Power Control Circuit for Inrush Limiting and Residual Voltage Discharge
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Solution Overview
Problem
Existing power control devices for electronic devices face challenges in managing inrush currents during power-on and residual voltage discharge during power-off, leading to potential device damage and abnormal operations due to high production costs and complexity.
Innovation Solution
A power control device comprising a high-pass filtering unit for minimizing inrush currents and a transistor-based active discharging mechanism to rapidly discharge residual voltages, utilizing a high-pass filtering unit and transistors with current limiting units to control signal connections and currents based on voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated protection IC and many passive components are used to restrain inrush current, then inrush current damage is prevented, but production cost and area cost increase significantly
Solution Approach 1:
The patent combines the inrush current protection function with the existing power supply circuit by using the switch transistor that is already part of the power supply system. The protection function is integrated into the power supply control logic rather than being a separate dedicated protection circuit, thereby reducing component count and area cost while maintaining protection effectiveness.
Solution Approach 2:
The switch transistor in the power supply circuit is made to serve dual purposes: normal power supply switching and inrush current protection. By controlling the switch transistor's turn-on timing and duration, the circuit achieves both power supply control and inrush current limitation without requiring additional dedicated protection components.
2Stability of the object's composition
If a regulated capacitor with large capacitance is located at the power supply terminal for power stability, then power stability is improved, but residual voltage remains after power off causing abnormal operation
Solution Approach 1:
The patent implements a preliminary discharging action by controlling the switch transistor to remain on for a predetermined time period after the power supply is turned off. This ensures that the regulated capacitor has sufficient time to discharge its residual voltage before the system considers the power-off complete, preventing abnormal operations during subsequent power-on attempts.
Solution Approach 2:
The power supply control unit monitors the power supply state and automatically adjusts the switch transistor's operation based on whether the system is in power-on or power-off mode. This feedback mechanism ensures the capacitor is discharged appropriately during power-off while maintaining stable power delivery during normal operation.
3Speed
If the electronic device is powered on again before residual voltage discharging is finished, then power on speed is improved, but abnormal operation occurs and the device cannot be turned on
Solution Approach 1:
The system performs a preliminary discharging operation during the power-off state by keeping the switch transistor on for a predetermined time period. This preliminary action ensures residual voltage is removed before the next power-on attempt, guaranteeing reliable operation while allowing quick power-on once the discharging period is complete.
Solution Approach 2:
The patent implements a periodic control pattern where the switch transistor is turned on during power-off for a predetermined time period to discharge the capacitor, then turned off to allow normal power-on operation. This periodic switching ensures proper voltage management while maintaining acceptable power-on timing.
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 solution effectively reduces inrush currents and rapidly discharges residual voltages, preventing device damage and ensuring normal operation by generating stable output signals and controlling transistor states for safe power management.
Implementation Method 1
a high-pass filtering unit for performing a filtering process on an input signal for generating an output signal
Implementation Method 2
The first transistor includes a first terminal coupled to a first voltage generator, a second terminal and a third terminal coupled to a ground terminal for controlling a signal connection between the first terminal of the first transistor and the third terminal of the first transistor according to the voltage level of the second terminal of the first transistor
Implementation Method 3
The first current limiting unit is coupled between the first voltage generator and the second terminal of the first transistor for controlling a conducting current from the first terminal of the first transistor to the third terminal of the first transistor
Implementation Method 4
The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal and a third terminal coupled to a ground terminal for controlling a signal connection between the first terminal of the second transistor and the third terminal of the second transistor according to the voltage level of the second terminal of the second transistor
Data Source
AI summary
A power control device for an electronic device for enhancing power stability when the electronic device is powered on including a high-pass filtering unit for performing a filtering process on an input signal for generating an output signal, and a control unit coupled to the high-pass filtering unit and a first voltage generator of the electronic device for outputting the output signal to the first voltage generator according to the voltage level of the output signal.