Power Supply Circuit Topology for Reverse Connection Breakdown Prevention
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Solution Overview
Problem
Existing power supply circuits fail to prevent internal breakdown when a power supply and ground are connected in reverse, leading to potential damage and inrush currents.
Innovation Solution
A power supply circuit design incorporating NMOS transistors, Zener diodes, and a gate controller with a charge pump circuit to manage and control transistor states, preventing inrush currents by ensuring proper voltage levels and transistor operation even when power supply and ground are reversed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple switch circuit is connected to a power supply line to prevent breakdown, then the device complexity is reduced, but the reliability is insufficient when power supply and ground are connected in reverse
Solution Approach 1:
The power supply circuit is divided into multiple functional segments: a first switch circuit for normal operation, a second switch circuit for reverse connection detection, and a control circuit. Each segment performs a specific function, allowing the system to reliably prevent breakdown while maintaining manageable complexity through modular design.
Solution Approach 2:
The control circuit proactively monitors the power supply connection status and activates the second switch circuit before reverse connection can cause damage. By detecting potential reverse connection conditions in advance and preemptively controlling the switch states, the circuit prevents breakdown rather than reacting after damage occurs.
2Reliability
If additional circuits are added to detect reverse connections and control transistor states, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The control circuit serves multiple functions simultaneously: it monitors power supply connection status, detects reverse connections, controls both the first and second switch circuits, and manages transistor states. By consolidating these functions into a single multi-functional control unit, the circuit achieves comprehensive reverse connection protection without proportionally increasing overall system complexity.
Solution Approach 2:
The second switch circuit acts as an intermediary between the power supply line and the internal circuit. It is controlled by the control circuit to insert or remove itself from the circuit path based on detected connection status, providing a controlled interface that protects the internal circuit from reverse connection damage while maintaining normal operation when connections are correct.
3Adaptability or versatility
If the switch circuit is designed to handle high input voltages, then the adaptability is improved, but the loss of energy increases due to inrush currents
Solution Approach 1:
The control circuit activates the second switch circuit in advance to establish proper voltage levels and transistor states before the full power supply voltage is applied to the internal circuit. This preliminary action prevents sudden inrush currents by gradually establishing safe operating conditions, allowing the circuit to handle high input voltages adaptively while minimizing energy loss.
Solution Approach 2:
The control circuit continuously monitors the power supply connection status and voltage levels, using this feedback information to dynamically adjust the switch circuit states. When reverse connection or abnormal voltage conditions are detected, the feedback mechanism triggers appropriate switch configurations to protect the circuit, enabling adaptable handling of various voltage conditions while preventing harmful inrush currents through real-time control adjustments.
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
Effectively prevents internal breakdown and inrush currents by maintaining stable transistor operation and voltage levels, accommodating high input voltages and reverse connections.
Implementation Method 1
a Zener diode including an anode connected to the input terminal, and a cathode connected to the second node
Data Source
AI summary
A power supply circuit of an embodiment includes a first transistor including a source connected to an input terminal, and a gate connected to a first node; a second transistor including a drain connected to a drain of the first transistor, and a source connected to an output terminal; a third transistor including a source connected to the input terminal, a drain connected to the first node, and a gate connected to a second node; and a Zener diode including an anode connected to the input terminal, and a cathode connected to the second node.