US Pat. No. 10,757,774

CURRENT ADJUSTMENT CIRCUIT

MAXIC TECHNOLOGY CORPORAT...

1. A current adjustment circuit, wherein:the current adjustment circuit comprises a lighting sub-circuit, a dimming switch, a switch control sub-circuit connected to the dimming switch and the lighting sub-circuit, and a time control sub-circuit connected to the switch control sub-circuit;
the time control sub-circuit is configured to determine a first preset time period and a second preset time period, wherein
in the first time period, the current adjustment circuit is in a first state and current flow of the lighting sub-circuit is oscillating around zero and/or hold at zero;
in the second time period, the current adjustment circuit is in a second state and the current flow of the lighting sub-circuit is larger than zero; and
the dimming switch is configured to control the current adjustment circuit to switch from the first state to the second state by switching from a switch-off state to a switch-on state.

US Pat. No. 10,952,293

CURRENT ADJUSTMENT CIRCUIT

MAXIC TECHNOLOGY CORPORAT...

1. A circuit for adjusting current, the circuit comprising:a dimming switch coupled to an inductor disposed in a lighting sub-circuit, wherein the dimming switch is configured to control power supply states of the inductor;
a zero-crossing detector configured to detect an ending time of a current of the inductor, and to generate a zero-crossing signal; and
a time control sub-circuit including a first capacitor and a second capacitor and configured to receive the zero-crossing signal, and to generate a control signal that is configured to control the dimming switch to initiate a switching cycle for the inductor; wherein the switching cycle starts after a delay time, and the delay time is controlled by a first charging time of the first capacitor and a second charging time of the second capacitor.

US Pat. No. 11,071,179

DIMMABLE LED DRIVE CIRCUIT AND CONTROL METHOD THEREOF

MAXIC TECHNOLOGY CORPORAT...


1. A dimmable LED drive circuit, comprising:an LED circuit configured to emit light;
a thyristor dimmer configured to control a voltage waveform applied to the LED circuit, the voltage waveform including a chopping angle corresponding to an initial conduction of the thyristor dimmer;
a bleeder current circuit configured to provide a current path for the thyristor dimmer to maintain a conduction of the thyristor dimmer;
a thyristor chopping angle detection circuit configured to detect at least one parameter associated with the chopping angle of the voltage waveform applied to the LED circuit;
a bleeder current control circuit configured to control an operation of the bleeder current circuit based on an operation of the LED circuit and the at least one parameter associated with the chopping angle; and
an output current compensation circuit configured to reduce a current flowing through the LED circuit when a voltage corresponding to the chopping angle is close to a forward voltage of the LED circuit.