Abstract: A multi-charge ignition system includes a spark plug control unit adapted to control at least two coil stages so as to successively energise and de-energise the coil stages to provide a current to a spark plug. The two stages include a first transformer including a first primary winding inductively coupled to a first secondary winding; a second transformer including a second primary winding inductively coupled to a second secondary winding. An auxiliary primary winding is connected from the common high side of the primary winding in series to an auxiliary secondary winding, the other end of said auxiliary secondary winding is electrically connected to ground/low side, and includes a switch which selectively allows current to pass through the auxiliary windings.

Abstract: An insulated power supply device includes: an electric power conversion unit, a rectifier, a filter, a detection unit, a control circuit, and a signal transmission unit. The control circuit generates and outputs a control signal for a switching element that controls a current to be flown through a primary side of the electric power conversion unit. The signal transmission unit transmits, to the control circuit, a detection signal by the detection unit for detecting an output current or an output voltage. An output control pulse signal having control information in a duty ratio can be supplied as an outputted control signal individually to both of the control circuit and a secondary side of the electric power conversion unit. The output current or the output voltage can be thereby controlled.

Abstract: In one embodiment, an AC/DC power converter can include: a rectifier bridge and a filter capacitor for converting an external AC voltage to a half-sinusoid DC input voltage; a first storage component, where during each switching cycle in a first operation mode, a first path receives the half-sinusoid DC input voltage to store energy in the first storage component, and a first current through the first storage component increases; a second storage component, where a second path receives a second DC voltage to store energy in the second storage component, and a second current through the second storage component increases; and a third storage component, where in a second operation mode, the first current decreases to release energy from the first to the third storage component, where the second DC voltage includes a voltage across the third storage component through a third path.

Abstract: In various embodiments, a two-switch flyback power supply may include a transformer having a primary winding and a secondary winding to feed a load; a pair of electronic switches alternatively switchable on and off to connect the primary winding of said transformer to an input line to feed said primary winding of said transformer, wherein at least one of said electronic switches is an electronic switch having a control electrode floating with respect to ground; a capacitive voltage divider arranged between said input line and the ground of the device, with the dividing point of said capacitive voltage divider connected to an intermediate point of said primary winding of said transformer; and an auxiliary secondary winding in said transformer, said auxiliary secondary winding feeding the control electrode of said at least one of said electronic switches.

Abstract: System and method for adjusting brightness of one or more cold-cathode fluorescent lamps. The system includes a voltage selector configured to receive a dimming voltage and a first threshold voltage and generate an output voltage. The output voltage is selected from a group consisting of the dimming voltage and the first threshold voltage. Additionally, the system includes an oscillator coupled to a first capacitor and configured to generate a ramp signal with the first capacitor, and a signal generator configured to receive the ramp signal and the output voltage and generate a first signal. The first signal corresponds to a lamp brightness level. Moreover, the system includes a brightness detector configured to receive the first signal and output a second signal. The second signal indicates whether the lamp brightness level is higher than a threshold brightness level.

Abstract: Embodiments of the present disclosure include an LED ballast circuit for dimming one or more LEDs using a phase controlled dimmer switch. The LED ballast circuit has a power conditioning unit which includes a substantially fixed duty cycle clock for outputting a clock cycle and a transformer configured to store energy and discharge a substantial portion of the stored energy once per clock cycle in order to power one or more LEDs.

Abstract: An emergency lighting device (1) for operating a light source, in particular an LED, incorporates an energy storage unit (4), a charging circuit (3) to be supplied with mains supply voltage (Uin) for charging the energy storage unit (4) during a charging operation, wherein the charging circuit (3) has potential isolation, and a driver circuit (5) supplied by the energy storage unit (4) during operation of the emergency light, for operating the light source. A control unit (2) is further provided that is designed to monitor the state of the mains supply voltage (Uin) during the charging operation, and to activate emergency operation upon detecting an emergency state, wherein the control unit (2) determines the state of the mains supply voltage (Uin) from operating parameters of the emergency lighting device (1) measured on the output side of the charging circuit (3).

Abstract: Data may be encoded onto a direct current power line by modulating the current on that direct current power line. One method of modulating the current is by placing an inductor on the power line and then using a controlled transistor that turns on and turns off. The inductor will ensure that current keeps flowing but the transistor will induce changes in the current pattern. The excess current from when transistor is turned off must be diverted. Furthermore, to create symmetrical current changes, the inductor should be reverse biased. Thus, a circuit is created that sinks the excess current from when the transistor is turned off and used to reverse bias the inductor.

Abstract: An isolated flyback converter for an LED driver includes a snubber circuit unit connected to the primary side of a transformer; and a snubber voltage detection unit which detects a snubber voltage of the snubber circuit unit and generates a reference voltage proportional to the detected snubber voltage. Further, the isolated flyback converter includes a switching unit with a source terminal and a drain terminal, and may be turned on or off in response to an arbitrary logic signal. Furthermore, the isolated flyback converter includes a control unit which compares a voltage supplied through the switching current sensing resistor with the reference voltage, and supplies a logic signal at relatively high level or relatively low level to the switching unit to control the switching unit such that a secondary-side current of the transformer is maintained relatively constant.

Abstract: A lighting unit includes at least two channels of light sources, and a driver for the light sources. The driver includes a DC/DC converter and a control arrangement for controlling the current supplied to at least one of the two channels in response to a control signal produced by the DC/DC converter. Beneficially, a feedback loop controls a switching device in the DC/DC converter to maintain the light level produced by the light sources at a desired level regardless of changes in the supply voltage and the load.

Abstract: An alternating current-to-direct current (AC-to-DC) power supply has a first stage providing a first DC voltage and a second stage providing a second DC voltage. The AC-to-DC power supply has a first efficiency at the first stage and a second efficiency at the second stage that is less than the first efficiency. The second DC voltage is also less than the first DC voltage. A blower is electrically connected to the first stage of the AC-to-DC power supply to receive the first DC voltage from the AC-to-DC power supply to power the blower. Electrical connection of the blower to the first stage of the AC-to-DC power supply instead of to the second stage of the AC-to-DC power supply wastes less power and is more efficient.

Abstract: A light-emitting diode (LED) driver is adapted to control either the magnitude of the current conducted through a LED light source or the magnitude of a voltage generated across the LED light source. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting the magnitude of the current conducted through the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique. The LED drive circuit may comprise a controllable-impedance circuit, such as a linear regulator. The LED driver may be operable to control the magnitude of the bus voltage to optimize the efficiency and reduce the power dissipation in the LED drive circuit, as well ensuring that the load voltage and current do not have any ripple.

Abstract: A control circuit of a LED driver according to the present invention comprises an output circuit, an input circuit and an input-voltage detection circuit. The output circuit generates a switching signal to produce an output current for driving at least one LED in response to a feedback signal. The switching signal is coupled to switch a transformer. The input circuit samples an input signal for generating the feedback signal. The input signal is correlated to the output current of the LED driver. The input-voltage detection circuit generates an input-voltage signal in response to an input voltage of the LED driver. The input circuit will not sample the input signal when the input-voltage signal is lower than a threshold. The control circuit can eliminate the need of the input capacitor for improving the reliability of the LED driver.

Abstract: A lamp driver circuit to selectively energize one or more lamps is provided. The inverter circuit has a transformer with primary and secondary windings to provide voltage to the lamps. A filter is connected to the primary winding to receive a primary winding signal representative of the voltage across the primary winding. The primary winding signal has a frequency spectrum and the filter detects a particular characteristic of the frequency spectrum that is indicative of an end of life (EOL) condition of the one or more lamps. A control circuit is connected to the inverter circuit and to the filter. The control circuit is configured to discontinue energizing of the one or more lamps by the inverter circuit when the particular characteristic of the frequency spectrum of the primary winding signal is detected by the filter.

Abstract: An LCD backlight driving device with an isolating transformer comprises a DC power supply, a square wave generator, a square wave controller, said isolating transformer and a driver transformer; wherein said isolating transformer has a primary side connected to said square wave generator and a secondary side connected to said driver transformer, since said isolating transformer is placed between said square wave generator and said driver transformer, it helps to effectively shorten a safety distance required for setting up said driver transformer; the present invention uses said isolating transformer to shorten the safety distance required than that of using said driver transformer directly and to decrease an area in implementing a circuit board and to cut cost of said device.

Abstract: This invention relates to a luminaire comprising a light source emitting output light, and a detector unit, which is arranged to detect received light emanating from a remote reflection of said output light, wherein the detector unit comprises a first identifier, which is arranged to identify a remotely introduced reflector identifying light coding of the received light. The invention also relates to a method for determining a property of light at a remote position.

Abstract: A circuit for supplying a light source (L) such as a high flux (HF) LED with Pulse Width Modulation (PWM) dimming capability includes: a rectifier (10) for receiving an input bipolar PWM modulated signal (v) representative of a desired dimming level for the light source (L) and produce therefrom a rectified signal; a current regulator (14) to receive the rectified signal and produce therefrom a supply current for the light source (L); and a control module (16) sensitive to the input bipolar PWM modulated signal (v) to control the current regulator (14) to produce a PWM modulated supply current for the light source (L); and a capacitor (18) arranged between the rectifier (10) and the current regulator (14) to stabilize the rectified signal. The circuit typically includes ancillary circuitry (12), such as a microcontroller, connected to the capacitor to be supplied with the rectified signal as stabilized by the capacitor (18).

Abstract: The present invention relates to an inverter and a lamp driver having the same. The inverter includes a first switch having a first body diode, a second switch having a second body diode, a transformer including a first side coil in which a first current and a first voltage are generated according to switching operations of the first switch and the second switch and a second side coil having a predetermined winding ratio with respect to the first side coil, and a controller for controlling each switching operation of the first switch and the second switch. The controller turns on one of the first switch and the second switch corresponding to one of the first body diode and the second body diode, and a current flows through the first switch and the second switch during a dead time.

Abstract: An AC conversion circuit includes a main transformer having a primary winding and a secondary winding to electrically insulate the AC power source side and the discharge tube side from each other, an IC1 arranged on the AC power source side, a plurality of switching elements arranged on the AC power source side and driven by the IC1, to pass a current through the primary winding of the main transformer based on the DC power, an IC2 arranged on the discharge tube side, to generate a pair of rectangular-wave signals for conducting PWM control on a current passing through the discharge tube and having the same pulse width with a duty ratio of less than 50% and a phase difference of about 180 degrees, and one or more signal transfer insulated elements to send the pair of rectangular-wave signals from the IC2 to the IC1.

Abstract: A driving circuit for driving loads includes a switch circuit, a transformer, a current sensing circuit, and an inverter controller. The switch circuit and the transformer are used for converting a DC electric power to an AC electric power so as to energize the loads. The current sensing circuit coupled to the loads generates a feedback current signal indicative of a current flowing through the loads. The inverter controller includes a switch drive circuit, a current regulation circuit receiving the feedback current signal, and a mode controller circuit. The switch drive circuit controls the switch circuit so as to adjust power delivered to the primary winding of the transformer in accordance with the feedback current signal. The mode controller disables the switch circuit through the switch drive circuit if the external signal is in an absence state for a predetermined period.

Abstract: The invention relates to a resonant power LED control circuit for the independent, simultaneous brightness and color or color temperature control of two LEDs (41, 42) or two groups of LEDs, comprising a single resonant converter which is essentially formed from a half or full bridge DC/AC converter (2) with a control unit (21), a resonant capacitor, and a transformer (3).

Abstract: An apparatus for driving a lamp comprising at least one lamp, an inverter to supply an alternating current signal, a transformer to boost the signal from the inverter and to supply the boosted signal to the lamp, and a safety circuit to detect the signal flowing to the lamp and to compare the signal with a predetermined threshold to shut down the inverter in accordance with the compared result.

Abstract: A circuit includes a converter for converting an a.c. voltage into a d.c. voltage. The converter has a diode half-bridge, a switch half-bridge, and two d.c. rails. Further, the converter has a second converter for converting the a.c. voltage into a second d.c. voltage.

Abstract: A discharge-lamp control device for lighting a discharge-lamp includes two electrodes, first and second driving units to supply power to the discharge-lamp through the electrodes, respectively. Each driving unit includes a transformer having primary and secondary coils and a capacitor connected in parallel to the secondary coil. The first driving unit has impedance characteristics with a minimum impedance at a first frequency and a maximum impedance at a second frequency lower than the first frequency. The second driving unit has impedance characteristics having a minimum impedance at a third frequency and a maximum impedance at a fourth frequency lower than the third frequency. The first frequency is set to be higher than the third frequency. The second frequency is set to be lower than the fourth frequency. An operating frequency of the driving circuit is selected within a frequency bandwidth from the fourth frequency to the third frequency.

Abstract: A multi-lamp backlight system. The system includes a core, a first coil set wrapped around the core, to which a first AC voltage is applied, a second and third coil sets wrapped around the core and respectively disposed on two sides of the first coil set, on which a second and third AC voltage are induced by the first voltage signal applied to the first coil set respectively, wherein the numbers of coils of the second and third coil sets are substantially the same, and first and second lamps are supplied with power by the second and third AC voltages respectively.

Abstract: A ballast for a vehicle metal halide lamp is simplified using a DC-AC one-step-boost high frequency ballast system. To satisfy requirements specific to a metal halide lamp, a discharge developing capacitor is installed on a primary side of a transformer in parallel with a DC power supply, ensuring discharge development after a breakdown. To reduce the size and increase the operating voltage of the transformer, a booster circuit and voltage-doubler circuit are installed on the primary side and secondary side of the transformer, respectively. To reduce the size of the transformer and achieve a stable discharge, the ballast frequency is swept within a range between the specified minimum frequency and maximum frequency so that the center frequency is from 80 kHz to 120 kHz, and the same frequency is unsustained for more than 10 msec.

Abstract: The invention relates to a device (101) for switching on and powering discharge lamps comprising at least a current limiting device, at least a square wave generator, at least an igniter, at least two high tension connection cables (107, 107′), at least a lamp holder (103) with at least a discharge lamp (104) coupled, said at least one igniter comprising at least a high tension transformer and at least an overlapping transformer, said device being characterised in that said at least an igniter is divided into a first stage of the igniter, or pulse generator transformer (102), and a high tension transformer (108), and in that said first igniter stage, or pulse generator transformer (102), and the relevant high tension transformer (108) are assembled along with the above mentioned components.

Abstract: In a ballast circuit for operating a lamp, which comprises a bridge circuit and a control circuit for controlling the bridge switches, the control circuit comprises a microprocessor. The control signal for controlling the switches is generated by a separate circuit comprising a signal generator, a timer, two comparators and two reference signal generators. The microprocessor is used only to set the reference signals to the desired values, thereby dimming the lamp.

Abstract: An ignition system, of the type having ignition coils supplying energy to spark plugs in an internal combustion engine, includes apparatus to measure an electrical characteristic indicative of spark duration and generate a representative spark duration signal therefrom, or alternately to directly measure spark duration and generate a representative spark duration signal. Computational circuitry receives the spark duration signal and a spark duration setpoint signal, computes the error between the setpoint and the actual spark duration on a real-time basis, and modulates the energy in the high energy power supply to the ignition coils for maintaining a constant spark duration.

Abstract: A neon sign includes a transformer module and a receptacle attached to the neon sign for receiving the transformer module. The transformer module is configured to mate with the receptacle as the transformer module is plugged into the receptacle in order to connect the transformer module to the neon sign. The transformer module includes a high voltage transformer for transforming a primary input voltage into a secondary high voltage output. The transformer module also includes secondary contacts for connecting the secondary high voltage output of the transformer module to the neon sign when the transformer module is plugged into the receptacle. The receptacle also includes secondary contacts configured to mate with the secondary contacts of the transformer module as the transformer module is plugged into the receptacle thereby electrically connecting the secondary high voltage output of the high voltage transformer to the neon sign.

Abstract: An electronic ballast for a gas discharge lamp has a power source section for receiving a commercial AC to provide a DC voltage, and an inverter section, in response to a pair of switching driving signals, for switching and transforming an output voltage of the power source section at a high speed as an AC power source that is supplied to the gas discharge lamp. For controlling the switching of the inverter section, an inverter controlling section generates a pair of switching driving signals respectively having a predetermined dead time in a switching-ON time interval with a phase difference of 180 degrees from each other to supply them to the inverter section.

Abstract: A half-bridge inverter is powered from an ordinary electric utility power line by way of a full wave rectifier-filter means. The high frequency voltage output of the inverter is loaded with a series-combination of a tank inductor and a tank capacitor, with a fluorescent lamp being connected in parallel with the tank capacitor. The ON-time of each of the inverter's two transistors is shorter than half the period of the high frequency voltage; thereby preventing the two transistors from conducting simultaneously; thereby, in turn, protecting the inverter from self-destruction in case of lamp failure.

Abstract: A sun tanning apparatus has an electronic operating system comprising: (i) a plurality of pairs of fluorescent lamps for providing tanning radiation, each pair of lamps being adapted to be powered from 30 kHz/120 Volt by way of a high-Q series-resonant L-C ballasting circuit; (ii) a relatively low-power frequency converter connected with the power line and operable to provide power for heating the cathodes in these fluorescent lamps, thereby conditioning the lamps for easy starting; (iii) a relatively high-power frequency converter also connected with a power line and operable to provide the 30 kHz/120 Volt required for operating the plurality of pairs of fluorescent lamps by way of the high-Q series-resonant L-C ballasting circuit; and (iv) delay means operable to prevent the 30 kHz/120 Volt provided by the high-power frequency converter from being applied to the fluorescent lamps until after power has been applied to heat the lamp cathodes for at least one second.

Abstract: A power supply for an electric insect trap having an electrocution grid and a fluorescent lamp for attracting insects to the grid employs an inverter to generate a high frequency alternating voltage. The alternating voltage is applied across the primary winding of a first transformer having a secondary winding for development of a current-limited voltage for operating the lamp. Due to large inductance, the secondary winding functions as a constant current source to the lamp, so that lamps having different voltage characteristics may be used in the same circuit. A high voltage transformer has a primary driven by the limited lamp current to produce a high voltage for the electrocution grid across its secondary winding. Current limiting is achieved, in part, by providing a selected amount of flux leakage between the primary and secondary windings of the first transformer.

Abstract: A highly efficient, energy saving ballasting and transfer circuit, utilizing a single high frequency inverter ballast unit, capable of powering multiple lamp loads from any direct or alternating electric power source, comprises a current feedback inverter in combination with a leakage transformer, which operates to permit coupling of the single inverter unit to any number of lamps, particularly the gas discharge type. The leakage transformer can power any number of lamps from a single source which, because of its linear transfer function, achieves controlled light output of the lamps proportional to the power input. Thus, an excellent dimming capability is achieved. It is important to note that this leakage transformer is a special case of a certain type of multi-path leakage transformer, where only one secondary coil is used to achieve the same dimming capabilities of multiple secondary embodiments.

Abstract: A highly efficient, energy saving ballasting and transfer circuit, utilizing a single high frequency inverter ballast unit, capable of powering multiple lamp loads from any direct or alternating electric power source, comprises a current feedback inverter in combination with a unique multi-path, independently controlled leakage transformer, which operates to permit coupling of the single inverter unit to any number of lamps, particularly the gas discharge type. The multi-path leakage transformer provides multiple and independent magnetic circuits to power any number of lamps from a single source which, because of its linear transfer function, achieves controlled light output of the lamps proportional to the power input.