Multi-Input Power Circuit Using One NTC for Inrush Suppression
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Solution Overview
Problem
Existing multi-input power systems require multiple negative temperature resistors for inrush current suppression, leading to complex and costly designs.
Innovation Solution
A multi-input power system with a simplified design using a single NTC thermistor and diodes to suppress inrush current, incorporating filter-rectification, boost power factor correction, and DC-to-DC conversion circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple negative temperature resistors are used for inrush current suppression in multi-input power systems, then inrush current can be suppressed for each input, but the device complexity and component count increase
Solution Approach 1:
The patent merges multiple inrush current suppression functions into a single NTC thermistor by configuring it in the feedback circuit of the power factor correction module. This single component suppresses inrush current from multiple input power sources simultaneously, eliminating the need for separate NTC thermistors for each input and thereby reducing device complexity while maintaining reliability
Solution Approach 2:
The single NTC thermistor in the feedback circuit serves multiple functions: it suppresses inrush current from multiple input power sources, provides over-current protection, and regulates output voltage. This multi-functional design reduces the total component count while achieving comprehensive protection across all input channels
2Reliability
If multiple negative temperature resistors are used for inrush current suppression, then each input power source can be protected, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple protection functions into a single NTC thermistor component in the feedback circuit, reducing the bill of materials from multiple NTC thermistors to one, thereby directly lowering component costs and simplifying the manufacturing process while maintaining comprehensive inrush current protection for all input power sources
3Reliability
If multiple negative temperature resistors are used for inrush current suppression, then each input channel can be protected independently, but the system volume increases
Solution Approach 1:
The patent consolidates multiple inrush current suppression functions into a single NTC thermistor located in the feedback circuit, eliminating the need for separate NTC thermistors for each input channel. This merging approach significantly reduces the total volume occupied by suppression components while maintaining the ability to protect all input power sources simultaneously
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 system effectively suppresses inrush current while minimizing component count, cost, and volume, applicable to multi-input AC and DC power structures.
Implementation Method 1
a resistor R31, which is an NTC thermistor
Data Source
AI summary
A multi-input power system with an inrush current suppression function receives at least two input power sources, and includes at least two filter-rectification circuits, at least two boost PFC circuits, a current suppression circuit, and a DC-to-DC conversion circuit. Each filter-rectification circuit correspondingly receives the input power source, and converts the at least two input power sources into at least two rectified voltages. Each boost PFC circuit is correspondingly connected to the filter-rectification circuit, receives the rectified voltage, and performs a power factor correction to the rectified voltage to provide a conversion voltage. The current suppression circuit is connected to the at least two filter-rectification circuits and the at least two boost PFC circuits. The DC-to-DC is connected to the at least two boost PFC circuits and the current suppression circuit, receives the conversion voltage and converts the conversion voltage into an output voltage.