FET AC-DC Converter Using Negative Gate Pre-Charge
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Solution Overview
Problem
Conventional AC-to-DC converters require numerous circuit components, leading to signal processing delays, inaccuracies, and increased costs due to the use of transformer-based and switch mode power supply architectures.
Innovation Solution
A power converter circuit utilizing a first solid-state switch, a capacitor, and a control system that monitors voltage levels to regulate the switch's operation during AC power cycles, allowing efficient conversion to DC power by charging the capacitor during positive half-cycles and maintaining the switch off during negative half-cycles, with a Zener diode clamping the gate-to-source voltage for regulated threshold control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional transformer-based linear converter or switch mode power supply architecture is used, then AC-to-DC voltage conversion can be achieved, but the number of circuit components increases leading to signal processing delay, inaccuracy, and increased cost
Solution Approach 1:
The patent extracts and eliminates the transformer component from the conventional AC-to-DC converter architecture. By using a solid-state switch (FET) directly connected to the AC input without a transformer, the design achieves voltage conversion while reducing component count, signal processing delay, and cost, while maintaining conversion accuracy through precise gate control
Solution Approach 2:
The patent replaces the mechanical/magnetic transformer-based voltage transformation mechanism with an electronic solid-state switch (FET) controlled by gate voltage. This substitution eliminates the need for magnetic coupling and mechanical isolation, achieving voltage conversion through electronic switching and capacitance-based energy storage, thereby reducing complexity and improving response time
2Power
If numerous circuit components are used in conventional AC-to-DC converters, then voltage conversion function is achieved, but signal processing delay and inaccuracy increase
Solution Approach 1:
By removing the transformer and multiple switching components from the conventional architecture, the patent creates a minimal component design that reduces the number of signal transformation stages. The direct connection from AC input through a single FET to the output capacitor eliminates cumulative signal processing delays associated with multiple components
Solution Approach 2:
The patent applies a negative gate pre-charge voltage during the negative half-cycle of the AC input before the positive half-cycle begins. This preliminary action ensures the FET is fully off and ready for immediate turn-on when the positive half-cycle arrives, eliminating turn-on delay and ensuring rapid response to the input voltage change
3Reliability
If conventional diode bridge and switching regulator are used, then AC-to-DC conversion is achieved, but implementation cost increases
Solution Approach 1:
The patent merges the functions of the diode bridge rectifier, smoothing capacitor, and voltage regulator into a single integrated circuit implementation. By implementing the AC-to-DC converter as one monolithic chip with all necessary transistors, capacitors, and control logic integrated, the design eliminates the need for separate discrete components, reducing assembly complexity and manufacturing cost while maintaining voltage regulation performance
Solution Approach 2:
The patent designs a universal AC-to-DC converter that can handle various AC input voltages and frequencies without requiring different component configurations. The integrated circuit implements adaptive control that automatically adjusts to different input conditions, eliminating the need for manual component selection and reducing inventory complexity for manufacturers
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 reduces component complexity, minimizes signal processing delays, and enhances accuracy while maintaining a regulated DC voltage, suitable for intelligent electrical devices like solid-state circuit breakers and light dimmers.
Implementation Method 1
a first capacitor coupled between the second node and a ground reference node, and a control system configured to control operation of the first solid-state switch. The control system is configured to monitor a voltage level across the first capacitor and (i) turn on the first solid-state switch during a positive half-cycle of an AC power waveform coupled to the first node to cause charging current to flow from the first node to the second node and charge the first capacitor
Implementation Method 2
with a Zener diode clamping the gate-to-source voltage for regulated threshold control
Data Source
AI summary
A power converter circuit comprises a solid-state switch connected between first and second nodes, a capacitor coupled between the second node and a ground reference node, and a control system which monitors a voltage level across the capacitor and (i) turns on the solid-state switch during a positive half-cycle of an AC power waveform coupled to the first node to cause the capacitor to be charged, when the voltage level across the capacitor is less than a maximum DC voltage level, and (ii) turn off the solid-state switch during the positive half-cycle of the AC power waveform, in response to determining that the voltage level across the capacitor has reached the maximum DC voltage level. The control system is configured to generate a regulated threshold voltage for the solid-state switch during a negative half-cycle of the AC power waveform while maintaining the solid-state switch turned off during the negative half-cycle.