, then accurate detection of engaged and disengaged connectors is enabled, but the device complexity increases
Solution Approach 1:
The patent employs asymmetric resistance values in the parallel branches to create unique voltage signatures for each connector position. By using different resistance values (R1, R2, R3, etc.) instead of identical values, each branch produces a distinct voltage division ratio when engaged. This asymmetry allows the detector to identify the specific engagement state of each connector by comparing the measured voltage against predetermined thresholds or patterns, enabling precise detection without requiring complex additional hardware.
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 system enables precise identification of engaged and disengaged connectors, minimizing the impact of resistor failures and ensuring rapid voltage reduction to safe levels upon disconnection, enhancing safety and maintenance efficiency.
Implementation Method 1
a detection circuit (10) extending between a transmitter (30) providing voltage and a receiver (40) receiving the voltage provided by the transmitter (30)
Implementation Method 2
a plurality of resistors (20), each being connected in parallel to the detection circuit (10) via a respective one of a plurality of connectors (C1, C2, C3, and C4) engaged between the plurality of resistors (20) and the detection circuit (10)
Data Source
AI summary
An interlock diagnosing system and method for a high voltage device includes: a detection circuit between a transmitter providing a voltage and a receiver receiving the voltage provided by the transmitter; a plurality of resistors connected in parallel to the detection circuit via a respective plurality of connectors engaged between the plurality of resistors and the detection circuit; and a detector detecting engaged states of the plurality of connectors based on at least one of the voltage provided by the transmitter or the voltage received by the receiver, or both. The detector calculates a resistance value of the detection circuit based on the voltage provided by the transmitter and the voltage received by the receiver and detects the engaged states of the plurality of connectors based on the calculated resistance value. Each resistor has a different resistance value from each other. The detector detects a disengaged connector among the plurality of connectors based on the calculated resistance value.