Inverter Frequency Switching for Lamp Stability
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Solution Overview
Problem
Conventional inverters can only activate lamps with a single working frequency, leading to issues such as flickering, waveform distortion, and uneven currents due to impedance matching problems during the transient period, resulting in insufficient luminance and shortened lamp life, especially as lamp dimensions increase.
Innovation Solution
An inverter capable of switching between two working frequencies: a lower frequency for the transient period and a higher frequency for the steady state, achieved through a voltage converter, feedback circuit, control unit, and frequency switcher that adjusts the resonance circuit's impedance after a predetermined period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single working frequency is used for the lamp, then the device complexity is reduced, but the lamp performance deteriorates due to impedance matching problems in different working states
Solution Approach 1:
The patent applies dynamics by making the working frequency adjustable rather than fixed. The inverter switches between a first working frequency during transient period and a second working frequency during steady state, allowing the system to adapt to changing lamp conditions and achieve optimal performance in each phase
Solution Approach 2:
The patent changes the frequency parameter of the AC voltage output based on the lamp's working state. By switching between different frequency values (first working frequency and second working frequency), the system optimizes lamp activation and steady-state operation without requiring complex circuit redesign
2Illumination intensity
If the working frequency suitable for steady state is selected, then the lamp luminance is improved, but the waveform stability deteriorates during the transient period
Solution Approach 1:
The patent applies preliminary action by using the first working frequency during the transient period before steady state is reached. This preliminary frequency selection ensures stable waveform during activation, preventing flickering and preparing the lamp for optimal steady-state operation with the second working frequency
3Stability of the object's composition
If the working frequency suitable for transient period is selected, then the waveform stability is improved, but the lamp luminance deteriorates after the transient period
Solution Approach 1:
The patent dynamically switches the working frequency based on the lamp's operational phase. After the transient period when waveform stability is established with the first frequency, the system transitions to the second working frequency to optimize luminance and prevent issues like waveform distortion and uneven currents
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 inverter ensures optimal lamp performance in both transient and steady states by providing suitable frequencies, preventing flickering and waveform distortions, thus improving luminance and extending lamp life.
Implementation Method 1
The control unit 140 includes a resonance circuit 142 and a control device 144. The resonance circuit 142 includes a resonance capacitor Ct and a resonance resistor Rt. The control unit 140 can generate a working frequency according to the resonance resistor Rt and the resonance capacitor Ct.
Implementation Method 2
The transformer 114 receives the first AC voltage, transforms the first AC voltage into a second AC voltage, and then outputs the second AC voltage to a lamp 600.
Implementation Method 3
The lamp 600 requires different working frequencies in different working states. For example, at a transient period after the inverter 100 initially activates the lamp 600, the gas and the metal elements in the lamp 600 are activated but not stable.
Data Source
AI summary
An inverter capable of switching working frequency for activating a lamp. The inverter comprises a voltage converter, a feedback circuit, a control unit and a frequency switcher. The voltage converter transforms a DC input voltage into a second AC voltage according to a control signal. The lamp is activated and generates a feedback current. The circuit converts the feedback current into the feedback voltage. The control unit for generating a first working frequency includes a resonance circuit having a specific resistance and capacitance, and a control device for generating the control signal according to a reference voltage, the first working frequency and the feedback voltage in a predetermined period. Then, the switcher changes the specific resistance and/or capacitance for enabling the control unit to generate a second working frequency. The control device outputs the control signal according to the second working frequency and the feedback voltage.