Integrated Bleeder Circuit for Dimmer AC Switch Commutation
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Solution Overview
Problem
Existing dimmers face challenges when controlling light non-linear loads, such as LED lamps, due to issues like overshoot and flicker, which result in undesirable performance and increased complexity and cost, particularly because prior bleeder circuits require external components and are not effectively synchronized with the dimmer's AC switch.
Innovation Solution
A bleeder circuit integrated within the dimmer that uses the internal switching signal of the main AC switch to enable a bleeder load, ensuring correct commutation and reducing complexity and cost by eliminating the need for external components, with a bleeder load that dissipates power only when necessary, utilizing components like PTC thermistors for safety and a differentiator circuit to synchronize the bleeder load with the dimmer's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a prior art bleeder circuit is used with external components, then operational assistance to the AC switch is provided, but device complexity and cost increase
Solution Approach 1:
The patent merges the bleeder circuit with the dimmer by integrating the bleeder load into the existing AC switch structure. The bleeder load is connected in parallel with the AC switch and is controlled by the same trigger signal, eliminating the need for separate external bleeder components and reducing overall device complexity while maintaining reliable AC switch commutation.
Solution Approach 2:
The AC switch structure is designed to serve dual functions: switching the main load and providing bleeder functionality through the integrated bleeder load. This multi-functional design allows a single component structure to perform multiple tasks, reducing the total number of components needed and simplifying the overall circuit architecture.
2Reliability
If a prior art bleeder circuit is used with external components, then operational assistance to the AC switch is provided, but manufacturing cost increases
Solution Approach 1:
The patent combines the bleeder load and dimmer into a single integrated unit, reducing the number of separate components that need to be manufactured and assembled. This integration simplifies the manufacturing process and reduces assembly steps, thereby lowering manufacturing costs while ensuring reliable AC switch commutation.
Solution Approach 2:
The integrated design allows the dimmer assembly to perform both dimming and bleeder functions simultaneously, eliminating the need for separate bleeder circuit assembly. This multi-functional approach reduces manufacturing complexity and cost while maintaining reliable operation.
3Reliability
If the bleeder load is continuously enabled, then operational assistance is always available, but power dissipation increases
Solution Approach 1:
The bleeder load is enabled periodically through a trigger circuit that generates trigger pulses synchronized with the AC cycle. The trigger signal enables the bleeder load only during specific phases of the AC waveform when operational assistance is needed for AC switch commutation, rather than keeping it continuously enabled, thereby reducing unnecessary power dissipation while maintaining reliable AC switch operation.
Solution Approach 2:
The bleeder load impedance is dynamically adjusted through the trigger circuit, which controls the conduction angle of the bleeder load. By varying the conduction angle according to the AC cycle phase, the system provides operational assistance only when needed and reduces power dissipation during periods when assistance is not required, achieving a dynamic balance between reliability and energy efficiency.
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 effectively eliminates zero-crossing overshoot, reduces power dissipation, and simplifies the dimmer design by integrating the bleeder circuit, allowing for efficient dimming of light non-linear loads without the need for external bleeder components, thereby enhancing system performance and reducing costs.
Implementation Method 1
utilizing components like PTC thermistors for safety
Implementation Method 2
a differentiator circuit to synchronize the bleeder load with the dimmer's operation
Data Source
AI summary
The invention describes a bleeder circuit (1) realized for use in a dimmer (2) comprising a main AC switch (20) for switching a supply voltage (LINE) to a light non-linear load (L), which bleeder circuit (1) comprises a bleeder load (11) realized to provide operational assistance to main AC switch (20); wherein the bleeder load (11) is enabled on the basis of a switching signal (T20) of the main AC switch (20). The invention further describes a dimmer (2) comprising such a bleeder circuit (1). The invention also describes an electrical appliance comprising a light non-linear load (L) and such a dimmer (2). The invention further describes a method of dimming a light non-linear load (L).