USB Wakeup Circuit Using Capacitor-Powered Vibration Sensing
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Solution Overview
Problem
Current USB devices require maintenance of a reduced power state to generate a wake-up signal, preventing them from being completely powered off and lacking security in power management access.
Innovation Solution
A circuit with a capacitor is attached to the USB interface, charging during normal operation and providing power to a vibration sensor when in a reduced power state, allowing the sensor to generate a wake-up signal by connecting to the USB interface when a vibration is detected, enabling the system to wake up without external power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If USB devices maintain a reduced power state to generate wake-up signals, then wake-up functionality is enabled, but the devices cannot be completely powered off and security in power management access is lacking
Solution Approach 1:
The capacitor is charged in advance during normal operation before the system enters reduced power state. This preliminary energy storage enables the vibration sensor to operate independently without external power, resolving the contradiction between complete power-off capability and wake-up functionality.
Solution Approach 2:
The capacitor acts as an intermediary energy source between the powered and unpowered states. It bridges the gap by providing temporary power to the vibration sensor when the system is completely off, enabling wake-up functionality without requiring continuous power maintenance.
2Use of energy by moving object
If USB devices are completely powered off, then power consumption is minimized, but wake-up functionality cannot be achieved
Solution Approach 1:
Energy is stored in the capacitor before the system enters the completely powered-off state. This advance preparation allows the vibration sensor to be activated by vibration events even when no external power is supplied, achieving both complete power-off and wake-up functionality.
Solution Approach 2:
The vibration sensor serves itself by detecting mechanical vibrations and triggering the wake-up sequence without requiring external power or control signals. The capacitor provides the necessary power autonomously, enabling the device to wake up on its own in response to physical stimuli.
3Device complexity
If standard USB power management is used, then simplicity is maintained, but security provision for controlling power management access is absent
Solution Approach 1:
The vibration sensor acts as an intermediary trigger mechanism that bypasses the need for software-based power management protocols. By using physical vibration detection instead of electrical signaling, the system adds a layer of security that cannot be accessed or manipulated through standard USB interfaces.
Solution Approach 2:
The patent replaces the electrical/software-based power management system with a mechanical vibration detection system. This substitution eliminates security vulnerabilities in the electrical interface while maintaining wake-up functionality, as mechanical vibrations cannot be faked through software or electrical manipulation.
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
Enables complete power-off of USB devices without external power, providing secure and efficient wake-up functionality through a physically small and invisible circuit that can be integrated into existing USB devices.
Implementation Method 1
A capacitor in the circuit is charged by receiving power from a power pin of the universal serial bus interface while the data processing system is not in a reduced power state
Implementation Method 2
When a vibration is detected by the vibration sensor, a switch connects the vibration sensor to the data pin of the universal serial bus interface
Data Source
AI summary
A circuit is attached in parallel to a universal serial bus interface of a data processing system. A capacitor in the circuit is charged by receiving power from a power pin of the universal serial bus interface while the data processing system is not in a reduced power state. A vibration sensor is unpowered while the data processing system is not in a reduced power state. The vibration sensor is disconnected from a data pin of the universal serial bus interface while the data processing system is not in a reduced power state. When the data processing system enters a reduced power state, the capacitor provides power to the vibration sensor. When a vibration is detected by the vibration sensor, a switch connects the vibration sensor to the data pin of the universal serial bus interface, providing a wake up signal to the data processing system.