Abstract: An LED lamp arrangement is disclosed to replace a fluorescent lamp in a luminaire with a ballast. The LED lamp arrangement has a rectifier, LEDs, a LED driver, an impedance balance circuit, a line-voltage controller. The rectifier has two inputs connected to the ballast to provide a rectified power line and a ground power line. The LEDs and a LED driver are connected in series between the rectified power line and the ground power line, and the LED driver regulates a LED driving current through the LEDs. The impedance balance circuit is coupled between the inputs. The line-voltage controller controls the impedance balance circuit in response to a line voltage at the rectified power line, so as to tune an impedance between the inputs and make the line voltage approach to a predetermined target voltage.

Abstract: An integrated circuit is suitable for use in an AC LED lamp and is configured to control a power bank coupled between a rectified input voltage and a ground voltage. The AC LED lamp has LED groups arranged in series between the rectified input voltage and the ground voltage. The power bank has a capacitor storing electric energy and a discharge switch coupled between the capacitor and the rectified input voltage. The integrated circuit has a path controller and a bank controller. The path controller controls conduction paths, each coupling a corresponding LED group to the group voltage. The bank controller turns on the discharge switch in response to a first path signal corresponding to a first conduction path, and turns off the discharge switch in response to a second path signal corresponding to a second conduction path. The first and second path signals are different from each other.

Abstract: A LED lighting system efficiently provides an operating voltage powering integrated circuits. A LED string has LEDs segregated into LED groups connected in series. A LED controller has channel nodes connected to the cathodes of the LED groups respectively, and an output node connected to a capacitor providing the operating voltage. The LED controller drains a channel current from a selected channel node among the channel node. The LED controller regulates the channel current to a channel target value corresponding to the selected channel node, and provides a portion of the channel current as a charging current to power and regulate the operating voltage.

Abstract: A LED lighting system performs no flicking. A rectifier receives an AC input voltage to generate a rectified input voltage at an input power line and a ground voltage at a ground line. A LED string comprises LEDs connected in series to have a main anode and a main cathode. The main anode is coupled to the input power line. A power bank is connected to the input power line and the main cathode. The circuit conducts a first driving current from the main cathode to the ground line, and a second driving current from the power bank to the ground line. The second driving current increases electric energy stored in the power bank. Both the first and second driving currents flow through the LED string. The power bank releases the electric energy to make at least one of the LEDs illuminate when the AC input voltage is about 0V.

Abstract: A LED lamp has LED groups, a path controller, a power bank, and a bank controller. The LED groups are arranged in series between a rectified input voltage and a ground voltage. The path controller controls path switches, each path switch for coupling a corresponding LED group to the ground voltage. The power bank is coupled between the rectified input voltage and the ground voltage, having a capacitor and a discharge switch. The capacitor is configured to be charged when the rectified input voltage exceeds a capacitor voltage of the capacitor. The discharge switch is connected between the capacitor and the rectified input voltage. The bank controller determines a connection period and controls the discharge switch in response to a signal turning ON one of path switches, in order to make the capacitor capable of being discharged to the rectified input voltage during the connection period.

Abstract: LED controllers, LED lighting systems and control methods capable of providing an average luminance intensity independent from the variation of an AC voltage. A string of LEDs are divided into LED groups electrically connected in series between a power source and a ground. A LED controller has path switches, each for coupling a corresponding LED group to the ground. A management center controls the path switches, for making an input current from the power source to the string substantially approach a target value. A line waveform sensor coupled to the power source holds a representative signal during a cycle time of the power source. The representative signal is in response to an attribute of the power source, and substantially determines the target value.

Abstract: LED controllers, LED lighting systems and control methods capable of providing an average luminance intensity independent from the variation of an AC voltage. LEDs are divided into LED groups electrically connected in series between a power source and a ground. A disclosed LED controller has path switches, a management center and a line waveform sensor. Each path switch is for coupling a corresponding LED group to the ground. The management center controls the path switches. When turning off an upstream path switch, the management center controls a downstream path switch for a downstream LED group to make the driving current passing the upstream LED group substantially approach a target value. The line waveform sensor is coupled to the power source, sensing the waveform of the input voltage of the power source. The line waveform sensor is configured to decrease the target value when the input voltage increases.

Abstract: Disclosed are methods and lighting system with LEDs. An exemplified system comprises series-coupled light-emitting diodes, an integrated circuit, and an energy storage apparatus. The series-coupled light-emitting diodes are divided into several LED groups coupled in series. The integrated circuit comprises nodes respectively coupled to the LED groups, for providing a driving current to selectively flow through at least one of the LED groups. The energy storage apparatus has two ends coupled to a predetermined LED in a predetermined LED group. When the driving current flows through the predetermined LED group the energy storage apparatus energizes; and when the driving current does not flow through the predetermined LED group the energy storage apparatus de-energizes to illuminate the predetermined LED.

Abstract: Disclosed are methods and lighting system with LEDs. An exemplified system comprises series-coupled light-emitting diodes, an integrated circuit, and an energy storage apparatus. The series-coupled light-emitting diodes are divided into several LED groups coupled in series. The integrated circuit comprises nodes respectively coupled to the LED groups, for providing a driving current to selectively flow through at least one of the LED groups. The energy storage apparatus has two ends coupled to a predetermined LED in a predetermined LED group. When the driving current flows through the predetermined LED group the energy storage apparatus energizes; and when the driving current does not flow through the predetermined LED group the energy storage apparatus de-energizes to illuminate the predetermined LED.

Abstract: While an electronic product including passive elements is connected to an AC input voltage source, corresponding decreased currents are calculated according to a constant input/output work and a voltage curve of the input voltage source. Therefore, while the electronic product is activated under voltage sources having different scales or being unstable, the calculated decreased currents are applied so as to stabilize the input work or the output work.

Abstract: A driving circuit includes a switch, a detecting unit, a current supply unit, and an energy storage unit. The current supply unit is used for providing a driving current for at least one series of light emitting diodes. The detecting unit is used for comparing a voltage of a first terminal of the detecting unit with a reference voltage to generate a switch control signal. When the switch is turned on according the switch control signal, a first voltage drives the series of light emitting diodes through the switch and the energy storage unit is charged according a charge current. When the switch is turned off according the switch control signal, the energy storage unit drives the series of light emitting diodes according to a discharge current.

Abstract: A driving circuit includes a switch, a detecting unit, and a current supply unit. A first terminal of the switch is used for coupling to a first terminal of a first LED group of a plurality of LED groups and receiving a first voltage, and a third terminal of the switch is used for coupling to a first terminal of a last LED group of the plurality of LED groups. The detecting unit is used for outputting a switch control signal to a second terminal of the switch for controlling turning-on and turning-off of the switch. The current supply unit has a plurality of input current terminals, and a ground terminal coupled to ground, where each input current terminal of the plurality of input current terminals is used for coupling to a second terminal of a corresponding LED group of the plurality of LED groups.

Abstract: An LED driving circuit includes a current selecting circuit. The current selecting circuit controls the current transmission path in the plurality of LEDs according to respective threshold voltages of corresponding LEDs and a plurality of current limits.

Abstract: A voltage converter transmits energy in multiple stages using a charge pump so as to decrease the voltage rating of the secondary side of the transformer and reduce the size of the transformer. Meanwhile, the voltage converter stores and recycles the leakage inductance energy by using a snubber circuit so as to increase the efficiency.

Abstract: A flyback converter system prevents a primary side switch and a secondary side switch from being turned on simultaneously through a controller. The controller includes a turning on switch module, a turning off switch module, and an enabling switch module. The turning on switch module is for turning on the secondary side switch. The turning off switch module switches off the secondary side switch according to the impedance of a load and the switch cycle of the secondary side switch. The enabling switch module enables the secondary side switch according to the impedance of the load.

Abstract: A control circuit of a driving circuit for controlling a light emitting diode (LED) light source having a plurality of areas is provided. The control circuit includes the error amplifiers receiving a feed back current signal and a external reference voltage, and generating an error signal; a buffer register receiving a serial digital signal and generating the parallel digital signals; a work register receiving the parallel digital signals and a trigger signal, and outputting the parallel digital signals when the trigger signal is at a relatively high level; and a switch module having the power switches, each of which receives the error signal and the parallel digital signal for generating a driving signal to control a driving current of a specific area of the light source, in order to control the brightness in each area of the LED light source.

Abstract: The present invention discloses a current generating apparatus for generating an output current. The current generating apparatus includes: a first current mirror; a first bias current generator for providing a first bias current, and the first bias current generator includes: a first current source for providing the first current; and a capacitive device for conducting a reference current; a second current mirror for generating a second mirror current; a second bias current generator for generating a second current; a third current source for providing a third current, wherein the second mirror current is equal to the third current; a feedback circuit; and a fourth current source for providing a fourth current, wherein the output current is outputted at an output node of the first current mirror.

Abstract: A bandgap reference voltage circuit is provided, in which an additional resistor as well as a transistor is utilized to prevent the source-drain voltage of a metal oxide semiconductor field effect transistor electrically connected to an output terminal of the bandgap reference voltage circuit from falling into the triode region. Through the provided bandgap reference voltage circuit, the temperature compensation effect is able to be normally executed, so as to supply a stable bandgap reference voltage.

Abstract: The invention relates to a single-chip gyro device, which includes a substrate, a plurality of metal layers and a plurality of dielectric layers, and a plurality of metal side walls. Each of the dielectric layers is located between two adjacent layers selected from a layer group consisting of the metal layers and the substrate. The metal side walls are located on edges of the plurality of dielectric layers so as to prevent the dielectric layers from being undercut and form a mechanical structure together with the metal layers and the dielectric layers to connect the circuit formed on the substrate.

Abstract: A bandgap reference voltage circuit is provided, in which an additional resistor as well as a transistor is utilized to prevent the source-drain voltage of a metal oxide semiconductor field effect transistor electrically connected to an output terminal of the bandgap reference voltage circuit from falling into the triode region. Through the provided bandgap reference voltage circuit, the temperature compensation effect is able to be normally executed, so as to supply a stable bandgap reference voltage.