Fuel Injection Power Supply Using MOSFET Rectifier Phase Control
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Solution Overview
Problem
Existing power supply apparatuses for fuel injection systems in internal combustion engines require expensive comparators to distinguish voltage phases, increasing costs and complexity, while also facing challenges in maintaining efficient voltage output across varying engine speeds.
Innovation Solution
A power supply apparatus using a diode bridge full-wave rectifier circuit with MOSFETs and a control voltage supply circuit that eliminates the need for phase distinction by using a control voltage supply control switch to manage MOSFET ON/OFF based on drain-source voltage polarity, reducing channel loss and eliminating the need for comparators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If comparators are used to distinguish voltage phases, then phase detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the phase detection function from complex comparator circuits and implements it using the inherent properties of the diode bridge rectifier circuit. The control unit detects voltage phase information directly from the rectified output without requiring separate phase detection comparators, thereby eliminating unnecessary circuit components while maintaining detection accuracy.
Solution Approach 2:
The diode bridge rectifier circuit is made multi-functional by enabling it to perform both voltage rectification and phase detection simultaneously. The control unit utilizes the rectified voltage signal for dual purposes: power generation control and phase identification, eliminating the need for dedicated phase detection circuits and reducing overall system complexity.
2Productivity
If MOSFETs are controlled with precise phase information, then power generation efficiency is improved, but device complexity increases
Solution Approach 1:
The system achieves self-service by using the rectified voltage signal from the diode bridge to automatically provide phase information for MOSFET control. The control unit extracts phase data from the existing voltage waveform without requiring external phase detection circuits, enabling the system to self-regulate power generation efficiency while minimizing additional control circuitry.
Solution Approach 2:
The control unit dynamically adjusts MOSFET switching parameters based on the detected voltage phase and engine speed conditions. By changing the switching frequency and duty cycle parameters according to real-time voltage characteristics, the system optimizes power generation efficiency across varying operating conditions without increasing structural complexity.
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
This solution reduces costs by eliminating the need for expensive comparators and simplifies connections by eliminating phase distinction, while maintaining efficient voltage output across varying engine speeds through effective MOSFET control.
Implementation Method 1
a magneto AC generator driven by the internal combustion engine
Implementation Method 2
a diode bridge full-wave rectifier circuit which rectifies an AC voltage given to the n input terminals
Data Source
AI summary
A power supply apparatus comprised of a bridge circuit made up of rectification diodes and MOSFETs for rectifying an output of a generator through a full-wave rectifier circuit comprised of rectification diodes and parasitic diodes of the MOSFETs and obtaining a supply voltage of a fuel injection apparatus, the power supply apparatus being comprised of an FET control section which turns ON/OFF the MOSFETs to step up the output voltage of the generator and a transistor provided for each MOSFET, which is set in an ON-state for a period during which a reverse voltage is applied to a parasitic diode of each MOSFET and set in an OFF-state for a period during which a forward voltage is applied to the parasitic diode of each MOSFET, wherein a control voltage for turning ON the MOSFET is given between the gate and source of the corresponding MOSFET for a period during which each transistor is in an OFF-state.