Abstract: A light emitting diode (LED) dimming circuit includes an amplifier, a switch, a pulse extension circuit, and a reference shaping circuit. The amplifier has an amplifier output, a first amplifier input, and a second amplifier input. The first amplifier input is coupled to a current sense terminal. The switch has a first switch terminal, a second switch terminal, and a switch control input. The first switch terminal is coupled to the amplifier output. The pulse extension circuit has an extended pulse output and a pulse input. The extended pulse output is coupled to the switch control input. The pulse input is coupled to a pulse width modulation (PWM) terminal. The reference shaping circuit has a reference input and reference control input. The reference input is coupled to the second amplifier input. The reference control input is coupled to the PWM terminal.

Abstract: A multi-spark gap having both a high power-follow current extinguishing capacity as well as a relatively low protective level in which a distance x1 between a first electrode and an adjacent second electrode, which together form a first individual spark gap, is larger than respective distances x2 between other adjacent electrode pairs of additional individual spark gaps. The distance x1 is at least 0.5 mm and the distances x2 of the additional individual spark gaps are at most 0.2 mm. Additionally, an ignition aid for igniting the first individual spark gap is provided, which aid has at least a resistive ignition element and a voltage-limiting element, wherein the ignition element is connected to an electric-arc combustion chamber of the first individual spark gap and is electrically connected on the one side to the first electrode and on the other side via the voltage-limiting element to the second contact element.

Abstract: A multimode switch includes a line voltage switch, coupled to a line voltage and a device; a switch controller, responsive to first messages received over a network, that directs the line voltage switch to provide line voltage to, and subsequently remove line voltage from, the device, and that receives first identifying information and a functional group designation for the device in second messages over the network, and that controls the device according to the first identifying information and the functional group designation via transmission of third messages over the network; and a ground leakage power supply, coupled to an AC hot line and to an earth ground, that generates a regulated voltage to power the switch controller without requiring connection to an AC neutral line, while limiting ground leakage current to the earth ground to a prescribed leakage value.

Abstract: A multimode switch includes a line voltage switch, coupled to a line voltage and a device; a switch controller that directs the line voltage switch to provide line voltage to, and subsequently remove line voltage from, the device, and that receives a functional group designation for the device, and that controls the device according to the functional group designation; and a ground leakage power supply, coupled to an AC hot line and to an earth ground, that generates a regulated voltage to power the switch controller without requiring connection to an AC neutral line, while limiting ground leakage current to the earth ground to a prescribed leakage value.

Abstract: A multimode switch includes a line voltage switch, coupled to a line voltage and a device; a switch controller that directs the line voltage switch to provide line voltage to, and subsequently remove line voltage from, the device, and that receives first identifying information for the device, and that controls the device according to the first identifying information; and a ground leakage power supply, coupled to an AC hot line and to an earth ground, that generates a regulated voltage to power the switch controller without requiring connection to an AC neutral line, while limiting ground leakage current to the earth ground to a prescribed leakage value.

Abstract: A multimode switch includes a line voltage switch, coupled to a line voltage and a device; a switch controller that directs the line voltage switch to provide line voltage to, and subsequently remove line voltage from, the device, and that receives first identifying information and a functional group designation for the device, and that controls the device according to the first identifying information and the functional group designation; and a ground leakage power supply, coupled to an AC hot line and to an earth ground, that generates a regulated voltage to power the switch controller without requiring connection to an AC neutral line, while limiting ground leakage current to the earth ground to a prescribed leakage value.

Abstract: The present disclosure relates to a brightness adjustment method and device, and a storage medium. The method can include detecting a brightness of an environment where a mobile terminal is located to acquire a brightness value. When a decrease of the brightness value acquired at a present moment relative to the brightness value acquired at a previous moment reaches a first preset value, a radar wave is transmitted, and an echo of the radar wave is detected. The method determines whether there is an occlusion causing the decrease of the acquired brightness value according to a transmitting parameter of the radar wave and an echo parameter of the echo. When there is no occlusion, display brightness of the mobile terminal is adjusted according to the brightness value acquired at the present moment. When the occlusion is present, the display brightness of the mobile terminal at the present moment is maintained.

Abstract: The present invention relates to a medical coupling unit for electrical signal transmission between the medical coupling unit (1, 1a, 1b) and a medical sensor (2, 2a) coupled to the medical coupling unit. The medical coupling unit comprises a coupling-side connector (10) comprising a plurality of first electrical contacts (11) in or on a first surface (12) and a plurality of second electrical contacts (13) in or on a second surface (14) opposite the first surface, and a connector interface (15) for analyzing electrical signals available at one or more of the plurality of first and second electrical contacts (11, 13) to detect one or more of presence of a medical sensor coupled to the medical coupling unit, the type of medical sensor coupled to the medical coupling unit, and the orientation of a sensor-side connector of a medical sensor coupled to the medical coupling unit. The present invention relates further to a sensor-side connector (20).

Abstract: A zero-crossing detection method, and devices incorporating the method, enable a selectively enabled bias to pull-up a zero-crossing signal, thereby enabling monitoring of the zero-crossing of both half-cycles of the alternating current (AC). This improves synchronization of the device in noisy environments and enables the detection of dimming problems during either half-cycle. Aspects can detect improper dimmer firing events on either polarity of the power cycle and restore normal dimmer operations when needed.

Abstract: A current measurement device comprising: a shunt resistor; a pair of first and second voltage signal lines connected to the shunt resistor; and a current measurement circuit for measuring a current using a signal by the pair of first and second voltage signal lines. The pair of first and second voltage signal lines are connected to an amplifier circuit with which the current measurement circuit is provided to amplify a voltage signal. A third signal line which is a signal line different from the pair of first and second voltage signal lines and drawn from the shunt resistor is connected to a common line of the current measurement circuit.

Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.

Abstract: An OLED driving device includes an overdrive controller (ODC) which executes an overdrive of applying to an OLED an electric current larger than a rated electric current for the OLED for a predetermined period (period for the overdrive) to cause the OLED to emit brighter light for the predetermined period than at the rated electric current for the OLED for light emitting. The controller (ODC) executes a PWM control to the electric current flowing to the OLED for the predetermined period, and sets a PWM signal in the predetermined period so that at least one pulse of a pulse before the OLED starts the light emitting and a pulse at a just time when the OLED starts the light emitting has a width larger than a width of a pulse after the OLED starts the light emitting.

Abstract: A multimode switch includes a wireless transceiver, that transmits/receives messages over a wireless network; a line voltage switch, coupled to a line voltage and associated devices; a switch controller, responsive to first messages received over the wireless network, that directs the line voltage switch to provide line voltage to, and subsequently remove line voltage from, the associated devices, and that receives identifying information and functional group designation for the associated devices in second messages over the wireless network, and that controls the associated devices according to the identifying information and functional group designation via transmission of third messages over the wireless network; and a ground leakage power supply, coupled to an AC hot line and to an earth ground, that generates a regulated voltage to power the wireless transceiver and the switch controller without requiring connection to an AC neutral line, while limiting ground leakage current to the earth ground to a pre

Abstract: Methods, systems, and apparatus to facilitate high side control of a switching power converter are disclosed. An example apparatus includes a latch including a first node coupled to a first source of a first switch and an output coupled to a first gate of the first switch; a first diode coupled to the first node and a second node; a second diode coupled to the second node and ground; a second switch coupled to a voltage source and the second node; and a third switch including a third gate coupled to the second switch, a third source coupled to the second node, and a third drain coupled to the latch.

Abstract: A device, battery and system to reduce battery leakage is provided. The system includes a battery, a battery-powered device, and an interface therebetween comprising cell contacts and a data interface. The battery comprises: a cell; a low-power protection circuit; and a high-power protection circuit configured to receive an indication via the data interface that disables the high-power protection circuit, leaving the low-power protection circuit enabled. The battery-powered device comprises: a high-power subsystem used when the battery-powered device is in an operating state; a switch between the cell contacts and the high-power subsystem; and one or more sensing circuits configured to, in response to determining one or more of a power-off state and a low-battery state: open the switch to the high-power subsystem; and transmit, to the battery, via the data interface, the indication.

Abstract: A first aspect of the present invention will provide a short circuit detector, including: a voltage detection circuit to detect gate voltage which is input from a gate driving circuit to the semiconductor element; and a short circuit detection circuit to detect a short circuit state of the semiconductor element, when gate voltage of the semiconductor element becomes higher than or equal to first reference voltage in a transition period from when a turn-on signal is input to the gate driving circuit until when a mirror period of the semiconductor element starts.

Abstract: A method and apparatus for a printed circuit board having a substrate, an electrical component disposed on the substrate and connected to an input, a wire bond connecting the electrical component to an output, and a gas-generating fuel disposed on the substrate proximate to the wire bond to account for an arc fault.

Abstract: A driving device comprises a first transistor (B13), a second transistor (B14), and a resistance element. The first transistor (B13) has one terminal receiving a pulsed current and a control terminal connected to the one terminal. The second transistor (B14) has one terminal connected to at least one load, the other terminal connected to a reference potential together with the other terminal of the first transistor (B13), and a control terminal connected to the control terminal of the first transistor (B13). The resistance element is connected between the control terminal of the first transistor (B13) and the other terminal of the first transistor (B13).

Abstract: An LED lighting device or LED lamp comprises one or more LED packages, and a switch comprising at least two selectable positions. At least one selectable position corresponds to a set operating mode and one selectable position corresponds to a configurable operating mode. When the switch is in the selectable position corresponding to the set operating mode, responsive to receiving an indication of user input for selecting user-selected operating light qualities, the one or more LED packages continue to be operated in accordance with the predefined operating light qualities corresponding to the set operating mode. When the switch is in the selectable position corresponding to the configurable operating mode, responsive to receiving an indication of user input for selecting user-selected operating light qualities, operation of the one or more LED packages is modified in accordance with the user-selected operating light qualities.

Abstract: A lighting apparatus includes a LED (Light Emitted Diode) module, a wireless module, a rectifier, a first DC-DC (Direct Current to Direct Current) driver, a second DC-DC driver, a capacitor, a pre-charging circuit and a suppressing circuit. The first DC-DC driver converts the first DC power to a second DC power supplying to the LED module according to a PWM (Pulse Width Modulation) signal. The second DC-DC driver is used for converting the first DC power to a third DC power supplying to the wireless module. The capacitor is connected to the LED module in parallel for filtering the second DC power. The pre-charging circuit is used for pre-charging the capacitor in a stand-by mode. The wireless module receives the third DC power in the stand-by mode while the LED module is turned off in the stand-by mode.

Abstract: Provided is a shift register, including a first node control module for controlling a level state of a first node based on an input signal, a first clock signal and a second clock signal. The shift register includes a second node control module for controlling a level state of a second node based on the input signal, the first clock signal, the second clock signal and the level state of the first node. In a phase when the input signal is at high level and the first clock signal is at low level, a third node for controlling a level at the second node is provided with high level, such that in a phase when the input signal is at high level and the second clock signal is at low level, the level at the third node is pulled down so as to provide low level at the second node.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dynamically tuning circuit elements. One aspect includes a zero voltage switching device including a switch, a first comparator, a second comparator and a controller. The switch includes a first terminal, a second terminal, and a control terminal. The first comparator includes a first input terminal electrically connected to the second terminal of the switch and a second input terminal electrically connected to the first terminal of the switch. The second comparator includes a first input terminal electrically connected to a reference voltage and a second input terminal electrically connected to the control terminal of the switch. The controller is configured to: detect a zero voltage condition across the switch, and, in response, cause a control signal to be applied to the control terminal of the switch.

Abstract: A device is disclosed for providing a communication interface for a solid-state luminaire. The disclosed device may be configured, for example, as a dongle to be electrically coupled with power lines between a driver and solid-state light source. The device may draw power from the power lines, while also adjusting and, if desired, monitoring current going to the light source. In some embodiments, the device splits current received from the driver into a first portion that is returned to the driver or consumed within the device and a second portion that is time-modulated and delivered to the light source. In some other embodiments, the device provides a time-varying impedance in series with the driver, reducing current received by the light source in a time-modulated manner. In either case, the device optionally may be configured to cause the light source to output a pulsing light signal encoded with data.

Abstract: A dimmer includes a processing unit structured to generate a dimming control signal, wherein in the on state the dimming control signal has a constant voltage with a low pulse a predetermined time after each zero-crossing in power flowing through the hot conductor and in the off state the dimming control signal has a constant voltage, a load control circuit structured to electrically connect between the hot conductor and the load conductor and to selectively electrically connect the hot conductor to the load conductor based on the dimming control signal, and a snubber control circuit including a snubber structured to electrically couple between the hot conductor and the load conductor, wherein the snubber control circuit is structured to activate the snubber when the dimming control signal has the on state and to deactivate the snubber when the dimming control signal has the off state.

Abstract: Methods, systems, and apparatus to facilitate high side control of a switching power converter are disclosed. An example apparatus includes a latch including a first node coupled to a first source of a first switch and an output coupled to a first gate of the first switch; a first diode coupled to the first node and a second node; a second diode coupled to the second node and ground; a second switch coupled to a voltage source and the second node; and a third switch including a third gate coupled to the second switch, a third source coupled to the second node, and a third drain coupled to the latch.

Abstract: A light emitting diode (LED) tube lamp configured to receive an external driving signal includes an LED module for emitting light, the LED module comprising an LED unit comprising an LED; a rectifying circuit for rectifying the external driving signal to produce a rectified signal, the rectifying circuit having a first output terminal and a second output terminal for outputting the rectified signal; a filtering circuit connected to the LED module, and configured to provide a filtered signal for the LED unit; and a protection circuit for providing protection for the LED tube lamp. The protection circuit includes a voltage divider comprising two elements connected in series between the first and second output terminals of the rectifying circuit, for producing a signal at a connection node between the two elements; and a control circuit coupled to the connection node between the two elements, for receiving, and detecting a state of, the signal at the connection node.

Abstract: Methods, systems, and apparatus to facilitate high side control of a switching power converter are disclosed. An example apparatus includes a latch including a first node coupled to a first source of a first switch and an output coupled to a first gate of the first switch; a first diode coupled to the first node and a second node; a second diode coupled to the second node and ground; a second switch coupled to a voltage source and the second node; and a third switch including a third gate coupled to the second switch, a third source coupled to the second node, and a third drain coupled to the latch.

Abstract: An output driver circuit provides an overcurrent protection function by a simple circuit configuration. The output driver circuit has a constant-current circuit, a constant-current mirror MOS transistor, and a selector circuit. The constant-current mirror MOS transistor and the output MOS transistor constitute a current mirror circuit. The gate of the output MOS transistor is controlled by a voltage based on a constant current generated by the constant-current mirror MOS transistor, thereby limiting the current flowing between the source and the drain of the output MOS transistor.

Abstract: System controller and method for a lighting system according to certain embodiments. For example, the system controller includes a first controller terminal configured to receive a first signal, and a second controller terminal coupled to a first transistor terminal of a transistor. The transistor further includes a second transistor terminal and a third transistor terminal. The second transistor terminal is coupled to a first winding terminal of a winding, and the winding further includes a second winding terminal coupled to a capacitor. Additionally, the system controller includes a third controller terminal coupled to the third transistor terminal of the transistor, and a fourth controller terminal coupled to a resistor and configured to receive a second signal. The second signal represents a magnitude of a current flowing through at least the winding, the third controller terminal, the fourth controller terminal, and the resistor.

Abstract: System controller and method for a lighting system according to certain embodiments. For example, the system controller includes a first controller terminal configured to receive a first signal, and a second controller terminal coupled to a first transistor terminal of a transistor. The transistor further includes a second transistor terminal and a third transistor terminal. The second transistor terminal is coupled to a first winding terminal of a winding, and the winding further includes a second winding terminal coupled to a capacitor. Additionally, the system controller includes a third controller terminal coupled to the third transistor terminal of the transistor, and a fourth controller terminal coupled to a resistor and configured to receive a second signal. The second signal represents a magnitude of a current flowing through at least the winding, the third controller terminal, the fourth controller terminal, and the resistor.

Abstract: Electronic ballast for controlling at least one load, for example a lamp such as an LED, a fluorescent lamp, a gas discharge lamp or the like, comprising at least one resonant converter for generating a start and/or operating voltage from a rectified mains voltage of a mains voltage supply and comprising a mains rectifier for rectifying the mains voltage, where the electronic ballast has an electronic switching device that switches off the mains voltage supply in the event of emergency lighting, an emergency voltage can be fed into the electronic ballast, and different voltages can be determined and/or operating frequencies of the electronic ballast can be adjusted by way of an intermediate voltage circuit and/or an operating frequency circuit.

Abstract: A dimmable LED module configured for electrical connection with an AC mains power supply via a switch (9), the dimmable lighting module including a plurality of activatable LED light sources configured for emitting a corresponding lighting characteristic when activated, and, a control unit (4) configured for selectably activating at least one of the plurality of LED light sources in response to a control signal generated by a predetermined switching operation of the switch (9) that is received by the control unit (4) such that a plurality of lighting modes are able to be selectably output from the dimmable LED module corresponding to the at least one of the plurality of LED light sources that are selectably activated by the control unit (4), the plurality of lighting modes being indicative of a resulting lighting characteristic emitted by the at least one of the plurality of selectably activated LED light sources corresponding to the lighting modes, wherein the plurality of lighting modes include at least a f

Abstract: An LED lighting device or LED lamp comprises one or more LED packages, and a switch comprising at least two selectable positions. At least one selectable position corresponds to a set operating mode and one selectable position corresponds to a configurable operating mode. When the switch is in the selectable position corresponding to the set operating mode, responsive to receiving an indication of user input for selecting user-selected operating light qualities, the one or more LED packages continue to be operated in accordance with the predefined operating light qualities corresponding to the set operating mode. When the switch is in the selectable position corresponding to the configurable operating mode, responsive to receiving an indication of user input for selecting user-selected operating light qualities, operation of the one or more LED packages is modified in accordance with the user-selected operating light qualities.

Abstract: A symmetry control circuit for a trailing edge phase control dimmer circuit for controlling alternating current (AC) power to a load, the symmetry control circuit including: a bias signal generator circuit configured to monitor non-conduction periods of each half cycle of said AC power for an elapsed duration of the non-conduction periods, and generate a bias signal voltage based on the elapsed duration, whereby an amplitude of the bias signal voltage is proportional to the elapsed duration of the non-conduction periods; and a bias signal converter circuit configured to convert the bias signal voltage to a bias signal current, wherein the bias signal current is added to a reference current of a conduction period timing circuit configured to determine said conduction periods, and wherein the conduction period timing circuit is configured to alter one of the conduction periods immediately following one of the non-conduction periods based on the bias signal current when added to the reference current to compensa

Abstract: A controller for use in a power converter includes a sense circuit coupled to generate a feedback signal representative of an output voltage of the power converter. A feedback reference circuit coupled to generate a drive signal in response to the feedback signal. An output power control circuit coupled to receive a current sense signal representative of an output current of the power converter and a power signal representative of a desired value of an output power of the power converter via an interface. The controller modifies the output voltage to regulate to the output power to the desired value.

Abstract: A dimmer circuit configured for detecting an overvoltage event comprising a controller, a plurality of dimming transistors, a current sensor, and an overvoltage protection device coupled across at least one of the plurality of dimming transistors. The dimmer circuit generates a transistor drive signal to drive the plurality of dimming transistors at a reverse phase dimming mode and provides a dimmed hot output signal to a load. After driving at least one of the dimming transistors to turn off, the dimmer circuit receives from the current sensor a detected current level (I) of the dimmed hot output signal at a turn off time threshold (Tth) and compares the detected current level (I) to a current threshold (Ith). The dimmer circuit detects an overvoltage event when the detected current level (I) is above the current threshold (Ith) because this indicates that the overvoltage protection has tripped.

Abstract: A light emitting diode (LED) driver provided with a time delay circuit. The time delay circuit includes a power detector which detects whether alternating current (AC) power is applied and outputs a power detection signal when the AC power is applied, a time delayer which receives LED driving power, delays outputting the input LED driving power by a predefined delay time when the power detection signal is output from the power detector, and outputs a delay time completion signal, and a power outputter which outputs the LED driving power when the delay time completion signal is input from the time delayer.

Abstract: A ballast circuit for a lighting system using an induction fluorescent lamp utilizes an AC-DC rectification circuit, a DC-DC boost power conversion circuit, a DC-AC half bridge inverter circuit, and a resonating circuit to ignite the lamp and maintain substantially constant power output of the lamp, while the DC-AC half bridge inverter circuit is further comprised of a gate isolation transformer connected in a half bridge inverter schematic which uses a ballast integrated circuit (IC) to drive a high side MOSFET and a low side MOSFET and the gate isolation transformer electrically isolates a gate signal to the high side MOSFET.

Abstract: Disclosed are method and device for controlling illumination, belonging to the field of display control technology. The method includes acquiring an environmental brightness, determining a illumination parameter of a visual indicator disposed at a mobile device based on the environmental brightness, and controlling the visual indicator to illuminate based on the illumination parameter.

Abstract: Methods of regulating an output voltage of a switched mode power supply having a variable input voltage and a power switch include adjusting a reference voltage to adjust a duty cycle of a control signal for the power switch. The reference voltage may be adjusted as a function of the duty cycle, in response to the duty cycle of the control signal being outside a defined range and/or in the response to a temperature within the switched mode power supply being above a threshold temperature. Other methods include selecting a reference voltage from a plurality of reference voltages based on a determined input voltage and generating a control signal for the power switch as a function of the selected reference voltage to adjust the duty cycle of the control signal. Switched mode power supplies and control circuits for implementing the methods are also disclosed.

Abstract: An LED tube lamp includes a lamp tube receiving an external driving signal; a rectifying circuit rectifying the external driving signal to produce a rectified signal; a filtering circuit filtering the rectified signal to produce a filtered signal; an LED lighting module comprising a driving circuit and an LED module, the driving circuit, in a first driving mode, receiving the filtered signal to produce a first driving signal for driving the LED module to emit light; and a mode switching circuit receiving the filtered signal as a second driving signal in a second driving mode for driving the LED module to emit light. Wherein, the first driving mode and the second driving mode are determined based on the external driving signal.

Abstract: A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

Abstract: An LED driver circuit and a method prevent LED turn-off flash when input power is lost to the driver circuit. The driver circuit includes a DC-DC converter that provides an LED drive voltage to an LED load. A voltage drop sensing circuit detects the loss of input power and discharges a filter capacitor that provides operating power to a controller in a DC-DC converter. The controller turns off to halt the operation of the DC-DC converter before the voltage provided to the LED load decreases to a turn-off threshold of the LED load. The DC-DC converter cannot recharge a load capacitor across the LED load. Thus, once the LEDs in the LED load turn off, the LEDs remain off until the input power is restored.

Abstract: The LED tube lamp includes a lamp tube configured to receive an external driving signal; a rectifying circuit configured to rectify the external driving signal to produce a rectified signal; a filtering circuit coupled to the rectifying circuit, and configured to filter the rectified signal to produce a filtered signal, wherein the filtering circuit has a first filtering output terminal and a second filtering output terminal; an LED lighting module coupled to the filtering circuit, wherein the LED lighting module includes a driving circuit having a first driving output terminal and a second driving output terminal and configured to receive the filtered signal to produce a driving signal, and an LED module configured to receive the driving signal and emit light; and a mode switching circuit coupled to at least one of the first and the second filtering output terminal and at least one of the first and the second driving output terminal, and configured to determine to perform one of a first driving mode and a se

Abstract: A switching power supply device includes a switching circuit and a control circuit. The switching circuit includes multiple switching elements, an inductor, and a capacitor. The control circuit compares an input voltage of the switching circuit with a predetermined threshold voltage set for an operation switch, and controls the switching circuit to perform the operation switch between at least two power control operations based on a comparison result. The at least two power control operations includes at least two of a buck operation, a buck-boost operation, or a boost operation. The control circuit further performs an inrush current restriction operation in response to the operation switch in order to restrict a flowing of an inrush current to one of the switching elements, which turns on and outputs the input voltage through the inductor in response to the operation switch.

Abstract: An illumination lamp includes: an input portion connectable to any one of power supply portions for two or more starting methods including a rapid-start method; a voltage detection circuit configured to detect a voltage applied from a power supply portion; and a control portion including at least one first voltage supply portion configured to supply a voltage suitably for the rapid-start method to a semiconductor light-emitting device, and at least one second voltage supply portion configured to supply a voltage suitably for the other fluorescent-lamp starting method to the semiconductor light-emitting device. The control portion causes, if the voltage is detected by the voltage detection circuit, the first voltage supply portion to supply a voltage to the semiconductor light-emitting device, but causing, if the voltage is not detected by the voltage detection circuit, the second voltage supply portion to supply a voltage to the semiconductor light-emitting device.

Abstract: A light-emitting diode (LED)-based solid-state universal lamp using a ballast compatible and AC-mains operable (BA) LED driving circuit with a power factor correction (PFC) and control device operates normally for a regulated power and current from either ballast or AC mains. The BA LED driving circuit is configured to operate in a wide range of input voltages and frequencies, especially for various high voltages and high frequencies associated with various ballasts. With a cycle-by-cycle current control and power switching at a constant on-time and varied off-time, an over-rated surge current is limited, preventing occasional fire hazards occurred in the ballast.

Abstract: A lighting device includes at least first and second lighting circuits configured to receive electric power from a single common DC power supply. First lighting circuit includes a first output capacitor connected between output ends thereof, and a first pre-charge circuit configured to keep a voltage across first output capacitor at a first voltage for first lighting circuit, while a first light source is in OFF state. Second lighting circuit includes a second output capacitor connected between output ends thereof; and a second pre-charge circuit configured to keep a voltage across second output capacitor at a second voltage for second lighting circuit, while a second light source is in OFF state. First and second voltages are set such that a difference between a forward voltage of first light source and the first voltage agrees with a difference between a forward voltage of second light source and the second voltage.

Abstract: The invention discloses an LED backlight drive circuit, an LCD device and a driving method. The LED backlight drive circuit includes a power source; an output capacitor and an LED lightbar which is connected in series with a first controllable switch are in parallel connection, and then are arranged between the output terminal and the ground terminal of the power source. The LED backlight drive circuit further includes a first comparator; a cathode of the first comparator is connected to a first reference voltage, an anode of the first comparator is coupled with the output terminal of the power source, and the output terminal of the first comparator is coupled with a control end of the first controllable switch; when the anode voltage of the first comparator exceeds the cathode voltage, the output terminal of the first comparator drives the first controllable switch to be conducted. In the invention, the LED lightbar only can be conducted at the predetermined voltage.

Abstract: A device provides a bypass path for leakage current of a neutral-less controller in a lighting control system for selectively supplying line voltage to a load. The device includes a dummy load, a voltage sensor, a bypass switch, a switch controller and a delay timer. The voltage sensor senses line voltage at an output of the neutral-less controller. The bypass switch selectively connects the dummy load in parallel with the lighting load. The switch controller activates the bypass switch to connect the dummy load in parallel with the lighting load when the line voltage is low, providing a bypass path for the leakage current, and deactivates the bypass switch after a delay period to disconnect the dummy load from being in parallel with the lighting load when the line voltage is high. The delay timer implements the delay period in response to the line voltage transitioning from low to high.