MEMS Switch Arc Suppression via Parallel Over-Current Protection
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Solution Overview
Problem
Conventional circuit breakers are large, slow, complex, and expensive, and they often form arcs during switching events, which can damage contacts and pose safety hazards due to the formation of arcs between contacts during physical separation.
Innovation Solution
A micro-electromechanical system (MEMS) based switching system with integrated over-current protection circuitry that forms a conductive path in parallel with the MEMS switching circuitry to suppress voltage and current levels during switching events, using a balanced diode bridge and pulse circuit to rapidly switch the MEMS switch and prevent arc formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electromechanical switches are used in circuit breakers, then the switching mechanism can physically separate contacts to interrupt current, but the contacts form arcs during separation which damage the contacts and pose safety hazards
Solution Approach 1:
A current transfer switch (CTS) is introduced as an intermediary device between the power source and the load. The CTS transfers current away from the MEMS switch during switching events, preventing arc formation at the MEMS contacts. This mediator allows the MEMS switch to open without bearing the full current load, eliminating the harmful arc effect.
Solution Approach 2:
The system performs preliminary action by detecting when a MEMS switch is about to open and preemptively transferring the current through the CTS before the MEMS contacts separate. This advance current transfer prevents the formation of arcs that would otherwise occur during contact separation, protecting the contacts from damage.
2Speed
If MEMS switches are used for fast switching, then switching speed is improved, but voltage spikes and current surges occur during switching events that can damage the switch
Solution Approach 1:
Snubber circuits are implemented as protective elements that cushion against voltage spikes and current surges during MEMS switching events. These circuits are pre-configured to absorb and dissipate the harmful transient energy that occurs when the MEMS switch rapidly changes state, protecting the switch from damage while maintaining fast switching performance.
Solution Approach 2:
The current transfer switch acts as a mediator that handles the high current and voltage transients during switching events, shielding the MEMS switch from these harmful effects. By transferring the current burden to the CTS during critical moments, the MEMS switch can operate at high speeds without exposure to damaging voltage spikes and current surges.
3Speed
If solid-state switches are used instead of electromechanical switches, then switching speed is improved and no physical contact separation occurs, but leakage current and voltage drop generate excess heat
Solution Approach 1:
The invention replaces traditional electromechanical switches with MEMS switches that utilize micro-electromechanical principles rather than bulky mechanical components. This substitution achieves fast switching speeds while minimizing contact area and improving thermal management compared to conventional electromechanical systems.
Solution Approach 2:
The system dynamically changes operating parameters by switching between different configurations of the MEMS switch and CTS. During normal operation, the MEMS switch carries full current for efficient conduction. During switching events, parameters change as the CTS takes over current carrying duty, allowing the MEMS switch to operate in a regime that minimizes heat generation while maintaining fast response.
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 MEMS based switching system effectively suppresses arc formation during switching events, reducing contact damage and safety hazards while enabling fast and efficient switching with reduced energy loss and heat generation.
Implementation Method 1
A first over-current protection circuitry connected in a parallel circuit with the micro-electromechanical system switching circuitry. The first over-current protection circuitry is configured to momentarily form an electrically conductive path in response to a first switching event
Implementation Method 2
using a balanced diode bridge and pulse circuit to rapidly switch the MEMS switch and prevent arc formation
Implementation Method 3
The second over-current protection circuitry is configured to momentarily form an electrically conductive path in response to a second switching event. The electrically conductive path forms a parallel circuit with the micro-electromechanical system switching circuitry for suppressing a current flow through the contacts
Data Source
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AI summary
A system that includes micro-electromechanical system switching circuitry (206) is provided. The system may include a first over-current protection circuitry (2061) connected in a parallel circuit with the micro-electromechanical system switching circuitry (206) for suppressing a voltage level across contacts of the micro-electromechanical system switching circuitry (206) during a first switching event, such as a turn-on event. The system may further include a second over-current protection circuitry (2062) connected in a parallel circuit with the micro-electromechanical system switching circuitry (206) for suppressing a current (0) flow through the contacts of the micro-electromechanical system switching circuitry (206) during a second switching event, such as a turn-off event.