Parallel Battery Reverse Polarity Protection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power supply systems with multiple batteries connected in parallel face issues with reverse polarity protection, leading to potential damage, voltage drops, and reduced battery life due to the use of blocking diodes, which are not effectively addressed by conventional methods.
Innovation Solution
A power supply circuit with parallel-connected power sources, featuring reverse polarity protection circuits and bypass control mechanisms using transistors and Schottky diodes to manage current flow and voltage, allowing for independent control of bypass channels based on terminal voltage conditions to prevent reverse current blocking and enhance supply voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blocking diodes are used to prevent reverse current flow in parallel battery systems, then reverse polarity protection is improved, but voltage drops increase and battery service life decreases
Solution Approach 1:
The patent changes the electrical parameters of the protection mechanism by using MOSFETs with dynamically controllable resistance instead of fixed diode voltage drops. The control circuit adjusts the MOSFET resistance based on battery state (charged/discharged) to minimize voltage drops while maintaining protection functionality, directly addressing the contradiction between protection reliability and battery service life.
Solution Approach 2:
The invention introduces dynamic control of the protection circuit through a control circuit that monitors battery voltage and current direction. The MOSFETs are dynamically switched between high-impedance (protection mode) and low-impedance (normal operation mode) states, making the protection mechanism adaptive rather than static, thereby reducing unnecessary voltage drops during normal operation.
2Reliability
If blocking diodes are used to prevent reverse current flow, then reverse polarity protection is improved, but resultant supply voltage decreases
Solution Approach 1:
The patent changes the electrical parameters by replacing the fixed forward voltage drop of diodes (typically 0.7V for silicon) with controllable MOSFET on-resistance that can be minimized through proper gating. This parameter change allows the supply voltage to be maintained closer to the battery voltage while preserving reverse polarity protection capabilities.
Solution Approach 2:
The control circuit acts as an intermediary that manages the transition between protection and normal operation modes. It monitors system state and controls the MOSFET gate voltages accordingly, enabling the protection circuit to function as an intelligent mediator rather than a passive voltage-dropping element, thus preserving supply voltage while maintaining protection.
3Reliability
If conventional reverse battery protection circuits are used, then reverse polarity protection is provided, but device complexity increases due to additional components
Solution Approach 1:
The patent implements multi-functionality by using the same MOSFET-based protection circuit for both reverse polarity protection and current direction control in parallel battery configurations. The control circuit serves multiple purposes: monitoring voltage, determining current direction, and controlling MOSFET states, thereby reducing the need for separate dedicated components for each function and simplifying the overall device complexity.
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 solution effectively prevents damage from reverse polarity, reduces voltage drops, and extends battery life by selectively bypassing diode blocking, ensuring reliable power supply and improved system performance.
Implementation Method 1
a Schottky diode connected in parallel to the first transistor to provide reverse current blocking and reverse polarity protection
Implementation Method 2
a first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a first body diode of the first transistor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A power supply circuit 100 is provided that includes first and second power sources 108; 110 coupled in parallel, a first circuit path that provides reverse current blocking and reverse polarity protection associated with positive terminals 124; 128 of the respective first and second power sources, a second circuit path that bypasses current blocking of the first circuit path, a third circuit path that provides reverse polarity protection associated with negative terminals 126; 130 of the respective first and second power sources, and a bypass control circuit 106 that controls the second circuit path based on determination of a predetermined condition.