Why is resonance bad

This is important, especially in RF circuits, and in other areas too. Alfred Centauri Alfred Centauri Parallel circuits you get maximum impedance. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown.

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Question feed. Accept all cookies Customize settings. It is as powerful when applied to the earth as it is when applied to a [violin note shattering a] wineglass, a [boy pushing a man on a] swing, or a steel link.

Anyone who doubts should only bear in mind the illustration of the swing. A small boy, by each time adding a pound to the force with which a pound man swings, can soon set the man swinging with the force of pounds. It is necessary only to keep adding a little force at the right time.

Every object depending on its mass and stiffness when excited vibrates at its natural frequency. Watches, musical instruments, microwave ovens, mobile phones and many other devices in our day-to-day life make use of this phenomenon. However, there is an undesirable side to these vibrations that can lead to the failure of structures and components. This failure mode, resonance failures, is equally applicable to large structures and small machine parts alike.

Not only bridges, towers and skyscrapers, but also blades, bearings, piping and fasteners can fail due to resonance. Air and gas vapor columns can also resonate at their natural frequencies, in the same way that percussion instruments work, and this can lead to failures.

Large towers and buildings swaying during an earthquake can fail if the swaying coincides with the natural frequency of the structure. Architects consider this while designing these buildings. The Taipei , one the tallest building in the world, has a Ton pendulum acting as mass damper to cancel any resonance.

The failure in most cases is not because of very high stress on the component but because of continuous reversal of stress at a nodal point.

The antiresonance can be described as the frequency where the direct piezo effect is creating current at an opposite phase to the intrinsic capacitance of the transducer. That means mechanically generated current is canceling with capacitive current, thus making the current draw of the transducer very small giving it a high impedance.

Actually, if you were to hold voltage amplitude at a precise level, you would not find any distinguishing feature from a displacement vs frequency response at the antiresonance frequency. If the displacement is smaller at anti-resonance in comparison to the resonance frequency, why would we use anti-resonance at all?

Most commonly, ultrasonic welding equipment uses anti-resonance, so why should those applications use antiresonance if it takes more voltage to drive the transducer to the desired mechanical output. The assumption is that high voltage is not desirable. But why is it a good thing?

What benefits does antiresonance driving provide? Antiresonance presents a high electrical impedance to the electrical driver. When a transducer is loaded, the antiresonance impedance drops —voltage delivered to the piezo is still constant because the impedance is still high although lower than before the amount of power delivered increases. What is happening is that the transducer output power is self-regulating without the need for a high-performance feedback circuit. When the transducer is loaded, more power is instantaneously required to maintain the oscillation amplitude -hence, using the anti-resonance frequency drive promotes an analog method of adjusting power according to the load presented to the transducer.

Antiresonance drive can also be thought of as oscillation amplitude correlating directly with voltage, whereas at resonance the oscillation amplitude correlates to current. Because electrical driving circuits operate on a controlled output voltage level scheme, and not constant current, utilizing antiresonance makes the electronics and control algorithm simpler. A proper transformer is all you need to efficiently step up your low voltage driver to become an antiresonance driver.

If your application requires a lightweight electrical driver, this method may not be possible because transformers are large in comparison to other electronic components.