Two-Terminal Current Controller for LED Lighting

The patent implements dynamic switching between series and parallel LED configurations based on the instantaneous AC voltage level. During high voltage periods, LEDs are connected in series to maximize brightness; during low voltage periods, they are reconfigured in parallel to maintain operation. This dynamic reconfiguration resolves the contradiction by allowing the system to adapt its electrical characteristics to match available voltage, thereby maintaining both high brightness capability and broad operational voltage range.

The patent replaces the passive resistive current limiting mechanism with an active electronic switching system using transistors and control circuits. Instead of using a resistor to drop excess voltage (which dissipates power as heat), the system uses solid-state switching elements to actively regulate current flow through the LEDs. This substitution eliminates the continuous power loss associated with resistive loading while maintaining current regulation functionality, thereby resolving the contradiction between circuit simplicity and energy efficiency.

The patent extracts and removes the large inductor and capacitor components from the circuit topology. Instead of using these bulky passive components for current regulation and voltage stabilization, the invention employs a fully solid-state switching architecture with small auxiliary capacitors and inductors. The current control function is achieved through PWM-based electronic switching and control logic rather than through large energy storage elements. This extraction of bulky components eliminates the power factor penalty associated with traditional AC-DC converter topologies while maintaining reliable current control.

The patent implements dynamic current regulation that adapts to the instantaneous voltage level rather than using a fixed turn-on threshold. The control circuit continuously monitors the AC voltage and adjusts the switching duty cycle to maintain appropriate current levels through the LEDs regardless of voltage variations. During high voltage periods, the system can operate at higher current levels; during low voltage periods, it automatically reduces current proportionally. This dynamic approach protects LEDs from overcurrent stress while utilizing the full available voltage range, resolving the contradiction between reliability and adaptability.