PWM Signal Generator Phase Inversion for Power Supply Noise
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Solution Overview
Problem
Conventional lighting control techniques using pulse width modulation (PWM) signals lead to increased differences between maximum and minimum supply power in power supply devices, shortening component life and generating noise.
Innovation Solution
A PWM signal generator comprising a first comparison unit, a signal inversion unit, and a reference wave generator, which compares input duty values to a reference wave to generate non-overlapping PWM signals, reducing power differences and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PWM signal generation is used for controlling multiple lights, then lighting control is achieved, but the difference between maximum and minimum supply power increases, shortening component life and generating noise
Solution Approach 1:
The patent inverts the phase relationship between PWM signals by using a signal inversion unit that subtracts the duty value from the maximum reference wave value. This creates complementary PWM signals where one signal is high when the other is low, preventing overlapping high-power periods and reducing the peak-to-average power difference in the power supply device.
Solution Approach 2:
The patent uses periodic reference waves (sawtooth or triangle waves) to generate PWM signals with controlled duty cycles. By synchronizing multiple PWM signals with the same periodic reference wave and applying phase inversion, the system creates a periodic pattern where power consumption is distributed more evenly over time, reducing the maximum power difference.
2Object-affected harmful factors
If conventional PWM signal generation is used for controlling multiple lights, then lighting control is achieved, but noise and electromagnetic interference are generated
Solution Approach 1:
By inverting the phase of PWM signals through the signal inversion unit, the patent ensures that when one light channel draws high power, the other channel draws low power. This phase inversion strategy distributes the electromagnetic interference and noise generation more evenly over time, preventing concentrated noise bursts that occur with conventional overlapping PWM signals.
3Ease of operation
If PWM signals are generated for each light, then individual light control is achieved, but overlapping PWM sections cause power supply device components to deteriorate
Solution Approach 1:
The signal inversion unit creates complementary PWM signals by subtracting the duty value from the maximum reference value. This ensures that individual light control is maintained through duty cycle adjustment while the inverted phase relationship prevents overlapping high-power sections, thereby protecting power supply components from excessive stress and extending their lifespan.
Data Source
AI summary
A pulse width modulation (PWM) signal generator according to one embodiment of the present invention includes a first comparison unit for comparing a duty value being inputted with a reference wave being inputted to output a first PWM signal, a signal inversion unit for inverting the duty value being inputted on the basis of a maximum value of the reference wave, a second comparison unit for comparing the duty value inverted by the signal inversion unit with the reference wave being inputted to output a second PWM signal, and a reference wave generator for generating a reference wave to transmit the same to each of the first comparison unit and the second comparison unit.