Abstract:
This invention includes a square wave signal generating circuit 20 for generating a square wave signal whose frequency changes; a MOS transistor 12 which is turned on/off on the basis of the square wave signal to supply a driving current to a vibrator 14; and a frequency shift detecting circuit 24 for detecting a frequency shift between the square wave signal from the square wave generating circuit and a resonance frequency of the vibrator. The shift in the frequency generated by the square wave generating circuit is trimmed by a signal detected by the frequency shift detecting circuit.
Abstract:
This invention realizes an incoming call notification operation for portable equipments in which the amplitude of vibration matches the rhythm of the melody, by electrically connecting an electromagnetic induction actuator that produces melody and vibration to an integrated circuit that outputs the melody generation signal and the vibration signal, and by applying to the electromagnetic induction actuator either the melody generation signal from the integrated circuit or a signal created by mixing the melody generation signal and the vibration generation signal.
Abstract:
An apparatus levitates and transports an object. The apparatus levitates the object above the surfaces of a plurality of vibrators by air pressure of sound waves that are generated by the vibrators. The apparatus has a plurality of vibration devices, each of which corresponds to one of the vibrators. Each vibration device includes a first transducer for vibrating the corresponding vibrator. Each transducer includes a super-magnetostrictive material. A common power source is connected to at least two of the first transducers for actuating the first transducers.
Abstract:
The warning tone transmitter (10) according to the invention has a piezoelectric horn element (12) with two input connectors (29, 30) for the application of the supply voltage at a determined frequency and has a circuit arrangement (14) fed from the current supply, which generates the supply voltage. In order to be able to receive confirmation that the horn signal is actually generated by the warning tone transmitter (10) and in order to be able more easily to calibrate the warning tone transmitter (10) such that it is driven at its resonant frequency the piezoelectric horn element (12) has an additional output connector (34), which, when the horn element (12) is fed with the supply voltage, generates an answering signal taken to the circuit arrangement (14) if the piezoelement is actually oscillating. The magnitude of the answering signal is a value for the sound volume of the warning tone transmitter (10).
Abstract:
A piezoelectric bending transducer includes a support body, a stack of piezo-ceramic layers, arranged thereon and flat electrodes arranged between the layers. On the side of the support body facing the stack, an adaptation layer is arranged with essentially the same coefficient of expansion as the piezo-ceramic. The bending transducer displays a good actuating power and a low thermal natural distortion with economical production costs. The transducer is particularly suitable for application in a valve.
Abstract:
Method, apparatus and computer programs are described for compensating for the effect of temperature on the sensitivity of electrostatic ultrasound (US) transducers, particularly as used in an automotive occupancy sensing (AOS) systems for sensing the nature or type of occupant and the location of the occupant with respect to the vehicle interior. The invention permits the AOS to classify the occupancy state of the vehicle from a US echo signal substantially free of the effects of temperature on signal amplitude. A capacitive divider or voltage monitor is employed to measure the capacitance of the transducer. The voltage monitor output is used by the scaling algorithm of a compensator to determine the scaling factor to be applied to the US transducer signal to compensate for the effect of temperature on the transducer sensitivity. Calibration procedures and software are disclosed for determining the coefficients of the scaling algorithm to compensate for temperature effects and also to compensate for installation factors, transducer manufacturing variations, and circuit board effects. The system disclosed is useful for other types of signal processing in addition to temperature compensation of AOS ultrasonic signals, and may be used in other ranging devices such as cameras, golf or binocular range finders, and measuring devices and instruments.
Abstract:
A screening machine having a base is provided. A screen is coupled to the base to separate material by size. The screening machine includes a vibration motor having piezoelectric elements and a vibration amplifier located between the piezoelectric elements and the screen. One or more of the piezoelectric elements can be used as sensors to provide feedback for operation control.
Abstract:
The invention relates to a piezoelectric bending transducer (1), comprising a support body (3), a stack (4) of piezoceramic layers (6), arranged thereon and flat electrodes (7, 8) arranged between the layers (6). On the side of the support body (3) facing the stack (4) an adaptation layer (10) is arranged with essentially the same coefficient of expansion as the piezoceramic. The bending transducer (1) displays a good actuating power and a low thermal natural distortion with economical production costs. Said transducer is particularly suitable for application in a valve.
Abstract:
The warning tone transmitter (10) according to the invention has a piezoelectric horn element (12) with two input connectors (29, 30) for the application of the supply voltage at a determined frequency and has a circuit arrangement (14) fed from the current supply, which generates the supply voltage. In order to be able to receive confirmation that the horn signal is actually generated by the warning tone transmitter (10) and in order to be able more easily to calibrate the warning tone transmitter (10) such that it is driven at its resonant frequency the piezoelectric horn element (12) has an additional output connector (34), which, when the horn element (12) is fed with the supply voltage, generates an answering signal taken to the circuit arrangement (14) if the piezoelement is actually oscillating. The magnitude of the answering signal is a value for the sound volume of the warning tone transmitter (10).
Abstract:
Method and apparatus for modulating the vibrations of an object with a constant amplitude has a sensor, e.g., a piezoelectric transducer, for sensing the vibrations. A light source, e.g., an LED, receives the sensed signal and illuminates a light dependent resistor (LED) In turn, a control circuit controls the vibration amplitude in accordance with the LDR resistance. A full wave bridge rectifier can be used between the sensor and the LED.