Input Port Charging Control for Electrical Backfeed Protection
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Solution Overview
Problem
During charging scenarios of power supplies, the disconnection of an external power source can lead to backfeed, where electrical power is fed back into the input, posing safety risks such as injury from exposed electrical connections.
Innovation Solution
An electrical system with an input port circuit, rechargeable energy storage element, and control circuit that monitors current and voltage levels to apply a charging control waveform, stopping the charging process when threshold values are satisfied to prevent backfeed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power supply continues charging after external power disconnection, then the energy storage element remains charged, but backfeed occurs creating safety hazards
Solution Approach 1:
The control circuit continuously monitors the input port voltage and charging current to detect disconnection events. When the external power source is disconnected, the control circuit detects the absence of input voltage and immediately stops the charging waveform generation, preventing backfeed to the input port
Solution Approach 2:
The control circuit proactively stops the charging process upon detecting disconnection before backfeed can occur. By monitoring input voltage levels and charging current in real-time, the system takes preliminary protective action to prevent the harmful condition rather than responding after backfeed begins
2Reliability
If the control circuit continuously monitors charging parameters, then backfeed can be prevented, but system complexity increases
Solution Approach 1:
The control circuit performs multiple functions: generating the charging control waveform, monitoring input voltage, detecting disconnection events, and preventing backfeed. By integrating these functions into a single control unit rather than separate dedicated circuits, the system achieves reliable backfeed protection without proportionally increasing complexity
Solution Approach 2:
The control circuit uses its existing monitoring capabilities for charging management to simultaneously detect disconnection events and prevent backfeed. The same sensors and control logic used for normal charging operation are leveraged for safety protection, avoiding the need for additional dedicated backfeed protection hardware
Data Source
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AI summary
Electrical systems may include an input port circuit configured to receive electrical energy from an external power source, a rechargeable energy storage element operable to store electrical energy received via the input port circuit; and at least one control circuit that is operable to apply a charging control waveform at the input port circuit causing the rechargeable energy storage element to be charged in a controlled manner with regard to a current applied to the rechargeable energy storage element, provide a level signal indicative of flow of current and/or power between the input port circuit and the rechargeable energy storage element, monitor the level signal with regard to a threshold value, and, stop applying the charging control waveform at the input port circuit upon a determination that the level signal satisfies the threshold value. Methods and computer program products are also disclosed.