Indirect Input Voltage Detection via Primary Winding Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional switching power converters face challenges in monitoring and protecting against brown-out conditions and loss of AC source, which can lead to thermal issues, component failure, and safety hazards due to the inability to accurately detect input voltage fluctuations without costly circuitry.
Innovation Solution
A system and method that indirectly detects input voltage by measuring current through the primary winding of a transformer, allowing the controller to generate control signals and detect conditions like brown-out or loss of AC source without a dedicated V_IN sense pin and ADC, using a transformer with a primary and secondary winding and a switch, and a controller that determines the input voltage based on primary current measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional voltage sensing circuitry (V_IN sense pin and ADC) is used to monitor input voltage, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent uses an intermediary approach by measuring primary current through the transformer winding instead of directly sensing input voltage. The current measurement serves as an indirect indicator of input voltage conditions, allowing the controller to detect brown-out and loss of AC source conditions without requiring dedicated voltage sensing circuitry.
Solution Approach 2:
The patent replaces the electrical voltage sensing system (V_IN sense pin and ADC) with a current measurement system. By measuring the primary current waveform characteristics, the system substitutes a simpler current sensing approach for the more complex voltage sensing architecture, reducing device complexity while maintaining detection capability.
2Reliability
If dedicated voltage sensing circuitry is implemented, then reliability of brown-out detection is improved, but manufacturing cost increases
Solution Approach 1:
The patent employs an intermediary measurement method where primary current serves as a proxy for input voltage monitoring. This approach achieves reliable brown-out detection by analyzing current waveform characteristics rather than requiring expensive dedicated voltage sensing hardware, thereby improving reliability while reducing manufacturing cost.
Solution Approach 2:
The patent utilizes existing, low-cost components (primary winding and current sensing capability) instead of expensive dedicated voltage sensing circuitry. By leveraging the transformer's primary winding as the sensing element, the system achieves reliable detection functionality using inexpensive, readily available components.
3Device complexity
If primary current measurement is used to indirectly detect input voltage, then device complexity is reduced, but measurement precision may be affected
Solution Approach 1:
The patent implements feedback by continuously monitoring primary current characteristics and using this information to infer input voltage conditions. The controller analyzes the current waveform and compares it against expected patterns to detect brown-out and loss of AC source conditions, maintaining measurement precision through intelligent signal processing of the current feedback.
Solution Approach 2:
The patent changes the measurement parameter from direct voltage sensing to current measurement. By measuring primary current instead of input voltage directly, the system achieves the same detection functionality with reduced complexity. The controller interprets current waveform parameters (magnitude, shape, continuity) to accurately determine input voltage conditions.
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
Enables real-time, accurate monitoring of input voltage without costly sensing devices, preventing damage from brown-out conditions and loss of AC source, and ensuring safety by allowing for appropriate power supply actions such as thermal shutdown or warning signals.
Implementation Method 1
a transformer coupled between an input and an output of the switching power converter, the transformer including a primary winding coupled to the input to receive an input voltage and a secondary winding coupled to output voltage
Data Source
AI summary
A power converter includes a transformer with a primary and a secondary winding and a switch. A controller of the power converter at the primary winding side of the transformer generates a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state. The controller determines current through the primary winding generated while the switch is turned on and indirectly detects an input voltage to the power converter based on the current through the primary winding generated while the switch is turned on. The controller in turn may detect conditions such as a loss of power or brown out at the input of the power converter based on the indirectly detected input voltage.