摘要:
A piezoelectric transformer (200) with voltage feedback is disclosed. The transformer comprises a piezoelectric plate of predetermined length (L), width (W) and height (H) with a driving section (202) having alternatingly stacked plurality of piezoelectric ceramic layers having internal interdigitated layers. A driven section (206) including an unpolarized dielectric section (208), a voltage feedback section (220) in the form of a multilayer electrode structure or an outer strip, and a normally unpolarized dielectric section (222) is also disclosed. The transformer generates an output voltage at an output terminal by the piezoelectric vibration transmitted from the driving section. A feedback control circuit is connected to the voltage feedback section. The isolated voltage feedback provides feedback control to keep the transformer operating at the proper resonant frequency even if there is a change in output load of the transformer.
摘要:
A method of forming metallization patterns on a block of dielectric material wherein the entire surface area of the dielectric block is encased with a conductive material and unwanted conductive metal is ablatively etched from a designated surface area of the dielectric block to form desired metallized circuit patterns. The invention also comprises a filter and a duplexer formed by the method of the present invention.
摘要:
A pressure sensor for sensing a pressure level of a pressurized medium has, in one embodiment, a high pressure side and a low pressure side. An aperture may extend through at least a portion of the sensor assembly, and a seal is located in the aperture. The seal seals the high pressure side from the low pressure side. Electrical leads extend through the seal between the high pressure side and the. low pressure side. A substrate is located on the high pressure side. A pressure sensitive resistor is mounted on the substrate such that the resistor is directly exposed to the pressurized medium. The resistor changes resistance in response to a change in pressure. The resistor is connected to the electrical leads.
摘要:
A pressure sensor for sensing a pressure level of a medium. The pressure sensor includes a rigid substrate having a medium contacting side and a pressure sensitive resistor mounted on the medium contacting side. The resistor exhibits a change in resistance in response to pressure changes on the resistor above a predetermined threshold. Other embodiments of the invention are shown using a Wheatstone bridge with pressure sensitive resistors and resistors that are insensitive to pressure changes.
摘要:
A crystal electrode that reduces coupled mode noise. A crystal blank has a top surface and a bottom surface. A first electrode is located on the top surface. The first electrode has a contact portion and a polygonal portion. A second electrode is located on the bottom surface. The second electrode has a contact portion and a polygonal portion. The polygonal portions of the first and second electrodes are arranged such that they oppose each other.
摘要:
A weight sensor (10) for sensing an applied weight. The sensor includes a first (20) and second (22) outer substrate that have a first (20C, 22C) and second (20D, 22D) end and an inner surface (20B, 22B) and an outer surface (20A, 22A). The first and second outer substrates (20, 22) are fixedly attached together. Several strain gauge resistors (50, 52) are located on the outer surfaces of the first and second outer substrates (20A, 22A) to generate an electrical signal in response to the substrate being stressed by the applied weight. The electrical signal changes as a function of the applied weight. The sensor is useful in measuring the weight of a vehicle seat occupant.
摘要:
A hermetic ground pin assembly for making an electrical connection between a hermetically sealed enclosure and an external circuit. A case has an aperture and a plug located within the aperture. A low temperature braze alloy is located between the plug and the case to attach the plug within the aperture. Two different pins are attached to opposite sides of the plug. A high temperature braze alloy attaches one of the pins to the plug and the low temperature braze alloy attaches the other pin to the plug.
摘要:
A hermetic multilayered ceramic semiconductor package for micromachined semiconductor devices. A low temperature co-fired ceramic assembly has a cavity and a top and bottom surface. Several vias extend between the top and bottom surfaces and several solder spheres are located on the top surface and are electrically connected to the vias. A micrornachined semiconductor device abuts the bottom surface and covers the cavity such that a movable portion of the micromachined semiconductor device is unconstrained to move within the cavity. Solder is used to connect the vias to solder bumps on the semiconductor device. A seal ring is located between the micromachined semiconductor device and the ceramic assembly for hermetically sealing the micromachined semiconductor device.
摘要:
An oscillator circuit suppresses unwanted oscillation frequencies and allows oscillation in the selected frequency band. The circuit has less sensitivity to aging of components that cause a shift in operating frequency. The oscillator includes a first and second inverting amplifier that each have an input terminal and an output terminal. A crystal resonator is connected between the input terminal of the first amplifier and the output terminal of the second amplifier. A suppression trap is connected between the first and second amplifier for suppressing oscillation outside the desired range of frequencies. The trap includes a parallel tank circuit that is connected between the output terminal of the first amplifier and the input terminal of the second amplifier. A capacitor is connected between the input terminal of the second amplifier and a ground.