A sample support structure with integrated support features and methods of making and using the reinforced membrane. The sample support structures are useful for supporting samples for analysis using microscopic techniques, such as electron microscopy, optical microscopy, x-ray microscopy, UV-VIS spectroscopy and nuclear magnetic resonance (NMR) techniques.

One embodiment relates to an apparatus for electron beam lithography which includes a linear array of reflection electron beam lithography columns and a rotary stage. Each column is separately controllable to write a portion of a lithographic pattern onto a substrate. The rotary stage is configured to hold multiple substrates and to be rotated under the linear array of reflection electron beam lithography columns. Another embodiment relates to a method of electron beam lithography which includes simultaneously rotating and linearly translating a stage holding a plurality of wafers, and writing a lithography pattern using a linear array of reflection electron beam lithography columns over the stage. Each said column traverses a spiral path over the stage as the stage is rotated and linearly translated. Other embodiments, aspects and feature are also disclosed.

A coupling and various methods of use of the coupling. In one embodiment a coupling is provided for use with an appliance operated by a power supply, which coupling allows mounting/dismounting of the appliance without electrical isolation from the supply, said coupling comprising: a) a mounting member having a first encapsulated transformer element and suitable controls connectable to the power supply, said member being suitable for fixing to a structure; and b) a holder member engageable with said mounting member and suitable for holding or for connecting thereto an appliance, said holder member including a second encapsulated transformer element able to conduct power to an appliance.

A system for measuring properties of a surface under test with surface waves includes a surface wave network including a dielectric substrate, a reactive grid of a plurality of metallic patches on a first surface of the dielectric substrate, a plurality of electronic nodes on the first surface of the dielectric substrate, and a ground plane on a second surface of the dielectric substrate permeable to RF fields of the surface waves, and a controller configured for causing a respective one of the electronic nodes to transmit at least one surface wave and configured for collecting data for signals received by at least one other of the plurality of electronic nodes.

Systems and methods are disclosed herein to a radiation safety system comprising radiation emitting medical equipment; a radiation safety system controller connected to the radiation emitting medical equipment through a first communication means configured to determine a number of people within a radiation room housing the radiation emitting medical equipment and prevent the radiation emitting medical equipment from performing radiation emitting functions if the radiation safety system controller determines that more people than a maximum allowed number of people are presently in the radiation room; and a scanner connected to the radiation safety controller through a second communication means configured to detect people in the radiation room and communicate to the radiation safety system controller that a person has been detected.

A tunable laser source that includes multiple gain elements and uses a spatial light modulator in an external cavity to produce spectrally tunable output is claimed. Several designs of the external cavity are described, targeting different performance characteristics and different manufacturing costs for the device. Compared to existing devices, the tunable laser source produces high output power, wide tuning range, fast tuning rate, and high spectral resolution.

An approach is disclosed for acquiring multi-sector computed tomography scan data. The approach includes activating an X-ray source during heartbeats of a patient to acquire projection data over a limited angular range for each heartbeat. The projection data acquired over the different is combined. An image having good temporal resolution is reconstructed using the combined projection data.

A method and apparatus for acquiring data from a mass spectrometer and its transmission to a computer system including a data acquisition engine, a network interface and a throughput optimization module which includes a ring buffer and a protocol stack. A compression engine may be provided between the acquisition engine and the ring buffer. The ring buffer is configured as a number of segments containing portions of memory matching the size of data words from the acquisition engine. When a segment is full of data corresponding to the words, or is partially full and has received data containing an end of scan marker, the number of words in the segment is written into a header word in the segment and the data in that segment are moved to the protocol stack. Subsequent data is received by the next segment in the buffer.

An apparatus comprises a plasma flood gun for neutralizing a positive charge buildup on a semiconductor wafer during a process of ion implantation using an ion beam. The plasma flood gun comprises more than two arc chambers, wherein each arc chamber is configured to generate and release electrons into the ion beam in a respective zone adjacent to the semiconductor wafer.

Provided is an A/D converter including an input terminal, a reference signal line for supplying a reference signal which changes temporally, a comparator, a correction capacitor connected to an inverting input terminal of the comparator; and an output circuit which outputs digital data corresponding to an analog signal input to the input terminal. In a first state in which a total voltage of a first analog signal and an offset voltage of the comparator is held in the correction capacitor, a second analog signal input to the input terminal is supplied to a non-inverting input terminal of the comparator, and the second analog signal or the total voltage is changed using the reference signal, thereby outputting, from the output circuit, digital data.

In one aspect, an optical device comprises a monolithic optical module which includes a first total internal reflection (TIR) surface, a second TIR surface adjacent the first TIR surface, and a first optical port aligned with the first internal optical beam dividing interface. An interface between the first TIR surface and the second TIR surface forms a first internal optical beam dividing interface. An exterior surface of the first TIR surface and an exterior surface of the second TIR surface form a generally V-shaped notch on the monolithic optical module. A first optical beam entering the monolithic optical module through the first optical port and incident on the first internal optical beam dividing interface is partially reflected by the first TIR surface to travel in a first direction as a second optical beam and partially reflected by the second TIR surface to travel in a second direction as a third optical beam. The second direction is generally opposite to the first direction.

The present invention is directed to additives for coal-fired furnaces, particularly furnaces using a layer of slag to capture coal particles for combustion. The additive(s) include iron, mineralizer(s), handling aid(s), flow aid(s), and/or abrasive material(s). The iron and mineralizers can lower the melting temperature of ash in low-iron, high alkali coals, leading to improved furnace performance.

A pulverized coal burner and a pulverized coal boiler. The coal burner comprises a primary air cylinder (111) and a pulverized coal concentration device (112). The coal concentration device (112) makes the concentration of the coal flow gradually decrease from inside to outside along the radial direction, with respect to an axis (100) of the primary air cylinder (111). The coal burner further comprises a coal separating cylinder (113) and a coal guiding cylinder (114) located downstream of the device (112), the rear end of the cylinder (113) is connected with the front end of the coal guiding cylinder (114). The outlet of the cylinder (114) has a conical expansion portion (1141). The coal burner further comprises a divergent nozzle (115) connected with the rear end of the primary air cylinder (111) and whose cross-sectional area gradually increases along the flow direction of the coal flow.

The present invention provides grain-drying facilities which can effectively use the heat energy of a biomass combustion hot-air that has been generated in a biomass combustion furnace. The grain-drying facilities adopt technical means of providing the grain-drying facilities 1 which include: a biomass combustion furnace 3 provided with a heat exchanger 24 for generating hot air on the basis of a combustion heat of a biomass fuel and an outside air which has been taken in from the outside; and a circulation type grain-drying apparatus 2 provided with a grain-drying portion 7 to which the hot air that has been generated in the biomass combustion furnace 3 is supplied through a pipe 15 for supplying the hot air, wherein the above described circulation type grain-drying apparatus 2 has a grain-heating portion 6 which has a plurality of heating pipes 6a for heating the grains in the above described grain storing/circulating tank 5, and also has an air-exhaust fan 14 that is communicated with an exhaust side opening 6c that is located in one end side of each of the heating pipes 6a, and has a pipe 11 for supplying an exhaust hot-air, which communicates the exhaust hot-air sent from the above described biomass combustion furnace 3 with a supply side opening 6b that is located in the other end side of the heating pipe 6a.

A carbon fuel combustion process, employing an air gas separation unit, a combustion unit operating either with air or with an oxidizer leaner in nitrogen than air, coming from the air gas separation unit, and a unit for compressing and/or purifying the CO2 coming from the combustion flue gas, wherein the power consumed by the air gas separation unit and/or the flow of oxygen produced by the air gas separation unit and/or the capture of the CO2 coming from the combustion flue gas are variable over time is presented.

An ash basket can act as a sieve or strainer, allowing a user to lift out the charcoal from a kamado grill, clean out the ash, and place the ash basket back into the grill for future use. The ash basket retains larger pieces of charcoal that can be reused, while allowing the ash to pass through to a bottom plate of the grill. The bottom plate has openings to permit the ash to fall to an ash collection chamber. Without the ash basket, pieces of charcoal can block the openings in the bottom plate, making ash collection difficult. Moreover, with the openings blocked, proper air flow through the openings. Finally, the ash basket creates and additional air space that covers the entire surface of the interior walls by separating the ash from the wall, improving air flow, which is critical to the kamado grill design.

An apparatus for synergistically combining a plasma with a comminution means such as a fluid kinetic energy mill (jet mill), preferably in a single reactor and/or in a single process step is provided by the present invention. Within the apparatus of the invention potential energy is converted into kinetic energy and subsequently into angular momentum by means of wave energy, for comminuting, reacting and separation of feed materials. Apparatuss of use of the apparatus in the practice of various processes are also provided by the present invention.

A waste disposal plant includes a combustion chamber (2) inside which waste laid on a combustion grate (3) is burnt, which permits the entrance of an adequate quantity of combustion air in the chamber. The combustion grate includes at least a handling group formed by of fire bars or plates (7), which move alternatively one with respect to the other by advancing the waste on the grate. A handling group permits the alternate movement of the fire bars (7) which are divided in movable fire bars (7a) and fixed fire bars (7b), alternately disposed one with respect to the other, on transversal rows resting one upon the other according to a longitudinal placement with alternate steps.

A combustion device in the form of an elevated fixed-grate that includes arcuately shaped solid refractory brick with ribs placed thereunder so as to allow horizontal air flow for fuel combustion. The brick are arranged atop one another in a stacked concentric configuration that forms a central fuel passageway and allows cascading of a fuel pile throughout the combustion stages. The device provides the benefit of proper de-ashing online while distributing the underfire air radially around the fuel pile. The elevated design of the bricks allows the air to be evenly distributed throughout the fuel pile and further allows the isolation of overfire and underfire air. Segregating overfire and underfire air in an evenly distributed manner allows the burner to combust a wide range of fuel moisture contents without modifying the mechanical components of the burner.

The invention relates to solid fuel units having a fuel supply chamber wherein the fuel to be sent for combustion to the combustion region found in the body is placed and the feed mechanism carrying the solid fuel found in the chamber forward. It is characterized in that it includes a main burning block having a fuel and air cell connected to the solid fuel supply chamber and air outlet vents formed on the external wall surface. A preventive surface is positioned on the main burning block external wall surface in a way that it would form a closed volume in a certain distance.

Methods and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells are provided. A photovoltaic (PV) device generally includes a window layer; an absorber layer disposed below the window layer such that electrons are generated when photons travel through the window layer and are absorbed by the absorber layer; and a plurality of contacts for external connection coupled to the absorber layer, such that all of the contacts for external connection are disposed below the absorber layer and do not block any of the photons from reaching the absorber layer through the window layer. Locating all the contacts on the back side of the PV device avoids solar shadows caused by front side contacts, typically found in conventional solar cells. Therefore, PV devices described herein with back side contacts may allow for increased efficiency when compared to conventional solar cells.

This invention is directed to a flexible solar cell photovoltaic module with high light transmittance based on modified substrate, which belongs to the field of thin-film solar cell technology. The objective of the present invention to provide a technical solution for a transparent flexible solar cell module and its fabrication method. Technical features include using a stainless steel template to mold a modified polyimide PI substrate (the PI substrate). The PI substrate has light-passing through-holes, including draining holes and convergence holes, through and distributed on the PI substrate, a conductive film layer, and various stacked photoelectric conversion film layers. The creativeness of the present invention is obvious, such as reducing the short circuit and current leakage due to crystallization of the photoelectric layer interface caused by a subsequent process of laser etching the conductive film layer, reducing the composition on the surface of the solar cell, reducing steps of the fabrication process, and lowering the production cost. Further, the present invention significantly increases the conversion efficiency and load capacity of the solar cell and the quality-cost ratio. The transparent flexible solar cell photovoltaic module also has a broad range of applications.

A resin composition, a multi-layered film, a backsheet for photovoltaic modules, a method thereof, and a photovoltaic module are provided. The multi-layered film including a coating layer including a fluorine-based polymer has an excellent durability and weather resistance, and also exhibits high interfacial adhesive strength to a substrate since the multi-layered film is formed by coating a cured product of the resin composition including the fluorine-based polymer, an acrylic polymer including a thermosetting functional group, and a heat-curing agent on the substrate. In addition, drying can be performed at a low temperature during the manufacture of the multi-layered film so that the manufacturing costs can be decreased, productivity can be increased, and the deterioration of the product due to heat modification, heat shock, and the like, can be prevented. The multi-layered film can be effectively used as a backsheet for various photovoltaic modules.

A layered compound-metal particle composite 3 is obtained by the addition, to an organically modified layered compound 1 formed by the intercalation of organic ions between layers of a layered compound, of both an aqueous colloidal metal solution 2 in which metal particles are dispersed as a metal colloid in water, and a nonaqueous solvent which is a poor solvent for the metal colloid and has an excellent ability to swell the organically modified layered compound 1.

The present invention provides a dye-sensitized solar cell which enhances an area of a photo electrode by arranging metal wires on a surface of a transparent substrate or a transparent conductive layer without degrading a transparency of the solar cell, allowing the metal wires to act as a collector electrode exclusively or together with a metal electrode.

A back electrode type solar cell in which a no-electrode-formed region where no electrode is placed is provided in a part of a peripheral portion of a back surface of the back electrode type solar cell such that a line connecting end portions of a plurality of electrodes to one another includes a partially inwardly recessed region and the no-electrode-formed region is located adjacent to each of an electrode for n-type and an electrode for p-type adjacent to each other, a solar cell module, a method of manufacturing a back electrode type solar cell with interconnection sheet, and a method of manufacturing a solar cell module are provided.

A separate connection device (40) intended to be inserted between a metal frame (3), of an electrical component (1), and a metal supporting structure (20) in order to connect, electrically and separately, the frame to the supporting structure. The connection device (40) comprises a metal blade manufactured from spring steel which comprises two self-connecting end areas (45, 46) arranged in separate planes and comprising a set of sharp teeth (47) arranged in order to be embedded within the metal material and formed on a folded section of the metal blade so that the sets of teeth (37, 47) extend in opposite directions and in planes intended to intersect the planes of the frame (3) and of the supporting structure (20) when the connection device is mounted.

A light guide apparatus includes a light guide layer having a top surface and a bottom surface, and a transversely oriented side-end surface that forms an output aperture of the light guide, characterized by an index of refraction, n1, and further characterized by a length dimension in an intended light propagation direction towards the output aperture, where the intended light propagation direction is a z-axis direction of a Cartesian coordinate system; and a plurality of light injection elements disposed in the form of at least one linear strip in at least one of the top and bottom surfaces of the light guide layer, wherein some of the plurality of light injection elements are disposed on one lateral side of the strip and some other of the plurality of light injection elements are disposed on an opposing lateral side of the strip at a rotation angle Δz about the y-axis.

The present disclosure relates to gel-type polymer electrolyte for a dye-sensitized solar cell, a dye-sensitized solar cell comprising the gel-type polymer electrolyte, and a method for manufacturing the dye-sensitized solar cell.

A novel method and apparatus for performing the method is disclosed the apparatus comprises a laser (17), at least one ink jet print head (14), means for holding a transparent substrate having a transparent conductive layer, means (22) for adjusting the relative positions of the laser and at least one ink jet print head to the transparent conducting layer (2) and a controller to control the laser and ink jet print head whereby in a first step to inkjet print one or more coarse metal borders (15) onto the deposited TCM layer and in a second step by means of a single laser ablation process, ablating tracks in both the metal border and underlying TCM layer to form a plurality of discrete electrical busbars (12) and optionally also to form electrodes in the remainder of the TCM layer.

Provided is an organic light emitting device. The organic light emitting device comprising a first light emitting part on a substrate, emitting a first light of a first wavelength, wherein the first light emitting part includes a transparent first electrode, a first organic light emitting layer, and a transparent second electrode sequentially stacked on the substrate, a second light emitting part on the first light emitting part, emitting a second light of a second wavelength, wherein the second light emitting part includes a transparent third electrode, a second organic light emitting layer, and a reflective fourth electrode sequentially stacked on the first light emitting part, and a fluorescent material disposed at least one between the substrate and the first light emitting part, and between the first light emitting part and second light emitting part.

A tape feeder includes a guide part that guides a carrier tape and is detachably attached to a main body. The guide part includes: a lower member guiding the carrier tape and attached to and detached from the main body; an upper member pressing down the carrier tape from above; a tape introduction part guiding the carrier tape into the upper member at an upstream side thereof in a tape feed direction; a confirmation opening part disposed in the upper member for visually confirming that the carrier tape arrives at a pin engagement range; an open/close mechanism opening and closing the upper member with respect to the lower member; and a positioning mechanism fitting a positioning pin into a feed hole of the carrier tape in the guide part, thereby positioning the carrier tape relative to the guide part in the tape feed direction.

A vacuum roller for a web handling system comprises a hollow, cylindrical, rotably driven drum and an end cap threadingly mounted onto the rear end of the drum. Together, the drum and the end cap define a plurality of individual, externally communicable vacuum paths. A spherical, metal movable element is internally disposed within each vacuum path and regulates the passage of air therethrough. A plurality of magnetic elements is fixedly mounted on a stationary annular holder. In use, each magnetic element selectively displaces each movable element when disposed in close proximity thereto to the extent necessary so as to permit the passage of air through its corresponding vacuum path. As such, the vacuum roller is provided with a predefined range of suction, or vacuum zone, about the outer surface of its rotating drum that directly corresponds to the angular arrangement of the plurality of stationary magnetic elements.

A wire-processing machine or apparatus includes a wire-feeding apparatus for guiding a wire, wherein the wire-processing machine or apparatus contains a wire drive for forward movement of the wire and a guide pipe with an entry opening and an exit opening. The wire-processing machine or apparatus contains a swivel unit with drive and a wire-gripping apparatus which is arranged on a swivel arm, wherein an exit side end of the guide pipe is fastened to the swivel arm. The wire drive and the guide pipe are arranged in such manner that the wire can be shot-in through the guide pipe. The wire-feed apparatus further contains a length-compensating unit which is arranged in the area of the guide pipe and which, in a first state, shortens an effective length of the guide pipe and, in a second state, lengthens the effective length of the guide pipe.

The invention relates to a packaging machine, in particular a thermoformer, traysealer, comprising at least two transport chains for transporting a web of material, such as a film or the like. The packaging machine is characterized in that sensor means are provided for detecting the chain length and/or the chain pitch and/or the chain tension of the transport chains, means being provided for stretching and/or relaxing at least one individual transport chain, and control means being provided for adapting different lengths or chain pitches of two transport chains by stretching and/or relaxing at least one transport chain in a controlled manner.

A dispenser for dispensing paper toweling. The dispenser including a towel support that is positionable in a first dispensing position when a drive roller rotates in a first direction, and that is positionable in a second auto-loading position when the drive roller rotates in a second direction. Rotation of the drive roller in the first and second directions automatically loading the paper toweling for subsequent dispense.

A flexible and continuous substrates-conveying sheet has a plurality of to be processed substrates disposed on or in it. A nondestructive transferring unit includes a plurality of first transferring rolls and a plurality of second transferring rolls. The first transferring rolls make contact with a first surface of the substrates-conveying sheet where that surface can have electrostatically-induced charge formed thereon. Each of the first transferring rolls includes a first central portion charged with a positive electric charge and a first outer portion surrounding the first central portion. The second transferring rolls make contact with the first surface of the substrates-conveying sheet. The second transferring rolls are disposed alternately with the first transferring rolls. Each of the second transferring rolls includes a second central portion charged with a negative electric charge and a second outer portion surrounding the second central portion.

A phase-locked loop double-point modulator may include a frequency divider having a ratio which can be changed by a first modulation signal, and an oscillator, a frequency of which can be changed by a second modulation signal correlated to the first modulation signal. A calibration circuit may be configured, in a calibration mode, to match the gains of the first and second modulation signals based on frequency measurements of the oscillator for two different calibration values of the second modulation signal. The phase-locked double-point modulator may also include an attenuator having a constant ratio greater than 1 and placed in the path of the second modulation signal, and a selector switch configured to be controlled by the calibration circuit to reduce the ratio of the attenuator in the calibration mode.

An amplifier receives an amplitude signal of a polar modulated signal at a base terminal of a transistor and receives a phase modulated carrier signal of the polar modulated signal at the base terminal of the transistor. The amplifier combines the amplitude signal and the phase modulated signal to produce a full complex waveform at a collector terminal of the transistor.

A modulator generates a baseband digital signal from an information-bearing digital signal. The baseband signal has time-varying phase and amplitude defined by a sequence of complex data words, each having an in-phase (I) component and a quadrature (Q) component. A noise-shaping modulator generates a noise-shaped digital signal from the baseband digital signal such that quantization noise in the noise-shaping modulator is attenuated by a spectral null of its noise transfer function. The spectral null is selected by a noise-shaping parameter corresponding to a selected one of a plurality of output frequencies. A signal converter generates an analog signal conveying the information of the information-bearing digital signal on an analog carrier signal having the selected output frequency.

A signal generator for a transmitter or a receiver for transmitting or receiving RF-signals according to a given communication protocol includes an oscillator and a mismatch compensator. The oscillator is configured to provide a signal generator output signal having a signal generator output frequency and comprises a fine tuning circuit for providing a fine adjustment of the signal generator output frequency based on a fine tuning signal and a coarse tuning circuit for providing a course adjustment of the signal generator output frequency based on a coarse tuning signal. The mismatch compensator is configured to receive the signal generator output signal and compensate a frequency mismatch between a desired signal generator output frequency and the signal generator output frequency generated by the oscillator by providing the fine tuning signal for changing the state of the fine tuning circuit of the oscillator and by providing the coarse tuning signal for changing a state of the coarse tuning circuit of the oscillator. The mismatch compensator provides the coarse tuning signal during a guard period defined in the given communication protocol, during which no RF-signals are transmitted by the transmitter or no RF-signals are to be received by the receiver, such that the state of the coarse tuning circuit is changed within the guard period.

Parallel/serial conversion is performed on an N (where N is a natural number)-bit first parallel data signal with a first converted clock acquired by multiplying a reference clock by N, and parallel/serial conversion is performed on an (N×K)-bit (where K is a natural number) second parallel data signal with a second converted clock acquired by multiplying the reference clock by N×K.

A method for tuning a digital compensation filter within a transmitter includes: obtaining at least one resistance-capacitance (RC) detection result, wherein the digital compensation filter includes an RC compensation module; and tuning the digital compensation filter by inputting the RC detection result into the RC compensation module. For example, the RC detection result may correspond to a detected value representing a product of a resistance value and a capacitance value. In another example, the at least one RC detection result may be obtained by performing RC detection on at least a portion of the transmitter without individually measuring resistance values of resistors therein and capacitance values of capacitors therein. An associated digital compensation filter and an associated calibration circuit are also provided.

A new coded continuous phase modulation (CPM) scheme is proposed to enhance physical layer performance of the current DVB-RCS standard for a satellite communication system. The proposed CPM scheme uses a phase pulse design and combination of modulation parameters to shape the power spectrum of CPM signal in order to improve resilience to adjacent channel interference (ACI). Additionally, it uses a low complexity binary convolutional codes and S-random bit interleaving. Phase response using the proposed CPM scheme is a weighted average of the conventional rectangular and raised-cosine responses and provides optimum response to minimize frame error rate for a given data rate.

A PWM circuit that can have two refresh rates, including: a first PWM signal generator and a second PWM signal generator; wherein the first PWM signal generator and the second PWM signal generator respectively control refresh rates in two dimensions of an output data generated from a target apparatus. A PWM signal generation method that can have two refresh rates, including: generating a first PWM signal; generating a second PWM signal; and controlling refresh rates in different dimensions of an output data generated from a target apparatus respectively by using the first PWM signal and the second PWM signal.

A digital pulse width modulation controller includes a pulse width modulation controller, a selection unit having at least one selector, a comparison unit having at least one comparator, and a signal conversion unit having at least one digital-to-analog converter. The digital-to-analog converter generates a reference current and/or voltage. The comparator receives the reference current and/or voltage, and performs a comparison operation to generate a comparison signal based on a feedback signal. The selector selects one selection signal to input into the pulse width modulation controller, which receives other parameters set by a user or the system at the same time so as to control characteristics of the digital pulse width modulation signals, thereby improving the electric properties of a loading circuit.

A circuit includes a switched modulator stage combining an information signal with a square wave carrier to produce a first modulated signal; and a second modulation stage forming additional steps in the first modulated signal to produce a second modulated signal.

A rail-to-rail comparator including a first comparison unit connected to a first terminal and configured to compare differential input signals to differential reference voltages; a second comparison unit connected to a second terminal and configured to compare the differential input signals to the differential reference voltages; and an output unit configured to be driven in response to a clock signal and to generate a complementary output signal according to comparison results of the first and second comparison units.

An example PWM includes a driver and a two-way oscillator. The oscillator includes, a first frequency adjust current source, a second frequency adjust current source, a capacitor, a switching reference and a comparator. The capacitor integrates a frequency adjust current by charging with the first frequency adjust current source. The capacitor subsequently integrates a second frequency adjust current by discharging with the second frequency adjust current source. The switching reference outputs a first reference voltage and a second reference voltage responsive to an oscillator signal. The comparator compares the output of the switching reference with a voltage on the capacitor. The first and second frequency adjust current sources vary the first and second frequency adjust currents to vary the frequency of the PWM signal to spread energy of switching harmonics over a frequency band and to reduce EMI.

A time-varying formant is generated at a formant frequency by generating first and second harmonic phase signals having first and second harmonic numbers, respectively, in relation to a modulation frequency. The first and second harmonic phase signals are generated in proportion to a master phase signal, which varies at the modulation frequency, modulo a factor corresponding to their harmonic numbers. First and second sound signals, based on the first and second harmonic phase signals, are frequency modulated to create an arbitrarily rich harmonic spectrum, depending on an FM index. The time-varying formant is generated by generating a time-varying combination of the first and second harmonic sound signals, weighting the first and second harmonic sound signals in accordance with their spectral proximities to the formant frequency. One or more of the harmonic numbers are updated when the time-varying formant frequency passes the frequency of either sound signal.