摘要:
An automatic power control system provides a control signal that regulates the output power of at least one laser diode. Coarse adjustment of the control signal is provided by a first means, preferably a digital variable resistor, while fine adjustment and compensation is provided by a second means, preferably by a digital-to-analog converter that receives an input signal proportional to a sensed control system parameter. The control system includes an operational amplifier having a first input coupled to sense output power, and a second input coupled to a DAC to provide finer resolution control. Memory can store system parameter or system parameter variations that can be coupled to the DAC and/or variable resistor to enhance system stability over ambient variations.
摘要:
A method and apparatus for processing transactions. In particular, the mechanism of the present invention is used for processing information for physical transactions. A data structure is received at a customer data processing system for a physical transaction entered into by the customer. This information is extracted and used to update records or other information in the customer data processing system. Further, a second data structure is sent to a supplier of an item used in the physical transaction. This data structure is used by the supplier to update information maintained by the supplier about the item. After updating the information, the information is analyzed to generate statistics about physical transactions involving the item.
摘要:
A method for manufacturing a multi-layer acoustic transducer with reduced total electrical impedance. The method is based on the bonding of two piezoelectric ceramic layers with confronting metallized surfaces to a thin electrical conductor, then electrically connecting the top and bottom surfaces to form a wrap-around electrode while a center conductor forms a second electrode. The total electrical impedance of a two-layer ceramic stack comprised of piezoelectric layers connected in this manner is one-fourth that of a solid ceramic element of the same size. This provides for better matching of the acoustic stack impedance to that of the electrical cable, increased penetration depth for imaging within the body, and improved acoustic element sensitivity.
摘要:
An ultrasonic transducer device comprising: an ultrasonic transducer array micromachined on a substrate; flexible electrical connections connected to the transducer array; and a body of acoustically attenuative material that supports the substrate and the flexible electrical connections. The acoustic backing material may contain additional features, such as tabs or notches, for use in positioning the transducer on fixtures during manufacturing or positioning the transducer within a housing during final assembly. Tabs or other features that are used only during manufacturing may be subsequently removed from the device. The MUT device itself may also be thinned so as to provide flexibility as desired. The backing material is preferably matched in acoustic impedance to the silicon wafer so as to prevent reflection at the interface of any acoustic energy propagating rearward, i.e., in the direction away from the device front surface. The backing material may also possess a high thermal conductivity to assist in removal of heat from the device.
摘要:
A method for manufacturing a multi-layer acoustic transducer with reduced total electrical impedance. The method is based on the bonding of two piezoelectric ceramic layers with confronting metallized surfaces to a thin electrical conductor, then electrically connecting the top and bottom surfaces to form a wrap-around electrode while a center conductor forms a second electrode. The total electrical impedance of a two-layer ceramic stack comprised of piezoelectric layers connected in this manner is one-fourth that of a solid ceramic element of the same size. This provides for better matching of the acoustic stack impedance to that of the electrical cable, increased penetration depth for imaging within the body, and improved acoustic element sensitivity.
摘要:
A high-density connection of multiple circuit boards having overlapping ends arranged in a stack. The metal traces on the stacked circuit boards are electrically connected by contact of the ends of the traces, which ends may be pads. The stacked circuit boards can be clamped, soldered or bonded together. Multiple circuit boards may be connected to a single circuit board. In one embodiment, double-sided circuit boards are stacked so that a first circuit board connects to a second circuit board through a third circuit board disposed intermediate the first and second circuit boards. The circuit boards may be flexible or rigid.
摘要:
A method and apparatus for processing transactions. In particular, the mechanism of the present invention is used for processing information for physical transactions. A data structure is received at a customer data processing system for a physical transaction entered into by the customer. This information is extracted and used to update records or other information in the customer data processing system. Further, a second data structure is sent to a supplier of an item used in the physical transaction. This data structure is used by the supplier to update information maintained by the supplier about the item. After updating the information, the information is analyzed to generate statistics about physical transactions involving the item.
摘要:
Methods for preparing a multi-layer acoustic transducer with reduced total electrical impedance. The methods are based on the stacking of individual piezoelectric layers with metallized surfaces to form a plate in which the metal layers are electrically connected to form interdigitated electrodes. The total electrical impedance of a multi-layer stack comprised of piezoelectric layers connected in this manner is inversely related to the square of the number of layers in the stack. This provides for better matching of the acoustic stack impedance to that of the electrical cable and improved acoustic element sensitivity.
摘要:
A vertical-axis wind turbine for use with an electrical generator for producing power by converting the energy of wind currents into mechanical rotational energy which is then used to operate the electrical generator. In an embodiment, a rotor is responsive to wind currents by imparting rotation upon a central vertical shaft. Preferably, the rotor is designed with functional curved surfaces for efficient operation.
摘要:
An electronic system (1) having an interconnect structure (30, 45). In one embodiment a system (1) includes a first electronic device (2) with a first plurality of contact pads (15) each having a noble metal (18) formed along a first surface (19), and a second electronic device (3) with a second plurality of contact pads (29) each having a noble metal (18) formed along a first surface (19). The noble metal (18) of one of the contact pads (15) of the first device (2) is bonded to the noble metal (18) of one of the contact pads (29) of the second device (3). In one embodiment of an associated method of forming an interconnect structure (45), a first electronic device (2) is provided with a first plurality of contact pads (15) each having a noble metal (18) along a first surface (19), and a second electronic device (3) is provided with a plurality of contact pads (29) each having a noble metal (18) along a first surface (19). One or more of the contact pads (15) on the first device (2) is aligned with one or more of the contact pads (29) on the second device (3) to form pairs of pads (45) for electrical contact with one another. The first surface (19) of a contact pad (15) of the first device (2) is pressed against the first surface (19) of a contact pad (29) on the second device (3) to make contact between the two first surfaces (19).