Battery Pack Insulation Measurement Circuit With Single-Switch Output
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Solution Overview
Problem
Existing insulation resistance measuring devices for battery packs require multiple switches and a voltage source, leading to a complex circuit and the need for multiple input terminals in an analog-digital converter, complicating the configuration and driving method.
Innovation Solution
A simplified insulation resistance measuring device with series-connected resistors and a single switch, eliminating the need for a voltage source and reducing the number of output terminals by outputting a single signal to the analog-digital converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a typical insulation resistance measuring device uses two switches and a voltage source for measuring positive and negative insulation resistors, then the measurement function is complete, but the circuit complexity and device complexity increase
Solution Approach 1:
The patent merges the measurement of positive and negative insulation resistors into a single integrated circuit configuration. By connecting the first and second resistors in series between the positive electrode and ground, and the third and fourth resistors in series between the negative electrode and ground, with a single switch controlling both measurement paths, the device reduces component count while maintaining complete measurement functionality. This merging approach directly reduces device complexity without sacrificing measurement capability.
Solution Approach 2:
The single switch in the patent serves multiple functions: it controls the measurement path for both positive and negative insulation resistors, replacing the need for separate switches. The resistor network is designed to handle both measurement tasks universally, allowing one switch to manage two measurement functions, thereby simplifying the overall circuit architecture.
2Reliability
If two switches are used for switching operations in the insulation resistance measuring device, then both positive and negative insulation resistors can be measured, but the driving method becomes complicated
Solution Approach 1:
The patent combines the control logic for measuring both positive and negative insulation resistors into a single switch operation. The series-connected resistor networks are designed so that one switch can sequentially or simultaneously control the measurement paths for both insulation resistors, eliminating the need for coordinated two-switch operations and simplifying the driving method.
3Measurement precision
If first and second output signals are input to an analog-digital converter through two voltage division resistors, then both insulation resistor measurements are captured, but the number of input terminals required increases
Solution Approach 1:
The patent merges the output signals from the positive and negative insulation resistor measurements into a single output path. By designing the resistor networks to produce a combined output signal that contains information about both insulation resistors, the device reduces the number of ADC input terminals from two to one, simplifying the interface while maintaining measurement precision for both channels.
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 simplified configuration reduces the number of switches and input terminals, simplifying the circuit and driving method, and minimizing the complexity of peripheral devices.
Implementation Method 1
first and second resistors for voltage division, which are connected in parallel with the positive insulation resistor disposed between the positive electrode and the ground, and third and fourth resistors for voltage division, which are connected in parallel with the negative insulation resistor disposed between the negative electrode and the ground
Data Source
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AI summary
Provided is an insulation resistance measuring device for measuring a positive insulation resistor disposed between a positive electrode of a battery pack and a ground and a negative insulation resistor disposed between the ground and a negative electrode of the battery pack, the insulation resistance measuring device including: first and second resistors connected in series between the positive electrode of the battery pack and the ground; third and fourth resistors connected in series between the ground and the negative electrode of the battery pack; an output terminal connected between the third and fourth resistors; and a switch connected between a contact between the first and second resistors and the negative electrode of the battery pack.