Abstract: An isolation dimmer circuit structure includes a control circuit module having an input end for receiving a sensing signal and an output end for outputting a control signal. An optocoupler is provided between the control circuit module and a light source power supply circuit. The light source power supply circuit is further connected to a light source. A protection circuit includes first and second resistors and first and second diodes. The first resistor is connected in series between the positive terminal of a DC power supply and the anode of the first diode, forming a node A, the cathode of the first diode is connected to a first terminal of a control input end connected to a traditional dimmer circuit to form an overvoltage protection mechanism.

Abstract: A single-pole (two-wire system) phase-controlled trailing-edge light-modulating circuit comprises a full-bridge rectification circuit, a power supply circuit, a light-modulating control circuit, and a voltage detection circuit. The light-modulating control circuit utilizes a CMOS chip and controls a field effect transistor by detecting specific voltage level to perform a trailing-edge phase control action for modulating light output of resistively and/or capacitively loaded light bulbs, e.g. LED light bulbs. The light-modulating control circuit connects to various lighting loads in series. In addition, the triggering circuit and the power supply circuit of are independent to avoid mutual restrictions to each other that might affect the adjustment of the maximum conduction phase angle.

Abstract: A light emitting system includes a series connection of a light emitting unit and a variable current source, and a voltage conversion device that includes a rectifier circuit and an output circuit. The rectifier circuit rectifies an AC voltage to generate a rectified voltage across a first rectifier output coupled to one end of the series connection of the light emitting unit and the variable current source, and a second rectifier output. The output circuit is coupled between the second rectifier output and another end of the series connection of the light emitting unit and the variable current source, and is configured to generate a direct-current (DC) output voltage.

Abstract: A system and method that adjusts a screen brightness of a display, considering an ambient illumination state, are provided. The method includes receiving a signal, corresponding to an event related to an illumination state alteration, from a sensor, confirming the event, and adjusting, if the event is confirmed, a screen brightness of a display unit in accordance with the event.

Abstract: A fluorescent electronic ballast including: a rectifier circuit, for receiving an AC power supply and converting the AC power supply into a DC power supply; an inverter circuit, coupled to a fluorescent driver circuit, for converting the DC power supply into a high-frequency AC power supply for driving a fluorescent; and a detection protection circuit, coupled to the rectifier circuit and the inverter circuit, for detecting the DC power supply provided by the rectifier circuit, and cutting off the electric connection between a control chip of the inverter circuit and all of power supply when the voltage of the direct current power supply is lower than a predetermined value, wherein the power supply at least includes the direct current power supply provided by the rectifier circuit.

Abstract: A relamping circuit topology to provide a lamping signal in ballast circuits used to power heated filament gas discharge lamps. The relamping circuit includes a low level DC power source, a differential capacitance and a switching device coupled to the differential capacitance. The differential capacitance is configured to produce a relamping signal. The relamping circuit topology also includes an electric current path configured to direct a flow of direct current from the low level DC power supply through a filament of the gas discharge lamp, and to the differential capacitance such that breaking and restoring the electric current path activates the relamping signal.

Abstract: A light source drive circuit is disclosed which uses a low withstanding voltage transistor is discussed. The light source drive circuit can enhance price competitiveness. Also, the light source drive circuit can allow a current flowing through an LED portion to be eliminated when a PWM signal is not applied. Therefore, the light source drive circuit can enhance a contrast ratio.

Abstract: A control unit controls an operation of an electric power conversion unit so that load current that flows through a light source load becomes a constant value, using electric power setting value that is used to determine a size of electric power that is supplied to the light source load and a current detection value that is detected by a current detection resistor (current detection unit), and a load electric power calculation unit obtains load electric power of the light source load using the electric power setting value and a voltage detection value that is detected by a voltage detection unit, and an input electric power estimation unit corrects a circuit loss for the obtained load electric power and estimates input electric power.

Abstract: A switchable luminance LED light bulb, including embodiments that may be used with any common commercial fitting.

Abstract: System and method for igniting one or more high-intensity-discharge lamps. A system includes an ignition controller configured to generate one or more signal pulses for a pulse signal during a first predetermined time period and to cause one or more voltage pulses to be applied to the one or more high-intensity-discharge lamps, the pulse signal changing between a first logic level and a second logic level during the first predetermined time period, each of the one or more signal pulses corresponding to a pulse period, the pulse period being no larger than the first predetermined time period. The ignition controller is further configured to, if the one or more high-intensity-discharge lamps are not successfully ignited after the first predetermined time period, stop generating any signal pulse for the pulse signal for a second predetermined time period, the second predetermined time period being equal to or larger than the pulse period.

Abstract: A lamp (10), such as a rapid thermal processing (“RTP) lamp, is sealed with a press seal (30) that contains a fuse (40). A relatively long press seal region is used that accommodates, in addition to the conventional filament leads to the exterior of the lamp, the fuse as well, the fuse (40) being disposed inside an inert-gas filled void (34) which is formed in the press seal (30), the fuse being thus disposed in an inert environment, such as nitrogen. The void (34) is defined by a bubble (36) formed in the press seal. Alternatively, the void (34) can be defined by an inside region of a glass capillary tube (42) that jackets the fuse and is squeezed into the press seal.

Abstract: A three-stage power adjustable Light Emitting Diode bulb includes a first resistance and a second resistance which is electrically connected to the first resistance in parallel. The first resistance and the second resistance are connected to a rectifier. Multiple Light Emitting Diode units and a limiting resistance are connected between the positive and negative poles of the rectifier. The Light Emitting Diode units each have multiple Light Emitting Diodes. The electric energy consumption of the Light Emitting Diode bulb is reduced and the life of use of the Light Emitting Diode bulb is prolonged. The resistance value of the first and second resistance can be adjusted to have different luminous powers.

Abstract: A portable lighting device, such as a flashlight, with a mechanical power switch and multiple operating modes is provided. The mechanical power switch is disposed in series with the controller for the lighting device and acts as the user interface to the controller to change modes of operation. Because the mechanical power switch is in series with the controller, the portable lighting device does not consume battery power when the mechanical switch is open. A state machine coupled to the controller is polled by the controller each time it is powered up to determine the operational mode of the lighting device.

Abstract: An apparatus and a method for driving a fluorescent lamp are provided. The apparatus submitted by the present invention includes an LC resonator and an automatic frequency tracing circuit. The LC resonator is used for receiving and converting a square signal to generate a sinusoidal driving signal for driving the fluorescent lamp. The automatic frequency tracing circuit is used for making a frequency of the sinusoidal driving signal automatically following a resonant frequency of the LC resonator according to a feedback signal related to the sinusoidal driving signal.

Abstract: A light emitting diode driving integrated circuit with a multi-step current setting function includes a regulator circuit, a variable resistor circuit, and a current generation unit. The regulator circuit provides a supply voltage to a first terminal of at least one series of light emitting diodes to drive the at least one series of light emitting diodes, and regulates a second terminal voltage of the at least one series of light emitting diodes to a target voltage. The variable resistor circuit is used for changing a resistance of the variable resistor circuit in a plurality of steps according to a switching signal. The current generation unit is coupled to the variable resistor circuit for changing current flowing through the at least one series of light emitting diodes in a plurality of steps according to a reference voltage and variation of the resistance of the variable resistor circuit.

Abstract: An LED lamp with an integrated circuit, a rectifier, and a string of series-connected LEDs rectifies an incoming AC signal. The integrated circuit includes power switches that can separately and selectably short out a corresponding one of several groups of LEDs in an LED string across which the rectified AC signal is present. As the voltage across the string increases, the integrated circuit controls the power switches to increase the number of LEDs through which current flows, whereas as the voltage across the string decreases the integrated circuit controls the power switches to decrease the number of LEDs through which current flows. The flow of LED string current is broken to reduce flicker. Alternatively, a valley fill capacitor peaks LED current during the valleys of the incoming AC signal to reduce flicker. LED current is regulated to provide superior efficiency, reliability, power-factor correction, and lamp over-voltage, -current, and -temperature protection.

Abstract: A non-contact and non-disposable electric induction LED lamp includes a power source and a luminous-radiating unit combined together. The power source is formed with a power source module electrically connected with a first electric induction plate, while the luminous-radiating unit is provided with a second electric induction plate corresponding with the first electric induction plate and electrically connected with an LED module. Thus, the electricity of the power source can be transmitted to the luminous-radiating unit via electromagnetic induction produced between the first and the second electric induction plates to enable the LED module to emit light. The LED lamp of this invention can partially be replaced conveniently and has water proof and dustproof effects.

Abstract: In various embodiments, an electric lamp includes a light source having at least two supply lines configured to supply electrical energy to the light source, and an outer bulb surrounding the light source. The outer bulb is filled with inert gas. The lamp further includes a disconnection mechanism arranged within the outer bulb. At least one of the supply lines is interrupted in the event that the disconnection mechanism is tripped. The disconnection mechanism has a switch.

Abstract: Disclosed is an end-of-life detector for gas discharge lamp and the ballast incorporating the same. The end-of-life detector includes a lamp state signal detecting circuit for detecting the lamp state signal of at least one first gas discharge lamp and generating a positive voltage signal and a negative voltage signal accordingly; a comparing circuit for comparing the positive voltage signal with a positive selecting voltage and comparing the negative voltage signal with a negative selecting voltage, and in response thereto generating a positive control signal and a negative control signal; and a positive/negative duty time interval detecting circuit for generating a lamp life state signal which is generated by a difference between a positive duty time interval and a negative duty time interval. The lamp life state signal is varied along with the difference between the positive duty time interval and the negative duty time interval.

Abstract: A semiconductor chip includes an LED driver circuit operably coupled to at least one LED and configured to supply a load current to the at least one LED such that an average load current matches a desired current level defined by a drive signal. A temperature measurement circuit is thermally coupled to the LED driver circuit or the LED(s) or both, and is configured to generate, as drive signal, a temperature dependent signal in such a manner that the drive signal is approximately at a higher constant level for temperatures below a first temperature, is approximately at a lower constant level for temperatures above a second temperature but below a maximum temperature, and continuously drops from the higher constant level to the lower constant level for temperatures rising from the first temperature to the second temperature.

Abstract: A ceiling lamp adopting a non-separating driver circuit includes a conversion module and a control module. The conversion module converts an input voltage into an operating voltage to drive the LEDs and forming a driving current, and the control module monitors the operating voltage and the driving current to adjust the operating cycle of the conversion module, change the output voltage value of the operating voltage, and linearly change the driving current at a constant current state. The conversion module just executes the power conversion for one time to provide the driving power of the LEDs instead of using the conventional driving method that executes a two-stage power conversion by a separating power converter and a negative booster of the conventional ceiling lamp. Therefore, the ceiling lamp adopting a non-separating driver circuit is capable of lowering the circuit cost and improving the operating efficiency.

Abstract: A ceiling lamp adopting a non-separating driver circuit includes a conversion module and a control module. The conversion module converts an input voltage into an operating voltage to drive the LEDs and forming a driving current, and the control module monitors the operating voltage and the driving current to adjust the operating cycle of the conversion module, change the output voltage value of the operating voltage, and linearly change the driving current at a constant current state. The conversion module just executes the power conversion for one time to provide the driving power of the LEDs instead of using the conventional driving method that executes a two-stage power conversion by a separating power converter and a negative booster of the conventional ceiling lamp. Therefore, the ceiling lamp adopting a non-separating driver circuit is capable of lowering the circuit cost and improving the operating efficiency.

Abstract: A single-pole (two-wire system) phase-controlled trailing-edge light-modulating circuit comprises a full-bridge rectification circuit, a power supply circuit, a light-modulating control circuit, and a voltage detection circuit. The light-modulating control circuit utilizes a CMOS chip and controls a field effect transistor by detecting specific voltage level to perform a trailing-edge phase control action for modulating light output of resistively and/or capacitively loaded light bulbs, e.g. LED light bulbs. The light-modulating control circuit connects to various lighting loads in series. In addition, the triggering circuit and the power supply circuit of are independent to avoid mutual restrictions to each other that might affect the adjustment of the maximum conduction phase angle.

Abstract: A power supply or driver circuit configured to provide electrical energy at a drive voltage. The driver circuit converts electrical energy at an input voltage to the electrical energy at the drive voltage. A controller is configured to control the power converter to provide electrical energy at the drive voltage. The controller stops operation at an interruption of electrical energy to the driver circuit. The controller is configured to resume operation subsequent restoration of electrical energy to the driver circuit. The controller is configured to maintain the timing voltage above a first voltage level when the controller is in operation and to determine the duration of an interruption of electrical energy to the driver circuit.

Abstract: An electric lamp (1) has two pairs of external connection pins (5) adapted for connecting the lamp to a voltage source for powering an internal lighting module (3). Each pair of pins is disconnected from the lighting module by an open switch (6) unless a non-zero electric voltage is applied to the pair and causes the switch to close. The lamp is therefore safe to handle even in a condition where one pair of pins is connected and the other is not. The lamp may be fitted in a switch-start fixture, providing an ohmic connection between two pins in different pairs, as well as a rapid-start fixture, with a capacitive connection.

Abstract: A three-stage power adjustable Light Emitting Diode bulb includes a first resistance and a second resistance which is electrically connected to the first resistance in parallel. The first resistance and the second resistance are connected to a rectifier. Multiple Light Emitting Diode units and a limiting resistance are connected between the positive and negative poles of the rectifier. The Light Emitting Diode units each have multiple Light Emitting Diodes. The electric energy consumption of the Light Emitting Diode bulb is reduced and the life of use of the Light Emitting Diode bulb is prolonged. The resistance value of the first and second resistance can be adjusted to have different luminous powers.

Abstract: A LED driver system includes a LED converter converting an input voltage to an output voltage to drive a LED load via a main switch; a sensing circuit generating a feedback signal on the output terminal according to a load current through the LED load; an over-shoot detecting circuit generating an over-shoot signal according to the load current and a second reference signal; a logic circuit generating a switching signal according to a control signal and the over-shoot signal to control the main switch. The control signal is generated according to the feedback signal and a first reference signal, and the second reference signal is larger than the first reference signal.

Abstract: An apparatus for driving a fluorescent lamp is provided. The provided apparatus includes a power switching circuit, an LC resonator and an automatic frequency tracing circuit. The power switching circuit is coupled between an input voltage and a ground potential, and configured for switching and outputting the input voltage and the ground potential in response to two output signals with a phase difference of 180 degrees so as to generate a square signal. The LC resonator is configured for receiving and converting the square signal, so as to generate a sinusoidal driving signal for driving the fluorescent lamp. The automatic frequency tracing circuit is configured for generating and adjusting the two output signals according to a current feedback signal relating to the sinusoidal driving signal, so as to make the frequency of the sinusoidal driving signal automatically follow the resonant frequency of the LC resonator.

Abstract: A bleed circuit is applied to a transformer based on a bleed-on time and a bleed-off time determined by monitoring an output voltage waveform of the transformer.

Abstract: An electronic transformer stabilization circuit includes a detection circuit and a reactive load. The detection circuit may be configured to receive a transformer output or a transformer signal derived from the transformer output. The detection circuit may determine whether the transformer that generated the transformer output is an electronic transformer. The determination may be made based on the presence of absence of high frequency components in the transformer output. Responsive to determining that an electronic transformer generated the transformer output, the stabilization circuit may operate a switch to connect the reactive load across an output of the transformer. The reactive load may include an inductor and may be configured to draw a stabilization current from the transformer. The stabilization current may ensure that the total current drawn from the transformer exceeds an oscillation current required to maintain reliable operation of the electronic transformer.

Abstract: A dimming control and driver for an LED luminaire comprises a shutdown relay connected between an AC source and the driver circuit. The shutdown relay will close above a predetermined control voltage, and will open below the predetermined voltage. The shutdown relay will eliminate parasitic loss by turning the power completely off when the LED luminaire is turned off.

Abstract: The present disclosure relates to a method and apparatus for controlling an illumination device, such as a light bulb, LED light, or the like. In one embodiment, a lighting control adapter is described, comprising a male base for physically attaching the lighting control adapter to a light fixture and for receiving power from the light fixture via a light switch connected to the light fixture, a female socket for receiving a base of an illumination device, a switching circuit for providing switchable power to the illumination device, and a processing circuit coupled to the switching circuit, for detecting one or more power toggles of the power received by the male base, and for controlling illumination of the illumination device based on the detection of one or more detected toggles.

Abstract: An LED backlight driving circuit has a voltage converting unit having an output terminal connected to a positive electrode of an LED to provide a driving voltage required by the LED, a driving unit to control the voltage converting unit to achieve a voltage conversion, and a protection unit connected in series between a negative electrode of the LED and the driving unit. A maximum allowable power of the protection unit is less than a power when the driving voltage of the LED is directly applied to the protection unit. The circuit also includes a control unit for outputting a control signal for stopping working to the driving unit when the protection unit forms an open circuit. Thus, the circuit parts can be protected, and the short-circuit protection function is more safe and reliable.

Abstract: According to one embodiment, a power supply circuit includes: a DC-DC converter which converts a first DC voltage supplied from a power supply flow path into a second DC voltage having a different absolute value, to supply the voltage to a DC load; and an overcurrent protection unit which is electrically connected to an end portion of the DC load on a low potential side, and performs feedback control of the DC-DC converter based on current which flows to the DC load. The DC-DC converter includes a normally-on type switching element. The overcurrent protection unit is electrically connected to the third electrode. When the current which flows to the DC load is greater than a reference value, the overcurrent protection unit changes the state of the switching element from the first state to the second state by decreasing the potential of the third electrode.

Abstract: Embodiments of the present invention generally relate to simplified, high voltage, tungsten halogen lamps for use as source of heat radiation in a rapid thermal processing (RTP) chamber or other lamp heated thermal processing chambers. Embodiments include a lamp design that includes an external fuse while reducing the number of part and expense of prior art lamps. In addition, embodiments of the lamps described herein provide sufficient rigidity to handle compressive forces of inserting the lamps into a heating assembly base, while maintaining a simplified fuse design.

Abstract: A capacitance based reactive power balancing current limited power supply (RPBCLPS) for driving floating DC loads utilizes capacitive reactance to limit current being supplied to a load, rather than inductance. A capacitor transfers charge from an AC current input to a DC load. A fuse electrically protects the capacitor from high frequency current harmonics. A diode clamp electrically protects the capacitor from voltage spikes. A rectifier converts the AC current input into DC current for driving the DC load. The reactive power balancing current limited power supply can be incorporated as a key component into reactive power balancing electrical power distribution systems. Such systems can comprise a grid configuration structured to distribute the AC electrical power from a utility source to a plurality of DC loads. Further, the DC loads can be cooperatively located to provide functional distributed capacitance throughout a substantial portion of the grid.

Abstract: This relates to a current limiter circuit that can be used in a power conversion system having a triac dimmer. In one example, the power conversion system may be used in an off-line LED driver. The current limiter circuit may be coupled to a power converter of the power conversion system and may operate to reduce the current that the power converter receives from an input line in the event of a power line surge. The current limiter circuit may also be coupled to the triac dimmer and may also operate as a damper for a portion of the half line cycle. The current limiter circuit may dampen the ringing in the triac current for a portion of the half line cycle and may cease dampening for the remaining portion of the half line cycle.

Abstract: A driving controller for driving a load is disclosed. The driving circuit includes a driving power supply and the driving controller. The driving power supply provides a first power source to the load. The controller is coupled to a second power source to receive an electric power for operating. The controller controls the amount of the electric power to the load when operating in a first mode and stops the driving power supply from providing the electric power to the load when operating in a second mode. The controller operates exclusively in the first mode before the driving power supply provides the first power source to the load.

Abstract: A voltage supply arrangement for driving an electrical load, particularly a light-emitting diode, comprises a driver circuit (11). The driver circuit (11) features a driver output (12) for making available a driver signal (SB) for controlling a load path (34) that comprises a means (36) for connecting the electrical load (37). The driver circuit (11) furthermore comprises a device (13) for determining an AC signal component of the driver signal (SB), the input side of which is coupled to the driver output (12) and at the output side of which can be tapped a measurement signal (SI) that is dependent on the AC signal component of the driver signal (SB) and according to which a supply voltage (VOUT) of the load path (34) can be adjusted.

Abstract: In examples of the embodiment, a surge-proof interface circuit (100) comprises a rectifier circuit (20) which is configured to produce a rectified rectifier output voltage at the rectifier output terminals (20c, 20d), in accordance with a rectifier input voltage at the rectifier input terminals (20a, 20b), and a Darlington circuit (30) which comprises at least two transistors (Q3, Q4). Said Darlington circuit (30) comprises a current path (35) which can be controlled on the output side in accordance with a control signal (62) and said current path (35) which can be controlled on the output side is coupled between the rectifier output connections (20c, 20d).

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: In one embodiment, an LED driving circuit can include: (i) a sense circuit configured to sense an inductor voltage, and to generate a sense voltage signal; (ii) a protection control circuit configured to activate a first protection control signal in response to a comparison of the sense voltage signal against a first reference voltage to indicate an LED device is in a first load state; (iii) the protection control circuit being configured to activate a second protection control signal in response to a comparison of the sense voltage signal against a second reference voltage to indicate the LED device is in a second load state; and (iv) a PWM control circuit configured to control a power switch according to the first protection control signal or the second protection control signal, based on the load state of the LED device.

Abstract: A semiconductor chip includes an LED driver circuit operably coupled to at least one LED and configured to supply a load current to the at least one LED such that an average load current matches a desired current level defined by a drive signal. A temperature measurement circuit is thermally coupled to the LED driver circuit or the LED(s) or both, and is configured to generate, as drive signal, a temperature dependent signal in such a manner that the drive signal is approximately at a higher constant level for temperatures below a first temperature, is approximately at a lower constant level for temperatures above a second temperature but below a maximum temperature, and continuously drops from the higher constant level to the lower constant level for temperatures rising from the first temperature to the second temperature.

Abstract: An LED drive circuit, which comprises a transformer, an MOS tube, a power regulating resistor, a direct current isolation circuit, a rectifying circuit, and a voltage control circuit; when the voltage of the control terminal of the voltage control circuit is higher than the threshold voltage of the MOS tube, the MOS tube is on, a current from an external power supply flows through the first winding of the transformer, the MOS tube and the power regulating resistor successively; when the voltage of the power regulating resistor is close to the voltage of the reference terminal of the voltage control circuit, the MOS tube is cut off, the second winding of the transformer charges the capacitor of the MOS tube via the direct current isolation circuit, the rectifying circuit is on, and the first winding of the transformer supplies power to the LED load via the rectifying circuit.

Abstract: In some embodiments, a solid state lighting circuit may include one or more of the following features: (a) a plurality of emitters operably connected to a power supply (b) the power supply operably coupled in series with a current limiting device, where one or more of the emitters is bypassed with a switched circuit, and (c) at least one MOSFET switch operably coupled to the voltage divider circuit.

Abstract: This disclosure describes embodiments of a lighting device with circuitry that can manage current and voltage levels across a plurality of fluorescent lamps. In one embodiment, the circuitry has cross-coupled inductors in series with a pair of lamp sockets. This configuration of components causes fluorescent lamps installed in the lamp sockets to generate substantially the same amount of light by drawing approximately equivalent current throughout the entire operable range of a dimmer control. The circuitry also includes a protection circuit with a winding magnetically coupled with the cross-coupled inductors and a control circuit that can cause impedance across the winding to change from a first impedance to a second impedance in response to operating conditions in the lamps. This feature avoids high operating voltages that can occur across the cross-coupled inductors when one of the fluorescent lamps is inoperable and/or removed from the lamp sockets.

Abstract: A portable lighting device, such as a flashlight, with a mechanical power switch and multiple operating modes is provided. The mechanical power switch is disposed in series with the controller for the lighting device and acts as the user interface to the controller to change modes of operation. Because the mechanical power switch is in series with the controller, the portable lighting device does not consume battery power when the mechanical switch is open. A state machine coupled to the controller is polled by the controller each time it is powered up to determine the operational mode of the lighting device. A regulating circuit is used to power a controller and light source. The regulating circuit converts between current regulation and voltage regulation.

Abstract: According to techniques of the application, a method for operating a light fixture in a lighting system may include operating the light fixture in a first mode if a voltage is being supplied to the light fixture. The method may further include, while operating the light fixture in the first mode, detecting whether there has been an interruption in the voltage supplied to the light fixture. The method may further include, if there has been an interruption in the voltage supplied to the light fixture, operating the light fixture in a second mode. The first mode may include an independent timer mode and the second mode may include a synchronized timer mode.

Abstract: A semiconductor apparatus includes an input terminal to which an input voltage is applied; an output terminal at which an output voltage is obtained; a power supply circuit unit configured to generate the output voltage from the input voltage, the output voltage having a value corresponding to a duty cycle of a voltage setting signal that is externally applied to the semiconductor apparatus; and a determination circuit unit determining whether the voltage setting signal has a predetermined signal level for the duration of a first predetermined time or longer. The determination circuit unit activates the power supply circuit unit when the voltage setting signal does not have the predetermined signal level for the duration of the first predetermined time or longer. The power supply circuit unit is deactivated when the voltage setting signal has the predetermined signal level for the duration of the first predetermined time or longer.

Abstract: The present invention provides a light source dimming control circuit, which includes a voltage signal generator for generating a first voltage signal between a predetermined voltage level and a ground level; a reference voltage signal generator for generating a reference voltage signal at an output end according to the first voltage signal and a second voltage signal; a first switch with a first end coupled to an output end of alight source; a first resistor with a first end coupled to a second end of the first switch, and a second end coupled to a ground end; a switch controller coupled to the first switch and the voltage signal generator for controlling on/off states of the first switch according to a sawtooth signal and the first voltage signal; and a current controller for controlling current flowing through the first resistor according to the reference voltage signal.