DC-DC Converter with Reverse Parallel Diode for Battery Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC-DC converters face challenges in efficiently charging secondary batteries outdoors without AC power, as they struggle to control output voltage and current when the primary battery's voltage decreases, and are difficult to downsize and produce at lower cost due to complex component requirements.
Innovation Solution
A DC-DC converter comprising a step-up switching regulator with an inductance element, rectifier element, switching element, and controlling circuit that allows output voltage control from lower to higher than the input voltage without switching step-up and step-down operations, incorporating a current detection circuit to restrict output current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a normal step-up DC-DC converter with a diode is used, then the circuit structure is simple, but the output voltage is clamped and cannot be controlled below the input voltage, making current restriction impossible
Solution Approach 1:
The patent inverts the conventional diode connection by placing it in reverse parallel between the input and output terminals. This inversion allows the diode to conduct when output voltage exceeds input voltage plus diode forward voltage, enabling current restriction functionality while maintaining simple circuit structure.
Solution Approach 2:
The patent makes the step-up DC-DC converter universally applicable to both step-up and step-down charging scenarios. By adding the reverse parallel diode and controlling the switching element, the converter can restrict output current in both voltage conditions (output lower than and higher than input voltage), eliminating the need for separate step-up and step-down circuits.
2Productivity
If a step-up DC-DC converter is used to charge secondary battery when primary battery voltage is low, then charging capability is improved, but output current cannot be restricted when secondary battery voltage is lower than primary battery voltage
Solution Approach 1:
The reverse parallel diode configuration enables current restriction in the step-up mode by allowing the diode to conduct when output voltage exceeds input voltage plus diode forward voltage, thereby restricting current flow and enabling safe charging operation.
Solution Approach 2:
The patent implements feedback control through the controlling circuit that monitors output conditions and adjusts the switching element accordingly. This feedback mechanism enables automatic current restriction and prevents overcharging, improving ease of operation and safety.
3Adaptability or versatility
If dual-stage step-up and step-down regulators are used, then output voltage control flexibility is improved, but the number of components increases making downsizing difficult
Solution Approach 1:
The patent merges the step-up and step-down functions into a single step-up DC-DC converter circuit by strategically placing a reverse parallel diode. This consolidation maintains output voltage control flexibility for both charging modes while significantly reducing the number of components compared to dual-stage regulators.
Solution Approach 2:
The single converter circuit is designed to perform multiple functions: step-up conversion for low-voltage charging and step-down conversion for high-voltage charging. The reverse parallel diode enables the circuit to adapt to different voltage conditions, providing universal charging capability without requiring separate circuits.
4Measurement precision
If multiple regulators and control circuits are used, then charging control precision is improved, but manufacturing cost and device size increase
Solution Approach 1:
The patent combines multiple control functions (step-up control, step-down control, current restriction) into a single controlling circuit that manages one switching element and one reverse parallel diode. This integration maintains charging control precision while reducing manufacturing complexity and cost.
Solution Approach 2:
The single controlling circuit is designed to handle multiple charging scenarios and control requirements universally. It can switch between step-up and step-down modes, restrict current in both directions, and protect against overcharging, eliminating the need for multiple specialized control circuits.
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 efficient, cost-effective, and compact charging of secondary batteries by controlling output voltage and current, reducing component complexity and electric loss, while allowing charging without AC power sources.
Implementation Method 1
an inductance element and a rectifier element connected in series between a voltage input terminal to accept input direct current voltage and a first output terminal; a switching element connected between a connection node of the inductance element and the rectifier element and a reference potential point
Data Source
AI summary
A DC-DC converter includes: an inductance element and a rectifier element connected in series between a voltage input terminal to accept input direct current voltage and a first output terminal; a switching element connected between a connection node of the inductance element and the rectifier element and a reference potential point; and a controlling circuit to form a signal to control on/off of the switching element. The controlling circuit controls on/off of the switching element to control current through the inductance element, and a voltage applied to the voltage input terminal to accept the input direct current voltage is output via a second output terminal as a reference potential of a circuit at a latter stage, so that an output voltage is controllable from a lower to higher voltage than the input direct current voltage without switching step-up and step-down operations.