Zero-crossing detector power saving ceiling fan
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional zero-crossing detectors in ceiling fans continue to consume high power even when the fan is in sleep mode, preventing effective power-off protection during mains electricity loss.
Innovation Solution
A zero-crossing detector with a series configuration of a rectifier, an adjustor, and a feedback generator, which switches between a working state and a power-saving state based on a control signal, adjusting the current signal's magnitude to reduce power consumption and maintain functionality during sleep mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the AC voltage is continuously supplied to the zero-crossing detector, then the detector can generate pulse signals for control module operation, but the power consumption remains high during sleep mode
Solution Approach 1:
The patent applies dynamics by making the current path adjustable between different states. The adjustor dynamically changes the resistance value in the current path based on operating mode (working mode vs. sleep mode), allowing the system to adapt power consumption to actual needs while maintaining the ability to detect zero-crossing points and provide power-off protection.
Solution Approach 2:
The patent changes the resistance parameter in the current path to control power consumption. By adjusting the resistance value through the adjustor component, the system modifies the current flow characteristics to reduce power consumption during sleep mode while preserving the essential detection functionality for power-off protection.
2Use of energy by moving object
If the AC voltage supply is interrupted to reduce power consumption, then power consumption decreases, but the zero-crossing detector cannot generate pulse signals for control module operation
Solution Approach 1:
The patent applies partial action by providing just enough current through the adjusted resistance to maintain minimal detection functionality during sleep mode. The adjustor reduces but does not eliminate the current flow, allowing the detector to partially function for power-off protection while consuming significantly less power than continuous operation.
3Use of energy by moving object
If a high resistance is used in the current path to reduce power consumption, then power consumption decreases, but the current signal magnitude becomes insufficient for reliable detection
Solution Approach 1:
The patent uses dynamics by making the resistance adjustable rather than fixed. The adjustor allows the system to switch between low resistance (for accurate detection in working mode) and high resistance (for power saving in sleep mode), optimizing both detection accuracy and power consumption based on operational requirements.
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 power consumption in sleep mode while ensuring the detector can still learn the mains electricity condition and execute power-off protection procedures, enhancing energy efficiency and reliability.
Implementation Method 1
The rectifier performs half-wave rectification so that the current signal has a non-zero magnitude and flows from the first terminal along the current path to the second terminal when the AC voltage causes a potential at the first terminal to be greater than a potential at the second terminal, and has a zero magnitude when otherwise
Data Source
AI summary
A zero-crossing detector to be installed in a ceiling fan includes: a first terminal; a second terminal; and a rectifier, an adjustor and a feedback generator that cooperatively generate a current signal based on an AC voltage between the first and second terminals. The current signal has a non-zero magnitude when the AC voltage causes a potential at the first terminal to be greater than a potential at the second terminal, and has a zero magnitude when otherwise. An average of the non-zero magnitude of the current signal is greater when the adjustor is in a working state than when the adjustor is in a power saving state. The feedback generator generates a feedback signal based on the current signal.