LED Driving Apparatus Sine Wave Current Control
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Solution Overview
Problem
Existing LED driving apparatuses that use AC power require large and power-consuming AC-DC converters, which negate the advantages of LEDs such as high efficiency and long lifespan, and suffer from poor power factor and total harmonic distortion due to step-type current waveforms.
Innovation Solution
A light emitting diode (LED) driving apparatus that includes a switching unit, a driving control unit, a current limiting unit, and an adjusting unit to control the current flowing to LEDs, ensuring the current waveform follows a sine wave, thereby improving power factor and total harmonic distortion characteristics without the need for an AC-DC converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a general AC-DC converter is used to drive LED with AC power, then the LED can be driven using commercial AC power, but the apparatus becomes large in volume and consumes significant power
Solution Approach 1:
The patent extracts and eliminates the bulky AC-DC converter from the traditional LED driving apparatus architecture. By directly connecting the LED array to the AC power supply through a switching unit controlled by a driving control unit, the invention removes the intermediate conversion stage that caused volume and power consumption issues, while still enabling AC power operation.
Solution Approach 2:
The switching unit and driving control unit serve multiple functions: they control LED switching, regulate current flow, and enable direct AC power operation without requiring separate AC-DC conversion circuitry. This multi-functionality eliminates the need for dedicated AC-DC converter components.
2Adaptability or versatility
If a general AC-DC converter is used to drive LED with AC power, then the LED can be driven using commercial AC power, but the apparatus consumes significant power
Solution Approach 1:
The patent extracts and eliminates the power-consuming AC-DC converter from the traditional LED driving apparatus architecture. By directly connecting the LED array to the AC power supply through a switching unit controlled by a driving control unit, the invention removes the intermediate conversion stage that caused volume and power consumption issues, while still enabling AC power operation.
Solution Approach 2:
The switching unit operates by periodically switching on and off according to the AC power cycle, creating a square wave current waveform that follows the AC power frequency. This periodic switching action enables direct AC power operation without requiring continuous power conversion, reducing overall power consumption.
3Adaptability or versatility
If switches are controlled according to AC power level to allow uniform current flow, then LED can be directly driven with AC power, but the current waveform becomes step-type which deteriorates power factor and total harmonic distortion
Solution Approach 1:
The patent applies dynamics by making the switching control adaptive to the instantaneous AC power voltage level. The driving control unit dynamically adjusts the switching timing based on the AC power waveform, transitioning from fixed step-type control to dynamic voltage-level-dependent control. This enables the current waveform to follow the sine wave shape of the AC power, improving power factor and reducing harmonic distortion.
Solution Approach 2:
The patent changes the control parameter from fixed switching timing to variable switching timing based on AC power voltage levels. By adjusting the switching moment according to the instantaneous voltage level of the AC power supply, the system transforms the step-type current waveform into a sine-wave-following waveform, thereby improving power factor and reducing total harmonic distortion.
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 solution achieves improved power factor and reduced total harmonic distortion by ensuring the current waveform follows the sine wave of the rectified AC power, enhancing the efficiency and lifespan of LEDs while eliminating the need for bulky AC-DC converters.
Implementation Method 1
A light emitting diode (LED) is a semiconductor element having a p-n junction structure and emitting light through electron-hole recombination
Implementation Method 2
a rectifying unit rectifying alternating current (AC) power to supply the rectified power to at least one pair of the LEDs
Data Source
AI summary
There is provided a light emitting diode (LED) driving apparatus configured such that a waveform of current input to an LED follows a sine wave, the LED driving apparatus including, a switching unit switching an LED unit having a plurality of LEDs receiving rectified power and emitting light, a driving control unit controlling the switching of the switching unit according to a voltage level of the rectified power, a current limiting unit limiting current flowing in the LED unit, and an adjusting unit adjusting current limitation of the current limiting unit according to the voltage level of the rectified power.