Abstract: A push-pull driver for powering fluorescent lamps in a backlight system includes a transformer with three primary windings to realize the advantages of both a push-pull switching topology and a full-bridge switching topology. The first and the second primary windings alternately conduct currents in opposite polarities to generate an alternating current signal to power one or more lamps coupled to a secondary winding of the transformer. The third primary winding is short-circuited to preserve energy stored in the transformer in a null state when both the first and the second primary windings are not conducting.

Abstract: An incremental distributed driver divides power delivered to multiple lamps into two power delivery stages. The first power delivery stage operates in voltage-mode to provide a partial operating voltage to the lamps. The second power delivery stage operates in current-mode to regulate current levels for each of the lamps and to provide additional operating voltages for the respective lamps. Each of the power delivery stages includes a polarity-switching network and a common set of driving signals from a controller can be used to drive the polarity-switching networks of both power delivery stages. The first power delivery stage delivers a majority of the power to the lamps and the second power delivery stage facilitates control of individual lamps while providing the remaining power to the lamps.

Abstract: In a bridge circuit for operating a high pressure discharge lamp an additional switching element, a control circuit for driving the additional switching element, a resonant inductor and a resonant capacitor are incorporated. The additional components together form a comparatively simple resonant igniter. The resonant inductor can be formed by part of a filter comprised in the bridge.

Abstract: A full bridge circuit including four switching elements (Q1 to Q4) is alternated with a high switching frequency and a series-connected resonance circuit (5) including an inductor (L2) and a capacitor (C2) is made to resonate at a switching frequency of the full bridge circuit multiplied by an integer (for example, frequency multiplied by three), thereby generating a high voltage pulse for start up. After a high-pressure discharge lamp (DL) is started up, the full bridge circuit is alternated with a low switching frequency so as to operate as a step-down chopper for inverting the output polarity, thereby stably supplying rectangular wave voltage of low frequency to the high-pressure discharge lamp (DL) via a filter circuit including an inductor (L1) and a capacitor (C1).

Abstract: A driver circuit or controller flexibly drives either a half-bridge or a full-bridge switching network in a backlight inverter without modification, redundant circuitry or additional components. The driver circuit includes four outputs to provide four respective driving signals that establish a periodic timing sequence using a zero-voltage switching technique for semiconductor switches in the switching network.

Abstract: A non-contact voltage detecting method and device are provided. The non-contact voltage detecting device includes a discharge lamp having an excitation voltage and a lighting voltage applied thereon, a boost circuit coupled to the discharge lamp for providing an operation voltage to the discharge lamp and a switch circuit coupled to the boost circuit for providing a periodical high-low signal level to control the boost circuit wherein the discharge lamp flickers if there is a relatively high voltage power nearby, while the discharge lamp is extinguished without the relatively high voltage power nearby. In addition, the device is capable of being an illumination source by increasing an input voltage of the boost circuit when it is not used for detecting the high voltage power.

Abstract: A discharge lamp driving apparatus comprises a DC power supply, a control circuit, switching elements, a step-up transformer, and a lamp current controlling circuit. In the discharge lamp driving apparatus, the secondary side of the step-up transformer is connected to multiple discharge lamps respectively via variable inductance elements, a series resonant circuit is constituted by a capacitor provided between the variable inductance element and the discharge lamp, leakage inductance of the step-up transformer, and inductance of the variable inductance element, and an output of the lamp current controlling circuit is connected to the variable inductance element, wherein the inductance of the variable inductance element is varied thereby controlling the lamp current of the discharge lamp.

Abstract: Disclosed is a solar powered lamp adopting a cold-cathode fluorescent lamp and an auxiliary startup device which can improve the efficiency of the voltaic-photo transformation when lighting the cold-cathode fluorescent lamp. The device comprises a direct current power unit, a DC/AC inverter circuit for generating a high voltage alternating current from the DC voltage to light a CCFL; and an auxiliary startup circuit disposed between the DC power supply unit and the DC/AC inverter circuit for generating across the input terminals of the DC/AC inverter circuit a voltage of about twice of the DC voltage output from the DC power supply unit.

Abstract: The invention relates to circuit arrangements for operating lamps and to operating devices which contain such circuit arrangements. A first stage of a circuit arrangement according to the invention comprises a SEPIC known from the literature. The SEPIC provides a DC voltage which an inverter converts to a radiofrequency AC voltage for lamp operation. According to the invention, an electronic switch (S1) acts both in the SEPIC and in the inverter. Two diodes (D1, D2), which are connected into the supply line for the electronic switch (S1), prevent the SEPIC and the inverter from influencing one another.

Abstract: The present invention relates to an electronic ballast that energizes fluorescent lamps connected in a parallel configuration. The ballast employs a power factor correcting boost converter that can be used over a wide range of AC line voltages to provide regulated power to a self-oscillating sine wave inverter that drives the fluorescent lighting load at high frequencies. The inverter employs special networks that limit a certain type of shoot-through current, and thus improve the efficiency of the unit. Also included is a restart circuit that limits power losses during the zero lamp condition, by periodically interrupting the inverter operation when the zero lamp state is detected. To improve operation of the power factor correcting circuitry over the wide range of AC line voltages, a DC offset is added to the sampled AC voltage at the higher AC line voltages by Zener diode based coupling circuit.

Abstract: An emergency lighting system powers all the luminaires of a lighting system during normal use, and switches from utility power to an emergency power source to drive some of the luminaires during a power outage. The typical on/off wall switch control for regular use carries out an automatic system test routine every time it is switched off. First, the non-emergency luminaires are extinguished, the emergency luminaires are activated for a time-limited period, and the system reverts to regular utility power and on/off control by the wall switch.

Abstract: In a voltage source according to the present invention, a switching transistor (Q1) is turned on when the voltage of an electrolytic capacitor (C1) exceeds a predefined positive voltage level (E1), to keep the electrolytic capacitor (C1) at the predefined voltage level (E1), and turned off when the voltage of the electrolytic capacitor (C1) is reduced below the predefined voltage level (E1). A switching transistor (Q2) is turned on when the voltage of an electrolytic capacitor (C2) is reduced below a predefined negative voltage level (?E2), to keep the electrolytic capacitor (C2) at the predefined voltage level (?E2), and turned off when the voltage of the electrolytic capacitor (C2) exceeds the predefined voltage level (?E2). Therefore, an output voltage (V3) is controlled between the predefined voltage level (E1) as an upper limit and the predefined voltage level (?E2) as a lower limit.

Abstract: A programmable oscillator comprises a capacitor; a current generator couplable to said capacitor that generates a charging current of said capacitor; further comprising at least one resistance coupled to said capacitor; a comparator coupled to said capacitor for comparing a voltage at the terminals of said capacitor with a prefixed reference voltage and for generating an output signal; a first switch, controlled by said output signal, coupled to said capacitor that creates a current path able to facilitate the discharging of said capacitor.

Abstract: A discharge lamp illumination circuit 1 has a DC-AC conversion circuit 3 which effects DC-AC conversion and boosting upon receipt of a DC input, and a starter circuit 4. The DC-AC conversion circuit 3 has an AC transformer 7, a plurality of switching elements 5H and 5L, and a resonance capacitor 8. The switching elements are activated by control means 6, thereby inducing series resonance between the resonance capacitor 8 and an inductance component of the AC transformer 7, or between the resonance capacitor 8 and an inductance element connected to the resonance capacitor 8. In connection with the operating frequency of the switching elements, a first frequency value is a frequency value of a period when outputs are open before the discharge lamp 10 is illuminated, and a second frequency value is a frequency value of a period from illumination of the discharge lamp by the starter circuit until elapse of a predetermined time period or a time period which is specified in accordance with an illumination state.

Abstract: An inverter is coupled to an EL lamp by a high pass filter including a series capacitor and a shunt resistor. The resistor is coupled in parallel with the EL lamp. The high pass filter has a time constant greater than 0.005 seconds and the capacitor has a capacitance at least ten times the capacitance of the EL lamp.

Abstract: A discharge lamp illumination circuit 1 has a DC-AC conversion circuit 3, which effects DC-AC conversion and boosting upon receipt of a DC input, and a starter circuit 4. Power output from the DC-AC conversion circuit 3 is controlled by means of control means 6. The DC-AC conversion circuit 3 has an AC conversion transformer 7; a plurality of switching elements 5H and 5L; and a resonance capacitor 8. The switching elements are activated by the control means 6, thereby causing serial resonance between the resonance capacitor 8 and a leakage inductance component of the AC conversion transformer 7, or between the resonance capacitor 8 and an inductance component 9 connected to the resonance capacitor 8.

Abstract: An electrical load power control device is described that reduces the power consumption of inductive and inductive-dissipative loads, including for example fluorescent lighting. The power circuit of the invention interrupts AC power supply to the load during a plurality of intervals within each half cycle of the AC mains signal frequency whilst providing an alternate path for current flow during the interruption to maintain a sinusoidal-like current to the load. During a crossover lag zone encompassing zero crossing points of the voltage and current and during which the voltage and current have opposite polarities, both elements of the power switch are switched to the “on” condition, one element of the circulating switch is switched to the “on” condition when a positive current is flowing in the load and the other element of the circulating switch is switched to the “on” condition when a negative current is flowing in the load.

Abstract: A multiplexed high voltage DC-AC driver including multiple DC-AC switches and decoder logic. Each DC-AC switch receives an input DC voltage and is operative, when enable, to toggle its output at a rate based on a master clock signal and at a voltage based on the input DC voltage. The DC-AC switches include one or more high side switches and a low side switch. The low side switch includes a clock inverter and operates out-of-phase relative to each high side switch. The decoder logic enables selected ones of the high side switches and enables the low side switch when any high side switch is enabled.

Abstract: A high-voltage oscillator including a first normally-on switch in series with a resonant circuit, a second normally-on switch in parallel with the resonant circuit, and a control circuit preventing the simultaneous conduction of the two switches.

Abstract: A switching power supply including a power factor correction circuit comprises a rectifier, an inductor coupled in series with the rectifier, a semiconductor switch formed by a compensation device coupled in parallel with the rectifier and the inductor. The output circuit comprises a diode coupled in series with a capacitor both coupled in parallel with the semiconductor switch. An input current sensor, and a control unit for controlling the compensation device are provided.

Abstract: An apparatus having a radio frequency resonator, which has a coil, a capacitor means and at least one switch means being associated with another capacitor means, a resistor means and a high voltage supply means, one end of the switch means being connected to a junction of the coil and the capacitor means where a radio frequency voltage is provided, another end of the switch means being connected to ground with said another capacitor means and to the high voltage power supply means with the resistor means.

Abstract: A liquid crystal monitor (LC monitor) illuminating apparatus utilizes a fluorescent lamp. The lamp is provided in a backlight portion to illuminate a liquid crystal monitor from behind. The fluorescent lamp is activated by a direct-current (DC) lighting circuit that is provided with a switching circuit which reverses the polarity of the DC lighting circuit. A digital camera with a liquid crystal monitor including an LC monitor illuminating apparatus is also disclosed.

Abstract: A switching device for operating a high-pressure discharge lamp with a voltage having successive periods of opposite polarity. The switching device includes input terminals for connecting a power supply source, output terminals for connecting the discharge lamp, a switch mode power supply and a control circuit for controlling the switch mode power supply, and a device for forming a lamp signal corresponding to the voltage present across the lamp. The switching device is provided with an arrangement for detecting a direct current through and/or a DC voltage across the high-pressure discharge lamp.

Abstract: A method and apparatus is disclosed to reduce power consumption of a load. In one embodiment a power control system selectively routes power directly to a load or to a power reduction device. A delay may occur prior to introduction of the power reduction device to fully energize the load. The power reduction device may operate in conjunction with signal modification device. The signal modification device modifies the signal provided to the load to achieve desired operation of the load. In one embodiment the power reduction device comprises a step-down transformer and the signal modification device comprises a capacitor. In one embodiment the power reduction device is selected to remove unwanted frequency components from the signal provide to the load. In various other embodiments the power control system may be configured to stagger start the load to minimize the peak draw of the load.

Abstract: An emergency illuminator includes a rectifying circuit for converting an input AC voltage to a DC voltage; an electric magnetic device having a primary side coil electrically connected to an output end of the rectifying circuit and a secondary side coil, wherein the secondary side coil becomes conductive when the AC voltage is interrupted; at least one lighting device having an anode electrically connected to a node of the secondary side coil of the electric magnetic device; a battery having a positive end electrically connected to the anode of the lighting device for providing the lighting device with working power; a control circuit electrically connected to a common end of the secondary side coil of the electric magnetic device, cathode of the lighting device, and a negative end of the battery.

Abstract: A method and apparatus for driving a ballast in critical discontinuous mode (CDCM). The method provides for zero loss switching in order to maximize efficiency, and also provides controllable input and output power without the use of complex and costly feedback loops.

Abstract: A self-oscillating boost converter includes a resistor-starting network configured to start a charging of the boost converter. A resonant feedback circuit is designed to generate an oscillating signal following the starting of the circuit by the resistor-starting network. A complementary switching network has a pair of complementary common-source connected switches configured to receive the oscillation signal generated by the resonant feedback circuit. The oscillation signal determines a switching rate, or duty cycle, of the complementary pair of switches. A boost inductor is in operational connection with the complementary pair of switches. The switching rate of the complementary switching network acts to determine the boost voltage supplied to a load.

Abstract: A full-wave driving circuit for multiple electroluminescent lamps includes circuitry at a collective first end of the electroluminescent lamps for boosting of both positive and negative waves, and control elements at second ends of the electroluminescent lamps for turning on/off individual lamps at different times, whereby single or multiple electroluminescent lamps can be driven to flash at the same time.

Abstract: A gas discharge lamp lighting device includes a DC/DC converter for adjusting electric power supplied from a power supply to generate and output a DC voltage, and an FET electrically connected to the DC/DC converter, for converting the DC voltage from the DC/DC converter to an AC voltage to be supplied to a gas discharge lamp. A control unit brings the gas discharge lamp to an electrode heating state in which both electrodes of the gas discharge lamp are heated after supplying the AC voltage to the gas discharge lamp. The control unit controls energy supplied to the gas discharge lamp in the electrode heating state according to a voltage across the gas discharge lamp. The control unit brings the gas discharge lamp to an AC discharging state in which an AC current flows through the gas discharge lamp after the energy has been supplied to the gas discharge lamp.

Abstract: A light emitting element driving circuit for high speed modulation includes an electric current source for generating a constant electric current for driving a light emitting element and an electric current switch for switching a portion of a path for an electric current flowing into the electric current source to one of a path including the light emitting element and another path excluding the light emitting element, in accordance with a data signal. The driving circuit further includes a capacitor that is charged by the application of a supply voltage to thereby boost the supply voltage, and a boost switching part. The boost switching part switches another portion of the path for an electric current flowing into the electric current source to one of a path for charging the capacitor and another path for applying the supply voltage boosted by the capacitor to the light emitting element, in accordance with a control signal corresponding to the data signal.

Abstract: A novel circuit for driving a high intensity discharge (HID) lamp uses pulse width modulation (PWM) switches to generate a signal to be delivered to a HID lamp. During different portions of the operating cycle, the system uses one switch to facilitate all PWM signaling, while the circuit uses two switching switches to generate the PWM signaling during other portions of the cycle operation.

Abstract: A hot restrike protection circuit provides complete shut down protection for a self-oscillating high intensity discharge lamp ballast of the type comprising a pair of complementary switching devices in a bridge configuration with a gate drive inductor in series with a second inductor, i.e., a control inductor, at the junction between the switching devices. The hot restrike protection circuit effectively comprises a three-terminal device for coupling across the control inductor. In particular, the HRP circuit comprises a sensing network for sensing voltage across the control inductor, a breakdown network for providing a breakdown path upon reaching a predetermined restrike voltage threshold across the control inductor, and a shutdown network for shutting down operation of the ballast until the lamp is sufficiently cool for restarting, thereby protecting ballast components during hot restrike, or re-ignition, of the lamp.

Abstract: The method of the present invention includes the first step of applying power to a character and/or image display apparatus and setting up input/output port values and initialization values, the second step of initializing all LED values and clearing a screen, the third step of reading initial picture data from a nonvolatile backup memory, the fourth step of writing the data read from the backup memory into a working memory, the fifth step of reading initialization data from the working memory, the sixth step of displaying an initial picture and performing a still mode until a rotation speed of a motor becomes stable, the seventh step of reading data other than the initialization data from the working memory, the eighth step of sequentially performing modes corresponding to commands contained in the read data, and the ninth step of repeating the above seventh and eighth steps until all commands stored in the working memory are processed.

Abstract: In a capacitive load drive circuit, in order to bring an output terminal used for supplying a drive voltage to a non-selected capacitive load into a high impedance state and in order to prevent the capacitive load from being unnecessarily driven by electric charge flowing to parasitic diodes at the output terminal, such as to prevent a non-selected electroluminescence element from turning on, a synchronizing unit generates second selecting signals by synchronizing first selecting signals to a clock signal constituting a basis of a drive signal of a common inverter for generating drive voltage to a common output terminal of plural electroluminescence elements, a drive signal generating unit brings individual output terminals into the high impedance state based thereon and a timing thereof is synchronized to a timing at which a potential difference between two poles of the non-selected electroluminescence element is nullified.

Abstract: An electronic ballast for a low-pressure discharge lamp (LA) contains an inverter that is fed with direct voltage (UBUS) and the output of which is connected to a load circuit containing terminal contacts for the lamp (LA), a heating transformer that has a primary winding (Tp), which is connected to the output of the inverter, and a respective secondary winding (Ts1, Ts2), which is located in a heating circuit with a coil (W1, W2), for heating each of the two electrodes of the lamp (LA), and a series circuit arrangement that is connected in parallel with the load circuit and which contains the primary winding (Tp) of the heating transformer and an electronic switch arrangement (S3, S4). For the purpose of identifying the type of lamp and the state of the lamp, the currents in one of the two heating circuits and in the primary winding (Tp) of the heating transformer are measured and evaluated.

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: A high frequency control circuit for a gaseous discharge lamp which includes a mechanically variable reactance device coupled in series with the lamp to control the current fed to the lamp. The mechanically variable reactance device is adjustable by a user to alter the intensity of the light emitted by the lamp.

Abstract: A ballast circuit for a gas discharge lamp with a tapless feedback circuit is disclosed. The ballast circuit comprises a d.c.-to-a.c. converter circuit with circuitry for coupling to a resonant load circuit, for inducing a.c. current therein. The converter circuit comprises a pair of switches serially connected between a bus conductor at a d.c. voltage and a reference conductor. The voltage between a reference node and a control node of each switch determines the conduction state of the associated switch. The respective reference nodes of the switches are connected together at a common node through which the a.c. current flows, and the respective control nodes of the switches are connected together. A gate drive arrangement regeneratively controls the first and second switches. It comprises a coupling circuit including an inductor for coupling to the control nodes a feedback signal representing current in the load circuit. It further comprises a tapless feedback circuit for providing the feedback signal.

Abstract: Unfiltered full-wave-rectified 60 Hz power line voltage is supplied to a first self-oscillating series-resonance-loaded inverter, the high frequency output current from which is magnitude-controlled, rectified and used for maintaining a substantially constant-magnitude DC voltage on an energy-storing capacitor. This constant-magnitude DC voltage is used in combination with the unfiltered full-wave-rectified 60 Hz power line voltage for powering a second self-oscillating series-resonance-loaded inverter, the high frequency current output from which is used for powering a fluorescent lamp load. By frequency-modulating the first inverter at a 120 Hz rate, the current drawn from the power line is made to be of such waveshape as to result in a power factor well in excess of 90% while at the same time having a content of under 20% of odd triplets of third harmonic currents. The high frequency current provided to the fluorescent lamp load has a crest factor not in excess of 1.7.

Abstract: A garage door mounted lighting system is provided including a garage with a side opening and a ceiling. The garage further includes a garage door slidably mounted along tracks extending along side edges of the opening and the ceiling for allowing the sliding of the garage door between an open orientation in parallel with the ceiling and a closed orientation for closing the opening of the garage. Further included is a light mounted on an inner face of the garage for illuminating upon the receipt of power. A switch is connected between a power source and the light for providing power to the light.

Abstract: The present invention relates to an integrated circuit adapted to perform the function of a diode of the DIAC type, the circuit having an input terminal and an output terminal. The circuit includes a first input transistor having a first terminal connected to a fixed voltage reference, a second terminal, and a control terminal coupled to the input terminal of the circuit. The circuit further includes second and third transistors in a current mirror configuration, each having a first terminal for coupling to the input terminal of the circuit, and a second terminal, and associated control terminals connected together and coupled to the second terminal of the first input transistor, the second terminal of the second transistor being connected to the control terminal of the first transistor.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and being connected together at a common node through which the a.c. load current flows. The first and second converter switches comprise respective interconnected control nodes respective reference nodes interconnected together at a common node. The voltage between each control node and associated reference node determining the conduction state of the associated switch. A voltage-limited energy source is connected between first and second nodes.

Abstract: Disclosed is a ballast circuit for a gas discharge lamp comprising a resonant load circuit incorporating the gas discharge lamp, a resonant inductance, and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the load circuit, and comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor. The switches are connected together at a common node through which the a.c. load current flows. The switches each have a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the switches are interconnected, and the respective reference nodes of the switches are connected together at the common node.

Abstract: The circuitry for operating a glow discharge path (GES) comprises a bridge circuit (BC) comprising a polarity switch (S1) and an ignition pulse circuit (ZIS1) in a first bridge branch (B1) and a polarity switch (S2) and an ignition pulse circuit (ZIS2) in a second bridge branch (B2). The glow discharge path (GES) formed between two electrodes (E1, E2) is located in the transverse branch of the bridge circuit (BC). For changing the polarity of the glow discharge path (GES), the polarity switch (S1) of the one bridge branch (B1) can be operated together with the ignition pulse circuit (ZIS2) of the other bridge branch (B2). Thus, each of the two electrodes (E1, E2) of the glow discharge path (GES) can be used as a cathode. The cathode of the glow discharge path is cleaned by the impinging ions.

Abstract: A back light circuit for a liquid crystal display (LCD) includes: an alternating current (AC) adapter, a battery for supplying a direct current (DC) when the alternating current (AC) adapter is not used, an adapter detecting unit for determining whether or not the alternating current (AC) adapter is being used, a direct current/direct current (DC/DC) converter for providing output of a switched signal, a direct current/alternating current (DC/AC) converter for driving a cold cathode fluorescent lamp (CCFL) by increasing an electric potential, a cold cathode fluorescent lamp (CCFL) operated by the direct current/alternating current (DC/AC) converter, an on/off controller for controlling the direct current/direct current (DC/DC) converter, a brightness controller for controlling the brightness of the cold cathode fluorescent lamp (CCFL), a feedback unit for providing feed back signals to the direct current/direct current (DC/DC) converter, a brightness condition detector for determining the brightness condition

Abstract: A low voltage power inverter utilizes reed switches to control a number of display tubes. The reed switches are controlled by magnetic coils or permanent magnets. The magnetic coils receive a control signal from a control circuit. The control circuit is powered by a capacitor coupled around a power lead and a capacitor coupled around a return lead. The permanent magnet is coupled to a mechanical actuator.

Abstract: In a circuit for driving a light emitting element, a switched capacitor circuit including a capacitor is connected between a power supply and the light emitting element. The capacitor in the switched capacitor circuit is charged to a power supply voltage when switches are exchanged to the sides of charging. The power supply is connected in series with the capacitor when the switches in the switched capacitor circuit are exchanged to the side of discharging. The power supply and capacitor connected in series therewith supplies the driving current to the light emitting element. Changing the number of times of exchange of the switches permits the driving current to flow into the light emitting element to be varied. Thus, the circuit for driving a light emitting element with excellent power-supply efficiency is provided which can drive a light-emitting element even when the power supply voltage for driving the light emitting element is lower than the forward voltage thereof.

Abstract: This invention is directed to an improvement of a field emission display architecture in which low-voltage row and column address signals control a much higher pixel activation voltage. Instead of using a pair of series-coupled transistors the emitter node grounding path as in the original architecture (one of which is gated by a column signal d the other of which is gated by a row signal), only a single transistor is utilized in the emitter node grounding path thus eliminating an intermediate node between the two transistors that was responsible for unwanted emissions under certain operating conditions. In a preferred embodiment of the invention, a current regulating resistor is placed in the grounding path in series with the primary grounding transistor, with the resistor being directly coupled to ground. Additionally, for the preferred embodiment of the invention, the gate of the grounding transistor is coupled via a second field-effect transistor to either a row signal or a column signal.

Abstract: A phase measurement apparatus and method for measuring electrical signal jitter and wander operates in real time and digitally controls bandwidths over which the measurements are performed. The apparatus includes a digital phase-lock loop (PLL) for generating phase difference signal data having first and second frequency components above and below the loop bandwidth of the phase locked loop. An analog-to-digital converter digitizes the analog phase difference signal from the phase detector. A digital signal processor (DSP) receives the digital data and performs a loop filter function for generating frequency update values to the DDS for phase locking the PLL to an incoming signal. The DSP performs an integration function on the loop filter function output to generate the second frequency components. The first and second frequency components are combined in a summing circuit and filtered in digitally programmable low and high pass filters for establishing measurement bands for measuring the phase difference.

Abstract: A circuit for repeatedly switching current through an inductor for driving an electroluminescent lamp at alternating voltage levels having both peak positive and peak negative polarities. This circuit includes a circuit path having two zener diodes in series connection with the lamp. These zener diodes each have an anode and a cathode, and a breakdown voltage, and may have either their anodes, or cathodes connected together. These zener diodes cause conduction along the circuit path in a first direction when a positive voltage driving the lamp exceeds the breakdown voltage of a first of the two zener diodes to provide a peak detection signal representing that the lamp has reached the peak positive polarity voltage level.