AC Power Detection Circuit for Abnormal Frequency Protection
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Solution Overview
Problem
Conventional power supply apparatuses lack effective alternating current (AC) power detection circuits, making them vulnerable to damage from abnormal AC power conditions, such as voltages below 90 volts or frequencies lower than 47 Hz.
Innovation Solution
A power supply apparatus comprising a main power processing circuit and an AC power detection circuit with a rectifying unit and a frequency processing unit, which rectifies AC power and detects its frequency, informing the main circuit to process the power only when the frequency is within the normal range (47 Hz to 63 Hz), thereby preventing damage from abnormal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power supply apparatus processes all AC power without detection, then the processing speed is fast and the device complexity is low, but the reliability deteriorates because the apparatus is damaged easily by abnormal AC power
Solution Approach 1:
The detection circuit is segmented into two independent functional units: a rectifying unit that converts AC to pulsating DC, and a frequency processing unit that detects frequency by comparing rectified voltage at different time points. This segmentation allows each unit to perform its specific function with simple circuitry, avoiding the need for a complex unified detection system while achieving reliable frequency detection to protect against abnormal AC power
Solution Approach 2:
The rectifying unit acts as an intermediary that converts the AC power signal into a form suitable for frequency detection. By rectifying the AC signal first, the frequency processing unit can detect frequency through voltage comparisons without needing to directly process the AC waveform, simplifying the detection mechanism while maintaining reliability
2Reliability
If the power supply apparatus adds a detection circuit to detect AC power frequency, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The frequency detection function is extracted from the main power processing circuit and implemented as a separate frequency processing unit. This unit only performs the specific task of frequency detection by sampling and comparing voltages, leaving the main power processing circuit unchanged. This extraction reduces the complexity burden on the overall system while achieving reliable detection
Solution Approach 2:
The frequency processing unit uses simple, inexpensive components that perform a single function (frequency detection) and can be easily replaced if needed. The unit employs basic voltage comparison logic rather than complex detection mechanisms, making the added complexity minimal and cost-effective while providing the necessary reliability improvement
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 effectively protects the power supply apparatus from damage by ensuring it only processes AC power within the normal frequency range, enhancing its reliability and longevity.
Implementation Method 1
The rectifying unit rectifies an alternating current power to obtain a rectified power
Data Source
AI summary
A power supply apparatus includes a main power processing circuit and an alternating current power detection circuit. The alternating current power detection circuit is electrically connected to the main power processing circuit. The alternating current power detection circuit includes a rectifying unit and a frequency processing unit. The rectifying unit is electrically connected to the main power processing circuit. The frequency processing unit is electrically connected to the main power processing circuit and the rectifying unit. The rectifying unit rectifies an alternating current power to obtain a rectified power. When a frequency of the rectified power is greater than a predetermined frequency, the frequency processing unit informs the main power processing circuit, so that the main power processing circuit processes the alternating current power to obtain an output direct current power.