LED Driver Voltage Sensing Around Current Debounce Windows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light driving devices erroneously sense a light emitting diode in a normal state as an abnormal state, such as a short or open state, due to voltage sensing errors at the start point where current is applied or at the end point where current is blocked.
Innovation Solution
A light driving apparatus that includes a light part, a first sensing part for input current, a second sensing part for output voltage, and a control part that starts voltage sensing after a first de-bouncing time has elapsed from the start point and stops sensing before a second de-bouncing time from the end point, thereby preventing erroneous state detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage sensing is performed continuously during current supply and block sections, then abnormal states can be detected, but voltage sensing errors occur during voltage bouncing periods causing erroneous detection
Solution Approach 1:
The control device determines a voltage bouncing period before performing voltage sensing. By identifying the time period when voltage bouncing occurs (during current supply or block sections) and excluding it from sensing operations, the device prevents erroneous detection. This preliminary identification of the problematic time period resolves the contradiction by ensuring voltage sensing is performed only when stable voltage conditions exist.
2Speed
If voltage sensing is performed at all times, then system response is fast, but erroneous sensing occurs during voltage transitions
Solution Approach 1:
The control device preliminarily determines the voltage bouncing period based on timing information from current supply and block sections. By pre-identifying when voltage instability will occur, the device can skip sensing during these periods and resume sensing immediately afterward, maintaining fast response while avoiding erroneous detection during transitions.
Solution Approach 2:
The device converts the harmful effect of voltage bouncing into a beneficial timing reference. By using the known duration and timing of current supply and block sections to calculate the voltage bouncing period, the device transforms a source of error into a useful parameter for optimizing sensing timing, thereby improving both reliability and response speed.
Data Source
AI summary
A light driving apparatus according to an embodiment includes a light part; a first sensing part configured to sense an input current value of the light part; a second sensing part configured to sense an output voltage value of the light part; and a control part configured to sense the output voltage value through the second sensing part based on the input current value sensed through the first sensing part and determine a state of the light part based on the output voltage value; wherein the control part is configured to start a sensing operation of the output voltage value through the second sensing part after a first de-bouncing time has elapsed from a start point in which current is applied to the light part, and stop the sensing operation of the output voltage value through the second sensing part before a second de-bouncing time from an end point at which the current applied to the light part is blocked.