Light State Regulation Controller Using PWM Signal Detection
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Solution Overview
Problem
Existing light state regulation control systems for lamps require additional components for switch state sampling, increasing costs and potentially causing false actions due to the impact of capacitors on voltage discharge times.
Innovation Solution
A light state regulation controller comprising a peak current comparator, PWM controller, power switch, state detector, and state machine, which eliminates the need for switch state sampling components and uses PWM signals to control LED lightness, enabling quick response to switch state changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional components are added for switch state sampling, then the control system can detect switch states, but system costs increase
Solution Approach 1:
The patent extracts the switch state detection function from a separate sampling circuit and integrates it into the existing PWM control signal path. The state detector uses the PWM control signal itself to derive switch state information, eliminating the need for separate sampling components like diodes, resistors, and capacitors that were previously required.
Solution Approach 2:
The PWM control signal serves dual purposes: it controls the power switch and simultaneously provides the basis for detecting switch state changes. The state detector and state machine process this existing signal to generate state control signals, making the system multi-functional without adding components.
2Stability of the object's composition
If an X capacitor is added before the rectifier bridge, then voltage filtering is improved, but discharge time constant increases causing false switch actions
Solution Approach 1:
The patent performs preliminary detection of the PWM control signal state before the capacitor discharge effect can cause false readings. By detecting switch state changes directly from the PWM signal edges, the system acts before the capacitor voltage decay could mask the actual switch state, preventing false actions.
Solution Approach 2:
The state detector acts as an intermediary that translates PWM control signal edges into reliable state control signals. This intermediary process occurs independently of the capacitor discharge timing, ensuring accurate switch state detection regardless of the capacitor's voltage keeping effect.
Data Source
AI summary
The present disclosure provides a light state regulation controller, control system and control method. The controller comprises a peak current comparator, a PWM controller, a power switch, a state detector and a state machine. The peak current comparator produces a PWM turn-off signal according to a comparison result between a peak current sampling signal and a reference voltage. The PWM controller outputs a PWM control signal and the reference voltage under the control of the PWM turn-off signal and a state control signal, wherein the state control signal controls the state of the PWM control signal. The state detector detects a state change in the PWM control signal or an equivalent signal for the PWM control signal, and outputs a state input signal. The state machine produces a plurality of states according to the state input signal, and outputs the state control signal reflecting the plurality of states.