1563 results about "Triangular wave" patented technology

The protective helmet includes a rigid outer shell where the shell includes an undulating cross-sectional profile. A layer of impact-energy-absorbing material is positioned adjacent to the shell. The undulating profile of the shell can be any type of load spreading undulating profile, such as that of a sinusoidal or triangular wave configuration. The undulating load-spreading profile can be on the inner surface of the shell, on the outer surface of the shell or the entire cross-section of the shell may be undulating. The unique undulating profile makes the shell more rigid and spreads the impact load across the surface of the shell to thereby spread the deformation of the padding layer to prevent the shell from bottoming out of the impact-energy-absorbing material during an impact. As a result, a safer and more effective protective helmet is provided.

A method of inspecting a transparent container for refractive defects includes positioning a light source in spaced relationship with respect to a detector which is operatively associated with a processor for receiving electrical signals from the detectors responsive to light passing through the container being received by the detector. The method includes positioning a grid filter having a plurality of alternating dark and light bands adjacent the light source so as to provide a multiple intensity gradient to the container. The container is positioned between the light source and the detector with the grid filter serving to provide adjacent alternate light and dark bands of light impinging on the container. Refractive defects will cause a distortion of the intensity gradient which will be received by the detector. In a preferred embodiment, a plurality of light and dark bands are generally horizontally oriented and produces a generally triangular wave having a constant absolute slope. A processor is employed to receive the electrical signals emitted by the detector responsive to the light impinging thereon and make a determination as to whether refractive defects exist while ignoring desired irregularities in the container. Corresponding apparatus which employs alternating light and dark bands in the grid filter and in the preferred embodiment employs dark bands of single intensity gradient and light bands of single intensity gradient. Each band has a constant gradient of light intensity passing therethrough. The grid filters produces a triangular wave having a constant absolute slope.

A power amplifying apparatus which is of a switching type and capable of efficiently amplifying a power of an input AC signal such as an acoustic signal, includes a first switch circuit (11) and a second switch circuit (12) to which a power supply voltage Vc is applied, an inductor (13) and a load (14) which are connected between the switch circuits, and a control circuit (15) which receives an input AC signal Vi, sets a predetermined ratio of ON / OFF periods, and drives the switch circuits. The control circuit (15) includes an arithmetic circuit (20) which multiplies a modulation sensitivity (for example, an amplitude of a triangular wave voltage used for generation of a pulse signal for driving a switch circuit) by a ratio (Vc / Ec) of the power supply voltage Vc and a DC component Ec thereof. This configuration can compensate for distortion caused by a ripple variation of the power supply voltage due to regenerated power or the like, and enable a gain control by the power supply voltage.

A display panel which applies a PWM drive to a drive transistor (2) is provided. A drive transistor supplies current in accordance with its gate voltage, and the current is supplied to a light-emitting element (1) to illuminate the light emitting element. One end of a storage capacitor (6) is connected to the gate of the drive transistor, while the other end thereof is connected to a sweep line (12). A triangular wave which alternately repeats an up phase and a down phase is supplied to the sweep line in order to control an on period of the drive transistor in accordance with the gate voltage, to thereby control light emission of the light-emitting element.

A control device has a unit for preparing a pattern having first and second periods by comparing a triangular wave and a sine wave having an amplitude ratio set at each value of a modulation factor, and selecting one pattern corresponding to an instructed modulation factor, and a unit for applying a controlled voltage, set at low and high levels in response to first and second periods of the selected pattern, to a generator. The triangular wave has a cycle duration obtained by dividing the cycle duration of the generator by product of 3 and odd number, a crest having a level higher than the sine wave at a timing of each first period, and a trough having a level lower than the sine wave at a timing of each second period.

The invention relates to a constant time control method, a control circuit and a switching regulator using the same. The constant time control method includes: detecting output voltage of the switching regulator to obtain voltage feedback signals for representing the output voltage; detecting flow inductance current to obtain triangular wave signals for representing the inductance current; overlaying the triangular wave signals and the voltage feedback signals to generate a first control signal; calculating errors between the voltage feedback signals and first standard voltage, and compensating the errors to obtain a compensating signal; enabling the compensating signal to keep roughly constant; comparing the first control signal with the compensating signal to generate a second control signal; and controlling opening and closing of a power switching element in the switching regulator according to the second control signal and a constant time control signal so as to keep roughly constant of electric signals output by the switching regulator.

In a step-up / step-down DC-DC converter, an error signal commensurate with a difference between a voltage commensurate with the output voltage and a predetermined reference voltage and a triangular wave signal are compared by a first comparator, whose output is used to turn on and off a step-up switching circuit. An inverted signal obtained by inverting the error signal and the triangular wave signal are compared by a second comparator, whose output is used to turn on and off a step-down switching circuit. The median level between the outputs of the first and second comparators is set to be lower than the maximum level of the triangular wave signal and higher than the minimum level thereof. Thus, when step-up and step-down modes are switched from one to the other, an overlap period is produced during which the step-up and step-down modes overlap. This makes possible smooth switching between the step-up and step-down modes.

The invention relates to a high frequency heating apparatus that drives a magnetron such as a microwave, and provides a frequency modulation method of preventing harmonic current occurring due to a high frequency switching operation. When a driving signal is transmitted in order to drive a first semiconductor switching element (3) and a second semiconductor switching element (4), an inverter operating frequency in the every phase of a commercial power supply is provided as a frequency difference (inclination) of the phase range from 0° to 90° using a triangular wave-forming circuit in an oscillation circuit (16). A modulation waveform for a frequency modulation control is formed, configuring an upper limit clamp, a lower limit clamp, a lower limit value corresponding to the lowest frequency in a frequency modulation-forming circuit (15) on the basis of a commercial power rectifying voltage-dividing waveform after rectification. By combining these optimally, it is possible to prevent the harmonic current from occurring while forming the frequency modulation waveform handling several non-uniformities such as constants of major inverter circuit components or a power supply (Vcc) of a driving control IC unit (14).

An interrupt signal is generated at each of rising timings of PWM signals which are produced on the basis of phase-shifted triangular wave carrier signals for phases, and voltage command values for the phases. At timings of the interrupt signals, A / D conversion of motor currents of the phases detected by a shunt is started. Interrupt signals are also produced at timings of valleys of the triangular wave carrier signals. Additionally, peak interrupt signals and valley interrupt signals are respectively produced at timings of peaks and valleys of triangular wave carrier signals for phases. Based on each of the peak interrupt signals, normality / abnormality of a switching element of an upper side of the phase corresponding to the interrupt signal is checked, and, based on each of the valley interrupt signals, normality / abnormality of a switching element of a lower side of the phase corresponding to the interrupt signal is checked.

A buck-boost converter includes: a buck converter section including a first switch, a first rectifier, and an inductor; a boost converter section sharing the inductor and including a second switch, a second rectifier, and a smoothing circuit; and a control circuit for generating and outputting a first driving signal for opening and closing the first switch and a second driving signal for opening and closing the second switch. The control circuit includes: an error amplifier circuit for amplifying an error between an output value from the smoothing circuit and a predetermined voltage value to thereby generate and output an error signal; an oscillator circuit for generating and outputting a triangular wave signal having a predetermined cycle; a compensatory signal generation circuit for generating and outputting a compensatory signal, which oscillates in a cycle that is at least twice the cycle of the triangular wave signal; a control signal generation circuit for adding together the error signal and the compensatory signal to thereby generate and output a control signal; and a comparator circuit for comparing the triangular wave signal with the control signal to generate and output the first or second driving signal.

The present invention discloses a three electric level inverter control system. It contains three electric level voltage source inverter (NPC), field programmable gate array (FPGA), digital signal processor (DSP), wherein FPGA field programmable gate array (FPGA) receiving digital signal processor (DSP) sent control voltage instruction generating three electric level voltage source inverter (NPC) control signal. The present invention also discloses three level inverter control method, featuring 1, digital signal processor (DSP) transmitting space voltage vector amplitude value m and argument for controlling three level inverter triphase reference voltage, 2, field programmable gate array (FPGA) receiving DSP sent space voltage vector amplitude value m and argument, generating signal Vca, Vcb, Vcc, through direct current biasing and dead zone compensation techniques processing to generate three-phase voltage modulation signal Vca **, Vcb **, Vcc **, 3, finally respectively comparing with positive triangular wave, negative triangular wave to generate control pulse. The present invention overcomes the insufficiency of current pulse width modulation method (SVPWM) and special harmonic cancellation method (SHE-PWM), provides a fine rapidity, simple controlling, and practical three level inverter control system and method.

The use of a PLL including a phase detector responsive to the phase difference between an input signal and a feedback signal and which pilots an oscillator in function of this difference, is envisaged. The PLL also includes a feedback path that is responsive to the signal generated by the oscillator and which generates said feedback signal via at least one divider with a variable division ratio. The division ratio of said divider is modulated via a sigma-delta modulator, the input of which is fed with a triangular-wave modulating signal. The preferred application is that of a spread spectrum clock generator (SSCG) for digital electronic systems.

A carrier signal generation section is provided for each of U, V, and W phases, and each of the carrier signal generation sections has an up-down counter for counting clock signals output from a clock generator. An initial value is set for each of the up-down counters. When the up-down counters are simultaneously started by method of a count start signal output from a CPU, the respective up-down counters start counting operations from the respective initial values, perform cumulative subtraction until the count value reaches an upper limit, and perform cumulative addition until the count value reaches a lower limit. As a result, triangular wave carrier signals Cu, Cv and Cw of respective phases having a predetermined phase difference can be readily generated with high accuracy.

Choppers are provided respectively in the output stages of two diode bridges, and their output sides are connected in parallel to a smoothing capacitor. By controlling the operations of the two choppers, the currents which are allowed to be inputted to the diode bridges are made triangular waves of mutually opposite phases, or middle-phase waveforms of three phases.

A buck-boost converter includes: a buck converter section including a first switch, a first rectifier, and an inductor; a boost converter section sharing the inductor and including a second switch, a second rectifier, and a smoothing circuit; and a control circuit for generating and outputting a first driving signal for opening and closing the first switch and a second driving signal for opening and closing the second switch. The control circuit includes:an error amplifier circuit for amplifying an error between an output value from the smoothing circuit and a predetermined voltage value to thereby generate and output an error signal; an oscillator circuit for generating and outputting a triangular wave signal having a predetermined cycle; a compensatory signal generation circuit for generating and outputting a compensatory signal, which oscillates in a cycle that is at least twice the cycle of the triangular wave signal; a control signal generation circuit for adding together the error signal and the compensatory signal to thereby generate and output a control signal; and a comparator circuit for comparing the triangular wave signal with the control signal to generate and output the first or second driving signal.

A vehicle collision avoidance radar multi-target frequency matching method based on a combined waveform of an LFM triangular wave and a constant frequency wave belongs to the field of vehicle collision avoidance radar multi-target frequency matching, solves the technical problem of multi-target frequency matching, and eliminates constant false alarms. According to the technical scheme, over-threshold detection is carried out on upper and lower frequency sweep segments of the triangular wave and the constant frequency wave separately; beat frequencies of the upper and lower frequency sweep segments of the triangular wave are combined pair-wise and two matrices (A1 and B1) are generated; a difference matrix C1 of the matrix A1 and a first Doppler frequency value detected from the constant frequency wave is calculated, and the minimal value of the matrix C1 is found; and corresponding Doppler frequency values and beat frequencies and values in the matrix A1 and the matrix B1 are output. The beneficial effects are that the technical problem of multi-target frequency matching is solved and false alarms are removed.

A discharge-lamp lighting device is provided which decreases arc jumps, suppresses the fluctuation in brightness of the lamp, and prolongs a life of the lamp, by positively accelerating growth of spots even when an inexpensive, small and highly efficient lamp is used. A discharge-lamp controlling portion (101) sets frequencies of drive-controlling signals (A and B) for drive-controlling a commutator (109) within a predetermined frequency range so that spots formed by arc discharge on electrodes composing a high-pressure discharge lamp grow through a cycle of oxidation-reduction of a metal composing the electrodes, and superimposes a triangular wave signal generated on the basis of the drive-controlling signals onto a current-controlling signal (F) over an entire period of the drive-controlling signals so as to make a peak value of the triangular wave constant, thereby adjusting the waveform of current flowing in the high-pressure discharge lamp.

A DC-DC converting apparatus including a step-up and step-down circuit stepping up / down an input voltage to generate an output voltage and a PWM control circuit. The PWM control circuit generates an error signal, first to third voltages, a first triangular wave signal varying between the first and second voltages, and a second triangular wave signal varying between the third voltage and a fourth voltage determined based on the first to third voltages. The PWM control circuit compares the error signal with the first and second triangular wave signals and causes the step-up and step-down circuit to step up / down the input voltage based on the comparison. The first to fourth voltages V1 to V4 satisfy V1<V4<V2<V3 and V4=V3−(V2−V1). At least one of the first to third voltages is variably set to make a time in which voltage ranges of the first and second triangular wave signals overlap longer than a delay time caused by the comparison.

A discharge-lamp lighting device is provided which decreases arc jumps, suppresses the fluctuation in brightness of the lamp, and prolongs a life of the lamp, by positively accelerating growth of spots even when an inexpensive, small and highly efficient lamp is used. A discharge-lamp controlling portion (101) sets frequencies of drive-controlling signals (A and B) for drive-controlling a commutator (109) within a predetermined frequency range so that spots formed by arc discharge on electrodes composing a high-pressure discharge lamp grow through a cycle of oxidation-reduction of a metal composing the electrodes, and superimposes a triangular wave signal generated on the basis of the drive-controlling signals onto a current-controlling signal (F) over an entire period of the drive-controlling signals so as to make a peak value of the triangular wave constant, thereby adjusting the waveform of current flowing in the high-pressure discharge lamp.

The protective helmet includes a rigid outer shell where the shell includes an undulating cross-sectional profile. A layer of impact-energy-absorbing material is positioned adjacent to the shell. The undulating profile of the shell can be any type of load spreading undulating profile, such as that of a sinusoidal or triangular wave configuration. The undulating load-spreading profile can be on the inner surface of the shell, on the outer surface of the shell or the entire cross-section of the shell may be undulating. The unique undulating profile makes the shell more rigid and spreads the impact load across the surface of the shell to thereby spread the deformation of the padding layer to prevent the shell from bottoming out of the impact-energy-absorbing material during an impact. As a result, a safer and more effective protective helmet is provided.

The present invention discloses an electrical servo steering controller, which comprises a PID controller, a triangular wave generating circuit, a comparator, a motor current detecting circuit, a motor drive circuit, a microprocessor and a motor current setting circuit. Wherein, the PID controller outputs an adjusting voltage to the comparator according to a difference between a motor current setting signal output by the motor current setting circuit and a motor current detecting signal output by the motor current detecting circuit. The comparator compares a triangular wave signal output by the triangular wave generating circuit to output a pulse width modulation signal to the motor drive circuit to control the motor current. The microprocessor works out and controls a resistance value of a digital potential device in the motor current setting circuit to modify a servo characteristic. An analog circuit is adopted to complete main functions. Besides, a special motor drive chip can provide a higher servo force and ensure a larger applicable scope, simple circuit control, wonderful steering feeling and higher reliability.

A multiplicity of synchronized inverters for driving a multiplicity of loads such as CCFLs that require high ac voltages are arranged in close proximity of the respective loads and controlled in phase. A frequency determination capacitor and a frequency determination resistor are connected to one of the inverters to generate a triangular wave signal and a clock signal. The triangular wave signal and clock signal thus generated are supplied to other inverters to synchronize all the loads so that they can be controlled in phase. The resistance of the frequency determination resistor is set to a substantially small magnitude at the time of startup to increase the frequency of the triangular wave signal, thereby enabling quick startup of the loads.

Provided is a small-sized load drive system which, even with three three-phase inverters, significantly reduces noise regardless of control duty ratio. The load drive system includes three-phase inverters 301 to 303, and first, second, and third control units 401 to 403. The inverters 301 to 303 are connected to loads 211 to 213, respectively. The first control unit 401 generates sawtooth wave voltage and controls the inverter 301 according to the sawtooth wave voltage. The second control unit 402 generates inverse sawtooth wave voltage and controls the inverter 302 according to the inverse sawtooth wave voltage. The third control unit 403 generates triangular wave voltage which has ramps respectively equal to the sawtooth / inverse sawtooth wave voltage and either has a same phase or is out of phase by half a period relative to the sawtooth / inverse sawtooth wave voltage, and also controls the inverter 303 according to the triangular wave voltage.

The invention relates to a digital closed loop servo circuit applied to a quartz flexible accelerometer, which comprises a differential capacitor detection circuit, a triangular wave generating circuit, a pre-filtering amplifying circuit, an A / D conversion circuit, a D / A conversion circuit, a drive amplifying circuit and a digital signal processing circuit, wherein the triangular wave generating circuit is connected with the input end of the differential capacitor detection circuit, the differential capacitor detection circuit is connected with a differential capacitor of a meter mechanical part of the quartz flexible accelerometer, the differential capacitor detection circuit is connected with the pre-filtering amplifying circuit, the pre-filtering amplifying circuit is connected with the A / D conversion circuit, the digital signal processing circuit is connected with the A / D conversion circuit, the digital quantity output by the digital signal processing circuit is connected with a navigation computer through an output end and is connected with the D / A conversion circuit through the output end at the same time, the D / A conversion circuit is connected with the drive amplifying circuit, and a current signal output by the drive amplifying circuit is connected with a torque coil of the meter mechanical part of the quartz flexible accelerometer through the output end of the drive amplifying circuit.

The present invention provides a DC / DC converter that can include a capacitor constituting a soft start circuit in a semiconductor integrated device. This DC / DC converter is comprised of a switching element for supplying power from a power supply (Vcc) to a load side output terminal (OUT) by switching, an error amplifier for amplifying the voltage from the load side output terminal (OUT), a differentiation circuit for differentiating the voltage from the load side output terminal (OUT) and adjusting the output current according to the value thereof, a soft start circuit comprising a constant current source and a capacitor, both of which are connected to the output terminal of the differentiation circuit, and a comparator for comparing the triangular wave voltage from a triangular wave generator (TRI) with the voltage from the soft start circuit or the output voltage of the error amplifier, and controlling the switching of the switching element according to the comparison output thereof.