LED Driver Circuit with Dynamic Damping Resistor Control
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Solution Overview
Problem
Existing LED illumination systems using TRIAC phase-cut dimmers suffer from power loss and reduced service lifetime due to high-power damping resistors, and dynamic switches fail to recognize dimmer connections, leading to inefficient power management.
Innovation Solution
An illumination control system with a recognizing control circuit that includes a voltage sampling device, phase-cut angle detecting device, and switch module to determine the dimmer's connection state and control the damping resistor's operation, reducing unnecessary power consumption by short-circuiting the damping resistor when not needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-power damping resistor is used to inhibit flickering in LED illumination systems with TRIAC phase-cut dimmers, then flickering is suppressed, but power loss increases by 3%-5% and service lifetime is reduced
Solution Approach 1:
The patent applies dynamics by making the damping resistor's connection state changeable rather than fixed. A control circuit dynamically switches the damping resistor between connected and disconnected states based on whether a dimmer is detected in the circuit. When no dimmer is present or dimming level is sufficient, the damping resistor is disconnected to eliminate power loss. When dimmer-induced flickering is detected, the damping resistor is connected to suppress flicker, thus resolving the contradiction between flicker suppression and power loss.
2Loss of energy
If a dynamic switch is used to reduce power loss on the damping resistor, then power loss is reduced, but the system cannot recognize dimmer connection status, causing the damping resistor to remain operational unnecessarily
Solution Approach 1:
The patent implements feedback by using a control circuit that continuously monitors the circuit status to detect whether a dimmer is connected and at what dimming level. The control circuit receives feedback signals from the circuit configuration and uses this information to intelligently control the switching of the damping resistor. This feedback mechanism enables the system to adapt to different operating conditions, connecting the damping resistor only when necessary for flicker suppression while disconnecting it during normal operation to minimize power loss.
3Reliability
If the damping resistor remains in operation state continuously, then flicker is suppressed, but the driving power of the LED system is reduced
Solution Approach 1:
The patent applies periodic action by implementing intermittent operation of the damping resistor rather than continuous operation. The control circuit periodically assesses the circuit conditions and activates the damping resistor only during periods when dimmer-induced flickering is detected. During normal operating periods without dimmer interference, the damping resistor remains disconnected, allowing the LED system to operate at full driving power while still providing flicker suppression when needed.
Data Source
AI summary
An illumination control system includes a rectifying device, a damping device for inhibiting flickering, and a load circuit, wherein the illumination control system further comprises a recognizing control circuit connected between the rectifying device and the damping device, and wherein the recognizing control circuit includes a recognizing signal output module and a switch module, the recognizing signal output module generates a first control signal indicating that a dimmer is not connected upstream the rectifying device or the dimmer is connected upstream the rectifying device and reaches a predetermined dimming level and a second control signal indicating that the dimmer is connected upstream the rectifying device and does not reach the predetermined dimming level and at least one damping resistor of the damping device is short connected or is connected by means of the switch module according to the first control signal or the second control signal.