Bit Packer for LED Control Signal Bandwidth
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Solution Overview
Problem
Existing lamp control systems face challenges in achieving high-frequency bit rates for dimming and color changing LED lamps due to limited input bandwidth and electromagnetic compatibility issues, which conflict with the need for stable driver operation and human eye persistence requirements.
Innovation Solution
A bit packing arrangement that receives a binary control signal, counts off-bits and on-bits, and generates packets with variable lengths based on preselected values, outputting a packed control signal with a lesser average rate of change to stabilize driver operations and reduce electromagnetic compatibility issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a high-frequency binary control signal is used to control LED lamp brightness and color, then the lamp control responsiveness and color changing capability are improved, but electromagnetic compatibility issues worsen and driver stability deteriorates
Solution Approach 1:
The patent segments the high-frequency binary control signal into individual bit periods, counting the number of high bits and low bits within each period. By processing the signal at the bit level rather than as a continuous high-frequency waveform, the system achieves electromagnetic compatibility while preserving the original control information for LED brightness and color adjustment.
Solution Approach 2:
The patent introduces a bit packing arrangement as an intermediary device between the high-frequency control signal source and the LED driver. This intermediary counts and processes the binary signal bits, converting the high-frequency signal into a lower-frequency packet signal that drives the LED lamp, thereby eliminating electromagnetic compatibility issues while maintaining control functionality.
2Reliability
If a high bit rate control signal is used to avoid lamp flickering, then the human eye perceives steady light output, but the driver input bandwidth requirements increase and stability decreases
Solution Approach 1:
The patent performs preliminary action by counting the high and low bits within each bit period before generating the output packet signal. This preprocessing of the control signal allows the system to maintain the information content needed for steady light perception while reducing the output signal frequency to match the driver's bandwidth capabilities.
Solution Approach 2:
The patent changes the frequency parameter of the control signal from high-frequency (for flicker-free perception) to lower-frequency packet signals (for driver compatibility). By encoding the brightness and color information in the packet structure rather than in the signal frequency, the system achieves both flicker-free operation and driver stability.
3Speed
If the enable signal changes quickly to improve control responsiveness, then the lamp can respond faster to control commands, but the driver cannot stabilize at each input level
Solution Approach 1:
The patent segments the control signal into discrete bit periods with counted high and low bits. By processing complete bit periods and generating output packets based on these counts, the system ensures that the driver receives stable, well-defined signal levels for sufficient durations, allowing proper stabilization while still responding to rapid control command changes.
Solution Approach 2:
The patent uses periodic bit periods as the basis for control signal processing. Each bit period provides a stable, time-defined interval for counting and processing, ensuring that the driver receives periodic, stable signal levels that allow proper stabilization. The packet generation based on these periodic counts maintains control responsiveness without compromising driver stability.
Data Source
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AI summary
Representative implementations of devices and techniques provide a bit packing arrangement for a control signal. The control signal is received as a bit stream having a first rate of change. A packed control signal having a varying rate of change may be generated based on the bit stream. The average rate of change of the packed control signal is less than the first rate of change.