Power Supply Over-Voltage Protection via Voltage Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power supplying apparatuses are vulnerable to damage from over-voltage and over-current due to user errors or component degradation, particularly when handling input voltages of 220V, which can lead to capacitor damage and potential explosions in MOSFETs.
Innovation Solution
A power supplying apparatus with a rectifying part, smoothing part, voltage selecting part, transforming part, and protection mechanisms that estimate voltage and current levels, suspending output operations if predetermined values are exceeded, using resistors, zener diodes, and comparators to prevent over-voltage and over-current from reaching sensitive components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the voltage selector is closed to double the input voltage for 110V input, then the output voltage is increased to match 220V requirements, but the capacitors may be damaged due to excessive voltage (1.4 times 220V) being applied
Solution Approach 1:
The patent applies preliminary action by detecting the input voltage magnitude before the voltage doubling operation is performed. The detection circuit measures whether the input voltage is 110V or 220V, and only enables the voltage doubling path (closing the voltage selector) when 110V is detected. This prevents the harmful condition where 220V input would incorrectly trigger voltage doubling, thereby protecting the capacitors from excessive voltage stress.
Solution Approach 2:
The patent implements feedback through a detection circuit that continuously monitors the input voltage magnitude and provides feedback to control the voltage selector state. The detection result feeds back to the control logic, which adjusts the voltage selector accordingly. This closed-loop feedback mechanism ensures that the voltage doubling function is activated only under appropriate conditions, preventing over-voltage damage to capacitors while maintaining reliable output voltage.
2Ease of operation
If the voltage selector is closed due to user mistake or erroneous operation, then the voltage doubling function is activated, but over-current may result in the MOSFET potentially causing an explosion
Solution Approach 1:
The patent applies preliminary action by performing input voltage detection before enabling the voltage doubling path. The detection circuit assesses whether the input voltage magnitude warrants voltage doubling, and only then allows the voltage selector to be closed. This preliminary check prevents erroneous activation of voltage doubling even if the user mistakenly sets the selector, thereby preventing over-current conditions that could damage the MOSFET.
Solution Approach 2:
The patent implements feedback by using the detection circuit to monitor input voltage and feed this information back to control the voltage selector and MOSFET operation. The feedback mechanism ensures that the MOSFET is activated for voltage doubling only when the input voltage magnitude is appropriate (110V). This prevents harmful over-current flow through the MOSFET even if the voltage selector is incorrectly positioned, thereby protecting against MOSFET failure.
3Reliability
If PWM controller IC degrades causing gate on time problem in MOSFET, then the MOSFET may be damaged, but adding protection circuits increases system complexity
Solution Approach 1:
The patent applies preliminary action by implementing input voltage detection before the MOSFET is activated. The detection circuit determines whether the input voltage magnitude is appropriate for voltage doubling operation, and only then enables the MOSFET. This preliminary check prevents MOSFET activation under inappropriate conditions (such as when PWM controller IC has degraded), thereby protecting the MOSFET without requiring complex real-time monitoring circuits.
Solution Approach 2:
The patent uses an intermediary detection circuit that mediates between the input voltage and the MOSFET activation. This intermediary circuit assesses the input voltage magnitude and controls whether the MOSFET should be activated for voltage doubling. By placing this intermediary detection layer, the patent simplifies the protection mechanism compared to complex real-time MOSFET monitoring circuits, while still effectively preventing MOSFET damage from PWM controller degradation or other anomalies.
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 apparatus effectively protects against over-voltage and over-current, preventing damage to capacitors and MOSFETs by interrupting current flow and voltage application, ensuring stable operation and extending component lifespan.
Implementation Method 1
a rectifying part rectifying an input alternating current to output a direct current
Implementation Method 2
The smoothing part 15 includes capacitors 15a and 15b that correspond to the input power 11 of 110V and 220V, for example, and charges energy of the current rectified by the rectifying part 12 into each capacitor 15a and 15b
Implementation Method 3
a smoothing protection part estimating the magnitude of the smoothed voltage and suspending the direct current output from the rectifying part if the estimated magnitude of the voltage is determined to be more than a predetermined voltage value
Data Source
AI summary
A power supply operable from a plurality of alternating current inputs had having protection from abnormal operation. The power supply includes a switchable rectifier and a voltage to voltage converter. Protection circuits switch off at least one of the rectifier and the converter if the rectified voltage exceeds a predetermined voltage value and/or a current through the converter exceeds a predetermined current value. The protection circuits include latch circuits to prevent cyclic operation.