Abstract:
An acoustic signal generator, and a method for generating an acoustic signal are described. The acoustic signal generator has a membrane that can oscillate, a deflection sensor for detecting any deflection of the membrane, an exciter configuration that is coupled to the membrane, and a power semiconductor switch with a load path that is connected to the exciter configuration. The switch has a drive connection. A drive circuit has a first connection connected to the drive connection of the power semiconductor switch and at which a drive signal is available. The drive circuit further has a second connection, to which the deflection sensor is connected.
Abstract:
A circuit for driving an electromagnetic source for generating acoustic waves has a dischargeable high-voltage capacitor with a diode or a diode module connected in parallel therewith.
Abstract:
An acoustic signal generator, and a method for generating an acoustic signal are described. The acoustic signal generator has a membrane that can oscillate, a deflection sensor for detecting any deflection of the membrane, an exciter configuration that is coupled to the membrane, and a power semiconductor switch with a load path that is connected to the exciter configuration. The switch has a drive connection. A drive circuit has a first connection connected to the drive connection of the power semiconductor switch and at which a drive signal is available. The drive circuit further has a second connection, to which the deflection sensor is connected.
Abstract:
A self-protected, low emission electronic device for driving a warning horn includes a coil powered from a battery through a control push-button adapted for operation by a user and included in an electric connection between a terminal of the coil and the battery. The device includes a protective circuit portion connected between the battery and the warning horn. The protective circuit portion includes a bridge structure of power components. At least a pair of the power components are MOS power transistors of which one is driven by a charge pump.
Abstract:
Adjustment of the pulse energizing frequency and duty cycle of a vehicle horn is described. The horn is blown by a test energizing circuit with a varying pulse frequency and the and the frequency at which the horn produces the maximum sound pressure level is taken as the predetermined resonant frequency. Then the horn is blown by the test energizing circuit at the resonant frequency with a varying duty cycle value of duty cycle which produces a predetermined striking force of the plunger against the pole piece is taken as the predetermined impact-producing duty cycle which is used for setting the operating duty cycle of the horn in a manner depending upon the type of the horn. The horn is then blown by its own electronic energizing circuit and the actual pulse frequency thereof is adjusted, preferably by laser trimming of a resistor, to match the resonant frequency. Then the horn is blown by its own energizing circuit at the resonant frequency and the duty cycle is adjusted, preferably by laser trimming, to set the actual duty cycle in a known relation to the predetermined impact-producing duty cycle.
Abstract:
An electric horn having a diaphragm connected to a ferromagnetic plunger is driven by an electromagnetic coil to cause vibrations of the diaphragm at the resonant frequency of the diaphragm and plunger combination. A solid state driver has a timer tuned essentially to the frequency of the diaphragm assembly and controls the driver power output to effect coil energization to drive the diaphragm movement synchronously with the timer frequency. The driver output stage comprises a power MOSFET or a Darlington pair.
Abstract:
An electric horn having a diaphragm connected to a ferromagnetic plunger is driven by an electromagnetic coil to cause vibrations of the diaphragm at the resonant frequency of the diaphragm and plunger combination. A solid state driver has a timer tuned essentially to the frequency of the diaphragm assembly and controls the driver power output to effect coil energization to drive the diaphragm movement synchronously with the timer frequency. The driver output stage comprises a power MOSFET or a Darlington pair.
Abstract:
Method and apparatus for initiating and sustaining oscillations in a system having a free oscillatory period, comprising an oscillating means (preferably including a relaxation oscillator of the resistor-capacitor type) connected to apply a periodic driving force to the system, the oscillating means having an intrinsic period approximately equal to the period of the system, a detector connected to sense operation of the oscillating means and the oscillations, if any, of the system and to detect a phase difference therebetween, and circuitry with an input connected to the detector, the circuitry connected to the oscillating means to be effective to modify the oscillations of the oscillating means so as to maintain the phase difference within predetermined limits.