832results about "Pulse technique" patented technology

In a switching power supply apparatus for performing a switching control of a power MOS transistor that flows current to a coil and converting input voltage into output voltage, even if there occurs offset voltage in a current sensing operational amplifier, source potential of a current sensing MOS transistor is precisely kept at source potential of a low side power MOS transistor. For example, an offset cancel capacitor is arranged at an inverting input terminal of the current sensing operational amplifier, and voltage in the direction to offset the offset voltage occurring in the operational amplifier is charged to this capacitor.

An input device includes a touch panel with which a user performs an input operation of information by touching the touch panel. The input device further includes a vibration generation device for feeding back, to the user, various kinds of sense of touch in accordance with the type of the information through the touch panel. Additionally, the input device includes a vibration control circuit for allowing the vibration generation device to generate various forms of vibrations in accordance with the type of the information. The vibration generation device is a bimorph piezoelectric actuator including a first actuator unit and a second actuator unit stacked on the first actuator unit in which when one of the first and second actuator units expands, the other contracts. Further, each of the first and second actuator units has a multi-layered piezoelectric element layer.

A pointing device including a touching surface, a light emitting diode, an imaging element, and a first light control part. A fingertip is placed on the touching surface. The light emitting diode illuminates the touching surface from a side opposite to a side where the fingertip is placed. The imaging element receives light reflected from the fingertip. The first light control part controls light, which is emitted from the light emitting diode and reaches the touching surface, so that the light is evenly incident to the touching surface. The pointing device improves detection accuracy and prevents malfunctions, even when there is deviation in an output from a light source. In addition, an electronic apparatus including an input device can be provided.

A load control device for controlling the amount of power delivered to an electrical load from a source of AC power comprises a controllably conductive device and a variable gate drive circuit. The controllably conductive device is coupled in series electrical connection between the source and the electrical load to control the amount of power delivered to the load. The variable drive circuit is thermally coupled to the controllably conductive device and provides a continuously variable impedance in series with the control input of the controllably conductive device. The impedance of the variable drive circuit is operable to decrease as a temperature of the controllably conductive device increases and vice versa. Preferably, the variable drive circuit comprises an NTC thermistor. Accordingly, the switching times of the controllably conductive device, i.e., the times when the controllably conductive device is changing between the conductive and non-conductive states, remain constant, or alternatively decrease, as the temperature of the controllably conductive device increases.

A circuit (800) for controlling at least one piezoelectric actuator (142) includes a piezoelectric drive circuit (802) that generates unidirectional voltage drive signal, also referred to as Vout, at node (804). The piezoelectric actuator drive circuit (802) includes a boost switcher circuit or charging circuit (806), a buck switcher circuit or pulsed current sink discharge circuit (808) and a control signal generating circuit (810) that receives an input control signal (812) from, for example, a keyboard processor or other suitable processor (604) indicating that the device has requested generation of haptic feedback utilizing the piezoelectric actuator (142). The control signal generating circuit (810) provides at least two pulse-with-modulated control signals, one to control the charging circuit and one to control the discharging circuit to produce the unidirectional voltage drive signal, that in one example is a raised cosine drive signal (904).

An output voltage VC obtained by boosting an input voltage VIN by means of a charge pump control circuit 3 of a charge pump 102 is supplied as a power supply voltage to a control circuit 4 of a step-up converter. It is thus possible to eliminate the need for a conventional self-bias method, eliminate switching from startup oscillation to main oscillation of the conventional self-bias method upon startup, and overcome problems caused by the switching of oscillation states, thereby achieving switching power supply circuitry starting in a reliable and stable manner.

A method and apparatus for use in improving linearity sensitivity of MOSFET devices having an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to address degradation in second- and third-order intermodulation harmonic distortion at a desired range of operating voltage in devices employing an accumulated charge sink.

A touch sensor comprising an acoustic wave transmissive medium having a surface; a plurality of acoustic wave path forming systems, each generating a set of incrementally varying paths through said transmissive medium; and a receiver, receiving signals representing said sets of waves, a portion of each set overlapping temporally or physically by propagating in said transmissive medium along axes which are not orthogonal. The waves may also be of differing wave modes. The receiver system may include a phase, waveform or amplitude sensitive system. Reflective arrays are associated with said medium situated along a path, said path not being a linear segment parallel to a coordinate axis of a substrate in a Cartesian space, a segment parallel to an axial axis or perpendicular to a radial axis of a substrate in a cylindrical space, nor parallel and adjacent to a side of a rectangular region of a small solid angle section of a sphere; situated along a path substantially not corresponding to a desired coordinate axis of a touch position output signal; situated along a path substantially non-parallel to an edge of said medium; has a spacing of elements in said array which differs, over at least one portion thereof, from an integral multiple of a wavelength of an incident acoustic wave; has elements in said array which are non-parallel; has an angle of acceptance of acoustic waves which varies over regions of said array; and / or coherently scatter at least two distinguishable acoustic waves which are received by said receiving system.

A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.