Abstract:
The method of controlling a linear vibration welding apparatus, in accordance with the invention, may comprise the steps of: fastening a first workpiece portion in a fixed position; fastening a second workpiece portion to a reciprocating member; energizing a first single winding magnet with direct current power to create a magnetic field; sensing a location of the reciprocating member with respect to a zero point; and energizing a second magnet when the reciprocating member has crossed the zero point when moving towards the first magnet. The linear vibration welding apparatus in accordance with the invention may comprise: a frame; a flexure array; a first magnet assembly; a second magnet assembly; a digital controller; and direct current amplifiers for powering the magnet assemblies.
Abstract:
A vibration-generating device that operates always following up the mechanical resonance point is disclosed. A vibration-generating device (1) is constituted by a vibration-generating unit (2) that comprises a magnet (11) and an electromagnetic coil (13) both fixed floatingly by a spring member (12), and the electromagnetic coil (13) is driven by a square-wave to generate vibrating power. The vibration-generating device (1) has a drive control unit (10) that monitors the driving voltage of the electromagnetic coil (13) at regular time intervals, increases the driving frequency of the electromagnetic coil (13) when the induced voltage waveform of the driving voltage increases with time and decreases the driving frequency of the electromagnetic coil (13) when the induced voltage waveform decreases with time. As a result, since the driving frequency of the electromagnetic coil (13) can be changed to the resonance frequency of the vibration-generating unit (2), the driving of the electromagnetic coil can always follow up the mechanical resonance point, and a large vibrating power can be obtained.
Abstract:
A drive for driving a vibration source comprises a sound source (10) for generating tone signals, a DC motor (24) as a vibration source, a low-pass filter (LPF) (16) for extracting low-frequency components from tone signals output from the sound source (10), a detector circuit (18) for detecting the output signal from the low-pass filter (16), a rectifier circuit (20) for rectifying the output from the detector circuit (18), and an amplifier (22) for driving the vibration source based on the low-frequency components extracted by the low-pass filter (16).
Abstract:
A sounder has a drive coil (40) which receives a varying drive signal from a drive circuit. The magnetic field resulting therefrom drives an armature (12) which is mounted on a diaphragm (10) which produces sound due to the vibration thereof. A second coil (42) is magnetically and electrically connected to the drive coil (40). A diode (D1) is connected in series with the second coil and is arranged such that no current flows in the second coil (42) when the drive signal (which is unipolar) generates a current in the drive coil (40). When the drive signal is cut off, a current flows in the second coil (42) and charge is stored in a capacitor C1. The energy thus stored may be used to power the drive circuit. In this way, the power used by the sounder corresponds to the losses in the circuit and due to the acoustic power radiated by the sounder. Since this is only a small proportion of the power needed to drive the drive coil (40), the sounder is efficient.
Abstract:
Provided is a broadband and large displacement angular vibrator, comprising an outer housing, a vibration table (B-1), a main spindle (B-2), a moving coil assembly, a magnetic circuit assembly, a holding brake assembly, a motor and closed loop control assembly thereof, an electic viscoelastic feedback control assembly, an air bearing, and an angular displacement sensor; the moving coil comprises a moving coil substrate (B-3) and a coil(B-4); the moving coil substrate (B-3) is fixed to the main spindle (B-2); the magnetic circuit assembly comprises a magnetic ring (E-1), a central magnetic pole e(E-2), and magnets (E-3); the magnetic ring (E-1), central magnetic pole (E-2), magnets (E-3), and air gap form a closed magnetic circuit; the central magnetic pole (E-2) is located inside the magnetic ring (E-1), the magnets (E-3) is located between the magnetic ring (E-1), the magnets (E-3) is located between the magnetic ring (E-1) and the central magnetic pole (E-2), and the magnets (E-3) is attached to the central magnetic pole (E-2); the outer housing has the holding brake assembly; the holding brake assembly comprises a brake lining (D-8), an oil distribution sleeve (D-7), and an oil reservoir having a piston (D-5); the brake lining (D-8) and the oil distribution sleeve (D-7) enclose a hydraulic oil chamber; when the hydraulic oil is pressed into the hydraulic oil chamber from the oil reservoir, the magnetic circuit assembly brakes; when the hydraulic oil flows back to the oil reservoir, the magnetic circuit assembly rotates with the motor rotor. The present angular shaker has the advantage of being able to switch between intermediate-frequency and low-frequency, and has small output waveform distortion.
Abstract:
A mobile terminal with an electromagnetic actuator for generating speech, buzzing sound, or low-frequency vibration. The mobile terminal generates little abnormal sound. In this electromagnetic actuator, the terminal lugs are short-circuited, the terminal lugs are electrically connected to amplifiers, or an amplifier is electrically connected to a signal generator for generating a constant-voltage signal or a constant-frequency signal. In such a way, the abnormal sound caused by the vibration of a mechanical vibration system of the actuator is reduced.
Abstract:
The invention relates to a signal horn upon which external influences have an effect which is as minor as possible. The inventive signal horn comprises a control circuit for adaptively modifying an operating variable in order to bring it into line with a predefinable set-point value. A switch (6);controlled by a pulse generator (6); is used to control an excitation current (I) flowing through the signal horn in relation to the pulse frequency and/or pulse-scan ratio. Switching means (11) which detect one or several characteristic variables of the excitation current (I) are provided, in addition to other switching means (12) which provide one or several manipulated variables for the pulse generator (6) from the deviation between the characteristic variable(s) derived from the excitation current (I) and one or several set-point values.
Abstract:
A circuit of the present invention is a driving circuit for driving a vibrator having a mechanical vibration system which resonates at a resonance frequency. The driving circuit outputs to the vibrator at least two signals of different frequencies which are included in a frequency range including the resonance frequency. The vibrator has a function of converting an electric signal into at least one of a sound and a vibration.
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:
There is provided a vibration generator that permits to operate by following a mechanical resonance point. The vibration generator 1 has a vibration generation portion 2 having an electromagnetic coil 13 and a magnet 11 float-fixed by a spring member 12. The electromagnetic coil 13 is square-wave driven to obtain vibration force. The vibration generator 1 comprises a driving control portion 10 for detecting a driving voltage of the electromagnetic coil 13 at a predetermined constant interval. By the driving control portion 10, a driving frequency of the electromagnetic coil 13 is made high when an induced voltage waveform of the driving voltage is of rightward increase type, and the driving frequency is made low when the induced voltage waveform is of leftward increase. This permits the driving frequency of the electromagnetic coil to be shifted to a resonance frequency of the vibration generation portion 2. Consequently, driving of the electromagnetic coil 13 can follow a mechanical resonance point so that an sufficiently large vibration can be obtained.