A circuit for conduction testing of a power supply of a plasma globe lamp includes a rectifying circuit and a switching power supply, the circuit for conduction testing of the power supply of the plasma globe lamp is connected with an alternating current output end of an external power supply, a first end of the rectifying circuit is connected with the alternating current output end of the external power supply, a second end of the rectifying circuit is connected with the switching power supply, and the rectifying circuit is configured to convert an alternating current output by the alternating current output end into a direct current and to output the direct current to the switching power supply, and the rectifying circuit includes at least two diodes and a substrate, and all the at least two diodes are integrated in the substrate.

An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

In a projector, a reflection mirror configured to reflect light emitted from a discharge lamp is disposed on a first end of a discharge lamp main body, a first electrode is disposed on the first end side, each of a first AC period and a second AC period alternately includes a first polarity period in which the first electrode serves as an anode and a second polarity period in which a second electrode serves as an anode, a controller causes a period to transition from the first AC period to the second AC period in a case where an input reception unit receives a stop operation on the projector, and an absolute value of a driving current of the second polarity period in the second AC period is greater than an absolute value of the driving current of the second polarity period in the first AC period.

A discharge lamp driving device includes: a discharge lamp drive unit configured to supply a drive current to a discharge lamp having two electrodes; a voltage detection unit configured to detect an inter-electrode voltage of the discharge lamp; and a control unit configured to control the discharge lamp drive unit, wherein the control unit executes first measurement drive in which a polarity of the drive current is maintained constant at a first polarity, the voltage detection unit measures the inter-electrode voltage multiple times in a first measurement period in which the first measurement drive is executed, and the control unit determines states of the electrodes of the discharge lamp based on a plurality of the inter-electrode voltages measured in the first measurement period.

An LED driver provides constant output power with wide range output current and voltage. A parallel resonant tank configuration is supplemented by resonant gain clamping circuit configured to partially cancel voltage across the resonant capacitor during half-bridge switching operation. Voltage between the resonant components is clamped to one-half a driver input voltage, ensuring inductive switching of the half-bridge. An output transformer has a primary winding coupled across the resonant capacitor, with a center tap defining first and second portions. An output voltage clamping circuit is coupled across the DC input power source and to the center tap, wherein maximum voltage across the primary is clamped based on a relationship between respective numbers of turns in the first and second portions, and maximum voltage across a secondary winding is clamped based on a relationship between the respective numbers of turns in the secondary winding and the first and second portions.

In an aspect of a discharge lamp driving device, a control unit performs first discharge lamp driving in which a first control and a second control are performed, and a second discharge lamp driving in which a third control and a fourth control are performed, a ratio of a DC current in the second control is higher than a ratio of the DC current in the first control, a ratio of the DC current in the fourth control is higher than a ratio of the DC current in the third control and is higher than the ratio of the DC current in the second control, and the control unit performs a transition from the second discharge lamp driving to the first discharge lamp driving in a case where an inter-electrode voltage is lower than a first reverse transition voltage.

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.

Provided are circuits and methods for a digital controller for an electronic ballast for a fluorescent lamp, comprising a feed-forward loop that provides information about a voltage firing angle, and a pulse width modulator that controls a duty ratio of at least one power switch of the electronic ballast according to the information. The digital controller may include a duty ratio controller implemented in the pulse width modulator. The digital controller may include one or more functions such as dimming, maintaining high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end of life protection or lamp failure protection. In one embodiment the ballast is a single stage, single switch ballast.

A lighting apparatus that may comprise a voltage converter operable to supply a current to at least two LED channels coupled between a high voltage rail and a low voltage rail coupled to the voltage converter output is disclosed. The LED channels may be operated to selectively allow a current to flow through them. The lighting apparatus may also have a control module operable to control the total current from the voltage converter and the current through each of the LED channels. The control module may also be operable to set the respective control signals to maintain a constant total current from the voltage converter while permitting aspects of the light output including, the intensity, color, and color temperature to be set and varied. Additionally, the control module may be operable to synchronize the various control signals, obtain a representative sample of the current through the voltage converter, and operate in different modes.

Method for multi-zone temperature control system having temperature control matrix and gate driver; N*M temperature control modules form N-row M-column matrix, power supply line, and power return line; each temperature control module comprising: a temperature control unit adapts to be heated up by electrical power for temperature controlling; semiconductor switch provided with a gate electrode connected with the gate driver, two ends of the gate being connected with the power supply line, and the power return line through the temperature control unit, respectively. In the temperature control matrix, one ends, which are connected with a power return line, of the temperature control units of temperature control modules in a same row or same column are serially connected, and connected with the power supply line; one ends, which are connected with the power supply line at same row or same column are serially connected, and connected with the power supply line.