USB Connection Control for Empty Battery Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for connecting portable devices to USB hosts can fail when the device's battery is empty, as they require sufficient stored energy to power up software components for charging and data transfer, which may not be available, preventing charging and data transfer compliance with USB specifications.
Innovation Solution
An apparatus with a detection circuit and charging circuit that generates a start-up request signal upon USB attachment, determining if the battery power meets a predetermined criterion to decide between charging mode and USB connection mode, ensuring sufficient energy is stored before initiating the USB connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the portable device attempts to connect to USB host immediately upon attachment, then the connection procedure can be initiated promptly, but the device may fail to power up software components due to insufficient battery energy
Solution Approach 1:
The charging circuit is activated before the USB connection procedure to preliminarily charge the battery and ensure sufficient energy is available for software components during connection. This preliminary charging action prevents connection failure due to insufficient power.
Solution Approach 2:
The system performs a preliminary power assessment to determine whether the battery has sufficient energy before initiating the USB connection procedure. This preliminary check ensures that connection attempts only occur when power requirements can be met.
2Reliability
If the device delays USB connection to charge the battery first, then sufficient energy can be stored for reliable operation, but the time to establish data transfer connection increases
Solution Approach 1:
The charging circuit provides excessive current temporarily during the connection procedure to ensure sufficient energy is available, rather than using the standard limited current. This partial excessive charging action ensures reliable operation without requiring prolonged delay.
Solution Approach 2:
The system performs a preliminary power assessment to determine whether the battery has sufficient energy before initiating the USB connection procedure. This preliminary check avoids unnecessary delays by only charging when required.
3Adaptability or versatility
If the portable device uses standard USB current limits during connection procedure, then compliance with USB specification is maintained, but insufficient energy is available to power up software components for charging and data transfer
Solution Approach 1:
The charging circuit provides excessive current temporarily during the connection procedure to ensure sufficient energy is available for software components, exceeding the standard USB current limits. This partial excessive action is confined to the connection procedure only.
Solution Approach 2:
The current provision is segmented into two phases: during the connection procedure, excessive current is provided to power up software components; after connection is established, standard USB current limits are applied for normal operation. This segmentation allows compliance with USB specification while ensuring sufficient energy during the critical connection phase.
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 USB connection even with an empty or weak battery by delaying the connection until sufficient energy is stored, allowing compliant charging and data transfer, and facilitating software-controlled charging and data transfer.
Implementation Method 1
a detection circuit, operable to detect attachment of a USB device
Implementation Method 2
a charging circuit, for charging a battery of a portable device using current drawn from a USB device
Data Source
Figure 1~2
Figure 3
Figure 4A
AI summary
An apparatus comprises: a connector, for providing a physical connection to a USB device, a detection circuit, operable to detect attachment of a USB device; and a charging circuit, for charging a battery of a portable device using current drawn from a USB device, the charging circuit being operable, if it is detected that a USB device is attached, to generate a start-up request signal. The apparatus has a charging mode in which power is provided by the charging circuit to the battery, and a USB connection mode for providing a USB connection. The apparatus also comprises a control unit, operable in response to the start-up request signal to determine whether power supplied by the battery meets a predetermined criterion. The control unit is also operable, if it is determined that the predetermined criterion is not met, to control the apparatus to be in the charging mode and prevent the apparatus from entering the USB connection mode and operable, if it is determined that predetermined criterion is met, to control the apparatus to enter the USB connection mode.