A method for driving a unidirectional current through an electrical load, such as one or more LED modules, by applying thereto a PWM-modulated signal that swings between a high value and a low value envisages choosing said high value and said low value as nonzero values having a same sign.

A method for driving a unidirectional current through an electrical load, such as one or more LED modules, by applying thereto a PWM-modulated signal that swings between a high value and a low value envisages choosing said high value and said low value as nonzero values having a same sign.

A light-emitting diode (LED) tube lamp and an electric leakage protection circuit are provided. The LED tube lamp. The LED tube lamp includes a leakage detecting module and a driving module comprising a Type A+B driving circuit. The leakage detecting module is connected with a power supply. The driving module is electrically connected with the leakage detecting module. The leakage detecting module detects a signal related to the output current of the power supply, and when the signal related to the output current of the power supply exceeds a reference signal, the leakage detecting module limits the current on a power loop connected to the power supply by periodically turning off a switch electrically connected to the power loop in series.

A light emitting device controls its mixed CCT by the configuration of at least one light emitter, at least one diode and at least two power distribution components. The present disclosure is mainly based on the hardware design of diode and jumper, which effectively replaces the resistors and manual switches of the conventional light emitting device with diodes, wherein the resistors and the manual switches of the conventional light emitting device cause voltage instability and other problems. The present disclosure can achieve the demand for miniaturization of the light emitting device by plugging the jumper into pins, and further can achieve the main advantages of stabilizing the voltage of the overall light emitting device, thereby stabilizing the luminous performance of the overall light emitting device, and emitting the mixed light with the required CCT. The present disclosure also illustrates a lamp assembly using the aforementioned light emitting device.

A light emitting device controls its mixed CCT by the configuration of at least one light emitter, at least one diode and at least two power distribution components. The present disclosure is mainly based on the hardware design of diode and jumper, which effectively replaces the resistors and manual switches of the conventional light emitting device with diodes, wherein the resistors and the manual switches of the conventional light emitting device cause voltage instability and other problems. The present disclosure can achieve the demand for miniaturization of the light emitting device by plugging the jumper into pins, and further can achieve the main advantages of stabilizing the voltage of the overall light emitting device, thereby stabilizing the luminous performance of the overall light emitting device, and emitting the mixed light with the required CCT. The present disclosure also illustrates a lamp assembly using the aforementioned light emitting device.

Disclosed is an LED driving apparatus. The LED driving apparatus comprises an LED driving circuit, a power supply unit for supplying a driving voltage to the LED driving circuit, a voltage ripple controller located between the LED driving circuit and the power supply unit, and a switching unit for controlling a voltage supplied to the LED driving circuit by turning on or off the voltage ripple controller according to a duty ratio of a pulse width modulation (PWM) dimming signal.

Disclosed is an LED driving apparatus. The LED driving apparatus comprises an LED driving circuit, a power supply unit for supplying a driving voltage to the LED driving circuit, a voltage ripple controller located between the LED driving circuit and the power supply unit, and a switching unit for controlling a voltage supplied to the LED driving circuit by turning on or off the voltage ripple controller according to a duty ratio of a pulse width modulation (PWM) dimming signal.

A lighting circuit turns on multiple semiconductor light sources. Multiple current sources are each coupled in series with a corresponding one from among the semiconductor light sources. A switching converter supplies a driving voltage V.sub.OUT across each of multiple series connection circuits formed of the multiple semiconductor light sources and the multiple current sources. A converter controller controls a switching transistor of the switching converter based on a relation between a voltage across one from among the multiple current sources and a reference voltage having a positive correlation with the temperature T.sub.j.

A lighting circuit turns on multiple semiconductor light sources. Multiple current sources are each coupled in series with a corresponding one from among the semiconductor light sources. A switching converter supplies a driving voltage V.sub.OUT across each of multiple series connection circuits formed of the multiple semiconductor light sources and the multiple current sources. A converter controller controls a switching transistor of the switching converter based on a relation between a voltage across one from among the multiple current sources and a reference voltage having a positive correlation with the temperature T.sub.j.

The present disclosure relates to current control circuitry for controlling a current through a load. The current control circuitry comprises amplifier circuitry, reference voltage generator circuitry configured to supply a fixed reference voltage to a first input of the amplifier circuitry and an output stage comprising: a control terminal coupled to an output of the amplifier circuitry; a current input terminal configured to be coupled to the load; and a current output terminal. The current control circuitry further comprises a variable resistance coupled to the current output terminal of the output stage, and a feedback path between the current output terminal of the output stage and a second terminal of the amplifier circuitry for providing a feedback voltage to a second input of the amplifier circuitry.