Abstract: An inventive isolated converter which exempts the auxiliary isolation devices with accurate voltage regulation is disclosed. The converter includes the primary side circuit with a primary controller controlling the on and off of the primary switch and a secondary side circuit with a secondary controller controlling the on and off of the secondary synchronous rectifier. The isolated converter uses the secondary controller to turn on the secondary synchronous rectifier after the secondary current decreases to zero to generate a negative tail current and turns off the secondary synchronous rectifier at a reference tail current peak value to generate a reflected negative current at the primary side circuit for turning on the primary switch.

Abstract: Methods and apparatus for driving discharge lamps are disclosed herein. In one embodiment, a method for driving a discharge lamp includes generating a switching signal to drive a discharge lamp, monitoring a working status of the discharge lamp, and determining whether the discharge lamp is operating abnormally based at least in part on the monitored working status. The method also includes decreasing a duty cycle of the switching signal when the discharge lamp is determined to operate abnormally.

Abstract: The present invention provides a method and apparatus for driving multiple parallel discharge lamps, which increases the switching frequency once the open lamp condition is detected to provide an output voltage that is high enough to ignite the lamp again.

Abstract: The present invention discloses a smart driving method for a secondary synchronous rectifier of an isolated converter and its apparatus thereof. The apparatus comprises: a main circuit having a secondary synchronous rectifier Q1; a differentiation filter circuit, filtering the drain-source voltage Vds of the secondary synchronous rectifier, comprising a capacitor and at least one resistor connected in series and outputting a filtered voltage Vf from either between said capacitor and said at least one resistor or between said at least one resistor; a smart driver, receiving Vf and Vds and putting out a driving signal to the gate of the secondary synchronous rectifier. The control approach is fulfilled by comparing Vds to a reference voltage Vthr2 and comparing the absolute value of Vf to another reference voltage Vthr3. When Vds<Vthr2 and |Vf|>Vthr3, Q1 is turned on. When Vds>Vthr1, Q1 is turned off, where Vthr1 is a predetermined reference voltage.

Abstract: A CCFL inverter circuit integrates a feedback circuit and protection circuit together. For both in-phase and out-of-phase applications, sensed lamp voltages can be used for open lamp and short lamp detection and sensed currents can be used for open lamp detection. The driving circuit adjusts the open lamp frequency by using a duty cycle control signal so that the driving circuit can always achieve the desired lamp voltage gain.

Abstract: The present invention discloses a Class-D power amplifier and control method thereof. In one embodiment, the amplifier feeds back the signal at the output node to the inverting input of the comparator, and provides a high frequency triangular wave signal to the non-inverting input of the comparator. In addition, the non-inverting input of the comparator may be coupled to an offset voltage, while the inverting input of the comparator may be coupled to a fixed-frequency rectangular wave signal, a feedback signal which is derived from the output stage and an input signal. In use, the switching frequency may be at least substantially fixed, so as to reduce the influence on the system caused by electromagnetic interruption (EMI). Further, the control circuit is simple, and some devices can be integrated.

Abstract: An inverter comprising a low-side switching element in series with a first primary winding; a high-side switching element in series with a second primary winding, where the combination of the low-side switching element and first primary winding is connected in parallel with the combination of the high-side switching element and the second primary winding; and a clamping capacitor having one terminal connected to the first primary winding and having a second terminal connected to the second primary winding. Other embodiments are described and claimed.

Abstract: The present invention discloses a DC/AC converter in the backlight power supply system using cold cathode fluorescent lamp (CCFL). The DC/AC converter comprises a front end DC/DC converter, a full-bridge or half bridge inverter, and a piezoelectric transformer. Even with a wide range of input voltages, the front end DC/DC converter produces a predetermined DC voltage or a DC voltage with a predetermined small range and the cascaded inverter operates with a switching frequency close to the resonant frequency of the piezoelectric transformer, which helps the backlight power supply system achieve high efficiency.

Abstract: An ink printer head of individual ink printer modules operating according to the edge-shooter principle equipped with piezoelectric actuators is provided for use in printers for postage meter machines and correspondingly has a large number of nozzles arranged in columns. An assembly has n ink printer modules arranged in registry side-by-side with ink chambers open toward a front side of the assembly with an adapter plate matched to the front face and having openings in registry with ink chambers is disposed adjacent the front face. A nozzle plate adapted to the adapter plate is disposed in front of the adapter plate. The nozzle plate is supported by the adapter plate and a spatial matching between the larger ink chambers and the smaller nozzles is achieved. Moreover, the two ink chamber columns of a module are united to form one nozzle column. A reduction in the manufacturing outlay while preserving the requiring printing precision is achieved.

Abstract: In a method and apparatus for producing an ink jet printer head composed of a number of stacked modules, a piezoactuator plate is formed by metallizing opposite major faces of a plate of piezoelectric material, while leaving an unmetallized stripe on one of said major faces, thereby separating the metallization on that major face into two regions. A side face of the piezoelectric plate is also metallized, the side face extending substantially parallel to the unmetallized stripe, thereby electrically connecting one of the metallized regions on one major face to the metallized layer on the opposite major face. The metallized piezoelectric plate is then structured so as to produce a number of side-by-side piezoactuators therein, each piezoactuator having first and second electrodes formed by the respective metallization on the opposite sides of the plate. Respective electrical leads for the two electrodes of each piezoactuator can be electrically contacted to the same side of the plate, i.e.

Abstract: An ink-jet printer head is composed of individual, stacked ink-jet printer modules operating according to the edge-shooter principle and equipped with plate-shaped piezoelectric actuators whose electrodes are contacted to leads of a ribbon conductor. The ink-jet printer head has a simplified structure and improved service properties and is composed of individual, identical ink-jet printer modules whose nozzle rows are arranged offset relative to one another and can be easily interchanged, because the carrier layer of the ribbon conductors enveloping the leads is reinforced and shaped in the region between neighboring ink-jet printer modules, so that the required spacing between the piezoactuators and between the nozzle rows of the ink-jet printer modules as well as an exact fixing thereof relative to one another are achieved. In this way, the ribbon conductors serve as a contact element, a spacer and an adjustment member for neighboring ink-jet printer modules.

Abstract: An ink-jet printer head is composed of stacked ink printer modules operating according to the edge-shooter principle and each equipped with plate-shaped piezoelectric actuators. The ink-jet printer head is for use in small, fast printers, suitable for use in a franking machine wherein a large number of nozzles are required. Plate-shaped spacer parts between the ink printer modules are structured such that they serve both for assuring the required spacing between neighboring modules as well as for setting an offset of the nozzle apertures of the neighboring ink printer modules relative to one another. To that end, the spacer parts are provided with registration elements at both sides that engage into allocated recesses of the ink printer modules. Each ink printer module also has electrical interconnects for connection to a driver circuit.

Abstract: In a method and apparatus for producing an ink jet printer head composed of a number of stacked modules, a piezoactuator plate is formed by metallizing opposite major faces of a plate of piezoelectric material, while leaving an unmetallized stripe on one of said major faces, thereby separating the metallization on that major face into two regions. A side face of the piezoelectric plate is also metallized, the side face extending substantially parallel to the unmetallized stripe, thereby electrically connecting one of the metallized regions on one major face to the metallized layer on the opposite major face. The metallized piezoelectric plate is then structured so as to produce a number of side-by-side piezoactuators therein, each piezoactuator having first and second electrodes formed by the respective metallization on the opposite sides of the plate. Respective electrical leads for the two electrodes of each piezoactuator can be electrically contacted to the same side of the plate, i.e.

Abstract: In a method and apparatus for producing an ink jet printer head composed of a number of stacked modules, a piezoactuator plate is formed by metallizing opposite major faces of a plate of piezoelectric material, while leaving an unmetallized stripe on one of said major faces, thereby separating the metallization on that major face into two regions. A side face of the piezoelectric plate is also metallized, the side face extending substantially parallel to the unmetallized stripe, thereby electrically connecting one of the metallized regions on one major face to the metallized layer on the opposite major face. The metallized piezoelectric plate is then structured so as to produce a number of side-by-side piezoactuators therein, each piezoactuator having first and second electrodes formed by the respective metallization on the opposite sides of the plate. Respective electrical leads for the two electrodes of each piezoactuator can be electrically contacted to the same side of the plate, i.e.

Abstract: An ink printer head of individual ink printer modules operating according to the edge-shooter principle equipped with piezoelectric actuators is provided for use in printers for postage meter machines and correspondingly has a large number of nozzles arranged in columns. For this purpose, a nozzle module, composed of a nozzle plate and two adapter plates arranged at opposite sides thereof, is disposed between ink printer modules that are constructed mirror-symmetrically relative to one another and are equipped with piezoactuators applied on both sides. The adapter plates are provided with openings for ink guidance and with recesses providing for the free space needed for piezoactuators. The openings in the adapter plates are matched, first, to the nozzle dimensions and, second, to the dimensions of the connecting channels to the ink chambers and are aligned with both the nozzles and the connecting channels. Identical etching masks can be used for a number of plates due to the mirror-symmetrical structure.