Ground Detecting Apparatus Using MOSFET and High Voltage Resistor
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Solution Overview
Problem
Current ground detecting and relay action detecting apparatuses rely on photo-couplers, which are costly, have low input impedance, and increase power consumption, as well as complicate printed circuit board layouts.
Innovation Solution
The proposed solution utilizes a diode unit, high voltage resistors, metal oxide semiconductor field effect transistors (MOSFETs), and controllers to generate a judgment voltage for determining the on-off state of the MOSFETs, reducing costs and power consumption, and incorporating Zener diodes for voltage protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photo-coupler is used for isolation in ground detecting apparatus, then isolation function is achieved, but cost increases
Solution Approach 1:
The patent extracts the isolation function from the photo-coupler and implements it separately using a capacitor connected between the neutral wire and ground wire. This separates the isolation requirement from the detecting apparatus circuitry, achieving isolation without using an expensive photo-coupler component.
Solution Approach 2:
The patent replaces the expensive photo-coupler with inexpensive passive components (capacitor, resistors, diodes) that can achieve the same isolation function. These simple components are much cheaper than photo-couplers while providing sufficient isolation for ground detection.
2Reliability
If a photo-coupler is used for isolation in ground detecting apparatus, then isolation function is achieved, but input impedance decreases
Solution Approach 1:
The patent removes the photo-coupler from the high-impedance measurement path and implements isolation elsewhere in the circuit. This extraction allows the input impedance to be determined by high-value resistors rather than being limited by the photo-coupler's low input impedance.
Solution Approach 2:
The patent changes the isolation implementation from an active photo-coupler component to a passive capacitive coupling method. This parameter change transforms the isolation mechanism while preserving high input impedance characteristics, as capacitors have negligible DC resistance.
3Reliability
If a photo-coupler is used for isolation in ground detecting apparatus, then isolation function is achieved, but power consumption increases
Solution Approach 1:
The patent replaces the power-consuming photo-coupler with passive components that consume negligible power. The capacitor-based isolation method and voltage divider circuit using high-value resistors draw minimal current, dramatically reducing power consumption compared to active photo-coupler operation.
Solution Approach 2:
The patent substitutes the electromagnetic opto-isolation mechanism of the photo-coupler with a passive electrical field-based isolation using capacitors. This substitution eliminates the need for light emission and detection processes that consume power, replacing them with field-based isolation that consumes minimal energy.
4Reliability
If a photo-coupler is used for isolation in ground detecting apparatus, then isolation function is achieved, but printed circuit board layout becomes difficult
Solution Approach 1:
The patent extracts the isolation function from the main signal path and implements it using simple parallel connections between existing circuit nodes (neutral wire and ground wire). This extraction eliminates the need for complex routing around photo-coupler components, simplifying PCB layout significantly.
Solution Approach 2:
The patent uses the existing neutral and ground wires in the power supply circuit to implement isolation, making these existing components serve multiple functions: power delivery and isolation reference. This multi-functionality eliminates the need for dedicated isolation component mounting areas, simplifying PCB design.
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 configuration reduces the cost and power consumption of ground and relay action detecting apparatuses, enhances input impedance, and simplifies printed circuit board layouts while ensuring reliable operation and safety.
Implementation Method 1
a diode unit, electrically connected to the alternating current power supply apparatus and configured to generate a direct current voltage
Implementation Method 2
a metal oxide semiconductor field effect transistor comprising a drain, a gate and a source; wherein the gate is electrically connected to the high voltage resistor and the first resistor
Implementation Method 3
The Zener diode clamps a judgment voltage to protect the metal oxide semiconductor field effect transistor to prevent the gate from excessive voltage
Data Source
AI summary
A ground detecting apparatus at least includes a metal oxide semiconductor field effect transistor and a high voltage resistor. The metal oxide semiconductor field effect transistor is used to replace a photo-coupler for switching. The high voltage resistor is used for safety isolation. A relay action detecting apparatus at least includes a metal oxide semiconductor field effect transistor and a high voltage resistor. The metal oxide semiconductor field effect transistor is used to replace a photo-coupler for switching. The high voltage resistor is used for safety isolation.