Parallel MOSFET Light Dimmers With Alternating Switching Loss
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Solution Overview
Problem
Existing methods for operating multiple light dimmers in parallel result in bulky devices due to uneven energy dissipation and switching losses, which are concentrated in the last dimmer when interrupting the circuit.
Innovation Solution
A method where two or more light dimmers, with MOSFET transistors, are synchronized to alternately open and close their transistors within each current half-period, distributing switching energy and reducing the size of the dimmers by ensuring that each dimmer handles a portion of the switching energy, with a master-slave configuration for synchronization and voltage supervision to maintain stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple dimmers are connected in parallel to drive high-power light loads, then the power handling capability is improved, but the switching energy is always dissipated in the last dimmer which opens its transistor, causing increased energy loss and device size
Solution Approach 1:
The patent implements periodic alternation of the opening sequence between master and slave dimmers across successive half-cycles. In one half-cycle, the slave dimmer opens first followed by the master dimmer; in the next half-cycle, the master dimmer opens first followed by the slave dimmer. This periodic reversal ensures that switching energy dissipation is distributed alternately between the two dimmers, preventing continuous energy loss in a single device and enabling both dimmers to be designed with smaller, more efficient components.
2Power
If multiple dimmers are connected in parallel to drive high-power light loads, then the power handling capability is improved, but the variators become particularly bulky
Solution Approach 1:
By periodically alternating which dimmer opens last (and thus dissipates switching energy) in successive half-cycles, the patent enables both master and slave dimmers to operate under balanced thermal and electrical stress conditions. This allows each dimmer to be designed with optimized, smaller-sized components rather than requiring oversized components to handle the full switching energy burden, thereby reducing the overall volume of the dimming system while maintaining high-power capability.
3Ease of operation
If the transistor of the first dimmer is opened after the second dimmer in every cycle, then the control simplicity is improved, but the switching energy is always dissipated in the first dimmer, causing uneven energy distribution
Solution Approach 1:
The patent maintains control simplicity through a standardized sequence (slave opens first, then master) while introducing periodic reversal of the overall sequence alternation. In odd half-cycles, the sequence is slave→master; in even half-cycles, it is master→slave. This approach preserves the ease of implementing a fixed control sequence within each half-cycle while achieving balanced energy dissipation across cycles, combining operational simplicity with equitable energy distribution.
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
This approach results in compact, high-power light dimmers that minimize energy loss and flickering, allowing for the use of smaller, more efficient MOSFET transistors and reducing the overall size of the dimmer assembly while maintaining stable light control.
Implementation Method 1
Each of the drives comprises at least one transistor, preferably a transistor of the MOSFET type. In a first time interval, each of the transistors of the dimmers is closed so as to turn on the light source. In a second time interval, each of the transistors of the dimmers is opened so as to turn off the light source.
Implementation Method 2
During the first time interval, the energy dissipated due to the ohmic resistance of the various drives can be distributed over each of the drives. In addition to the energy dissipated due to the ohmic resistance of the drives, part of the electrical energy is lost due to switching energy which occurs when an electrical circuit is interrupted.
Data Source
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AI summary
The present invention relates to a method for operating a set of at least two light dimmers, called first dimmer, preferably master dimmer, and second dimmer, preferably slave dimmer, connected in parallel between a current source and a light source, each dimmer comprising at least one transistor, preferably of the MOSFET type, method in which, in a first time interval, each of the transistors of the dimmers is closed so as to turn on the light source, and in which, in a second time interval, each of the transistors of the dimmers is open so as to turn off the light source.A method characterized in that, from at least two consecutive cycles, namely a first cycle and a second cycle, in the first cycle, between the first time interval and the second time interval, the transistor of the first variator is opened after the opening of the transistor of the second variator, and in that, in a second cycle, between the first time interval and the second time interval, the transistor of the second variator is opened after the opening of the transistor of the first variator.