A dimming regulated power supply module comprising a control circuit, a voltage-stabilizing circuit, a dimming circuit, and an output port, wherein the control circuit converts city power into a supply voltage for supplying power to a LED light string through the output port, wherein the voltage-stabilizing circuit senses an internal voltage of the control circuit to generate a first voltage and a second voltage, and supplies power to a single-chip microcomputer in the dimming circuit after stabilizing the second voltage, wherein the voltage-stabilizing circuit outputs the first voltage to set the voltage range of the dimming circuit, wherein the output port transmits the dimming signal output by a dimmer to the dimming circuit, and wherein the dimming circuit generates a corresponding pulse-width modulation signal, wherein the control circuit controls the supply current according to the pulse-width modulation signal, thereby controls the brightness of the LED light string through the output port.

An LED tube lamp includes a lamp tube, a heat shrink sleeve covering on an outer surface of the lamp tube, an LED light strip fixed by an adhesive sheet to an inner circumferential surface of the lamp tube, a plurality of LED light sources on the LED light strip, two end caps respectively coupled to two opposite ends of the lamp tube, and a power supply circuit on the light strip. The LED light strip with the plurality of LED light sources and power supply circuit are in the lamp tube.

A light source driving method is applied to a light source driving module electrically connected to a light source and a controller. The light source driving module includes a frequency setting module, a driving circuit, and a conversion module. The frequency setting module generates a frequency setting signal according to a switching signal. The driving circuit generates a light source driving signal after receiving the switching signal and a current control signal. The conversion module selectively generates a driving current flowing through the light source in response to the light source driving signal. The driving current increases continuously during a rising duration, and the light source driving signal has a first operating frequency during the rising period. The driving current remains unchanged during a stable duration, and the light source driving signal has a second operating frequency during the stable period.

The present disclosure relates to a switching mode converter. A secondary-side power switch is connected in series in a second output circuit, and an output voltage of a second secondary-side winding is fed back to a first secondary-side winding with a value less than an output voltage of the first secondary-side winding. Thus, a freewheeling current flows completely through the secondary-side winding of the second output circuit when the secondary-side power switch is turned on, and flows through secondary-side windings of other output circuits when the secondary-side power switch is turned off. The freewheeling current flows in a time division manner in each switching cycle for the constant current output circuit and for the constant voltage output circuit. Only one stage of power conversion is needed for multiple constant current/voltage outputs. The switching mode converter increases conversion efficiency, and reduces size because only one group of magnetic components is used.

The invention provides a dimmable lighting apparatus, comprising a lamp body, and a driving circuit and a light emitting circuit in the lamp body. The driving circuit is configured to drive the light emitting circuit to emit light, and the driving circuit includes an input sub-circuit coupled to a mains and a dimming sub-circuit coupled to an external dimmer, the input sub-circuit, and the light emitting circuit. In particular, the input sub-circuit is grounded in a pre-stage manner, and the dimming sub-circuit is grounded in a post-stage manner.

A high power factor control circuit is disclosed, which is used in an AC/DC converter. The converter includes a rectification module, a conversion module and a load. The rectification module receives AC power and rectifies it into a DC current, and the conversion module converts the DC current to drive power as desired by the load and provides it to the load. The conversion module includes a conversion element including an inductive element and a switching element. The control circuit includes a peak limiting signal generator and a switching element control module. The peak limiting signal generator receives a reference signal and produces at least one peak limiting signal from a sample signal. The switching element control module is configured to control switching of the switching element so that, within at least half a line-frequency period, a value of the ripple in the output current flowing through the load is not greater than a limit value.

The present invention discloses a control circuit, a LED driving system, and a LED driving method. The control circuit receives a feedback signal from the power converter and generate a ZCD pulse signal accordingly, indicating one or more moments when the feedback signal decreases to zero, and receives a dimming signal and generate a minimum turn-off time signal accordingly, indicating the moment when a minimum turn-off time is passed. The control circuit generates a first turn-on signal according to the ZCD pulse signal and the minimum turn-off time signal to control a switching device within the power converter to turn on when the feedback signal decreases to zero and the minimum turn-off time is passed.

The present invention discloses a control circuit, a LED driving system, and a LED driving method. The control circuit receives a feedback signal from the power converter and generate a ZCD pulse signal accordingly, indicating one or more moments when the feedback signal decreases to zero, and receives a dimming signal and generate a minimum turn-off time signal accordingly, indicating the moment when a minimum turn-off time is passed. The control circuit generates a first turn-on signal according to the ZCD pulse signal and the minimum turn-off time signal to control a switching device within the power converter to turn on when the feedback signal decreases to zero and the minimum turn-off time is passed.

The invention provides a dimmable lighting apparatus, comprising a lamp body, and a driving circuit and a light emitting circuit in the lamp body. The driving circuit is configured to drive the light emitting circuit to emit light, and the driving circuit includes an input sub-circuit coupled to a mains and a dimming sub-circuit coupled to an external dimmer, the input sub-circuit, and the light emitting circuit. In particular, the input sub-circuit is grounded in a pre-stage manner, and the dimming sub-circuit is grounded in a post-stage manner.

A control circuit includes: a flip-flop having an output configured to be coupled to a control terminal of a transistor and for producing a first signal; a comparator having an output coupled to an input of the flip-flop, and first and second inputs for receiving first and second voltages, respectively; a transconductance amplifier having an input for receiving a sense voltage indicative of a current flowing through the transistor, and an output coupled to the first input of the comparator; a zero crossing detection (ZCD) circuit having an input configured to be coupled to a first current path terminal of the transistor and to an inductor, where the ZCD circuit is configured to detect a demagnetization time of the inductor and produce a third signal based on the detected demagnetization time; and a reference generator configured to generate the second voltage based on the first and third signals.