Visible Light Communication Device Modulation Rate Adjustment
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Solution Overview
Problem
Existing visible light communication devices have a fixed modulation rate, making it difficult to change the modulation rate without replacing components, which is inconvenient for installations or design changes in lighting systems.
Innovation Solution
A visible light communication device with a variable impedance circuit and controllers that allow for easy adjustment of the modulation rate by changing the impedance of the circuit based on voltage, current, or ambient light measurements, using components like MOSFETs or bipolar transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed resistor is used as the load change element, then the circuit structure is simple, but the modulation rate cannot be changed easily
Solution Approach 1:
The patent applies the Dynamics principle by replacing the fixed resistor with a variable impedance circuit that can dynamically adjust its resistance value. The load change element is implemented using a switching device (such as MOSFET or bipolar transistor) whose on-resistance can be controlled to provide different impedance values, enabling easy modulation rate adjustment without circuit restructuring.
Solution Approach 2:
The patent applies the Parameter changes principle by changing the resistance parameter of the load change element from a fixed value to a variable value. The variable impedance circuit allows the resistance to be adjusted between different states (high impedance when off, low impedance when on), thereby changing the electrical parameters of the circuit to achieve different modulation rates.
2Adaptability or versatility
If a fixed resistor is used as the load change element, then the manufacturing cost is low, but component replacement is required for design changes
Solution Approach 1:
The patent applies the Dynamics principle by implementing a variable impedance circuit using active switching devices that can be controlled through software or control signals. This dynamic approach allows the same hardware to adapt to different design requirements by changing control parameters rather than replacing physical components, thereby improving design flexibility without significantly increasing manufacturing complexity.
Solution Approach 2:
The patent applies the Universality principle by designing a load change element that can serve multiple functions: it acts as a variable resistor for modulation rate adjustment, can be controlled through digital signals, and can adapt to different lighting system configurations. This multi-functional design reduces the need for specialized components for each application scenario.
Data Source
AI summary
A variable impedance circuit (2) has an impedance device and is connected in series with a light source (A1). A switch circuit (Q1) is connected in parallel with the variable impedance circuit (2). A first controller (3) is configured to perform ON and OFF control of the switch circuit (Q1) and thereby to modulate an intensity of an illumination light emitted from the light source (A1). An impedance-varying circuit (Q2) is connected with the variable impedance circuit (2). The second controller (4) is configured to control the impedance-varying circuit (Q2) to change the impedance of the variable impedance circuit (2). The first controller (3) and the second controller (4) share a common hardware.