I need to make a standing wave generator...Any simple ideas?

[Ziggy]

I need a standing wave generator to produce standing waves at audio frequencies inputed. It may be simple but the answer eludes me...The inputs will be from two freq. generated sine waves. I just need to produce the same signal but in opposite directions and output it to a linear amp.
thanks for any help...
Ziggy

 

[audioguru]

Standing waves are produced by resonances and reflections in a room. You might be able to make a standing wave with a single frequency and an adjustable phase shift.

A Leslie speaker rotated to make standing waves because in those days they did not know how to produce an adjustable phase shift.

 

[crutschow]

Standing waves are produced by resonances and reflections in a room. You might be able to make a standing wave with a single frequency and an adjustable phase shift.

A Leslie speaker rotated to make standing waves because in those days they did not know how to produce an adjustable phase shift.

A standing wave in a room can be generated by selecting the proper frequency based upon the rooms size and shape. It requires no phase shift change.

A Leslie speaker is used to provide a certain type of tremolo or vibrato affect (which apparently can be simulated by certain types of phase shifting of the audio signal). It's not particularly related to standing waves in a room

 

[audioguru]

In a PM to me, the OP says that he wants to explode a virus (a medical one) by tuning a standing wave inside a plazma tube to the resonant frequency of the virus.
Why do people believe the lies that quack "doctors" talk about?

 

[Blueteeth]

In a PM to me, the OP says that he wants to explode a virus (a medical one) by tuning a standing wave inside a plazma tube to the resonant frequency of the virus.
Why do people believe the lies that quack "doctors" talk about?

I understand your frustration with the subject, and although this forum isn't really the place to discuss the validity of so called 'pseudo-science' it bugs (see what I did there?) me too. However, regardless of the OP's intentions, providing its not hazardous and providing infomation isn't responsible for harm/crime, I don't see why we can't just provide answers.

Wehther you're producing a standing wave in liquid, or gas, either way its a fluid. Open ends of tubes reflect longitudinal waves as is often used in musical instruments, with air to resonate at a particular frequency. A typical setup would be a wide range frequency transducer (a 'speaker' for audio) at the end of a tube/cavity of a specific length. To create a standing wave, you must set the length of the tube, as well as the frequency of sound (above, below, or at audio frequencies) to resonate.

YouTube - Standing waves in water in a speaker cone
Standing Waves and Musical Instruments

A great link:
A New Wave: Scientists Write on Water | LiveScience

Simply providing a sound source (longitudinal waves) of a particular frequency doesn't create a standing wave, it all depends on the medium used, and the shape of the cavity the medium is in. In other words, in ain't easy. For 'zapping viruses', in a controlled situaiton I don't see why it wouldn't kill them, but the frequencies would be high, and it'll be impractical in any other situation. Plus, plenty of other things kill viruses, UV, RF, electricity

 

[Ziggy]

Thanks, for the information, very cool videos...

I must clarify that I need to take 2 identical sine outputs from a signal generator but in opposite directions..take that output which will be a standing wave and modulate it and send it to a RF amp and output it to a "tube" antenna.

Could this mixing of the two signals be acomplished by transistors, OP amps, comparators or some circuitry to output it for modulation.

Thanks, guys I understand that this may take some thought..at least for me..and standing waves are not desireable in any application especially with RF and Audio..That being said propably noone has intentionally tried to create them ..

BTW, Doctors do not want this kind of thing to work! They would not be able to sell drugs...Resonance was initiated by Tesla and to the best of my knowlege he was not a "Quack" and was able to bring down buildings, create earthquakes, and send electricty through the air...we owe even our simplest electronic knowlege to him!
Thanks for any information you may share...
Ziggy

 

[Nigel Goodwin]

BTW, Doctors do not want this kind of thing to work! They would not be able to sell drugs...Resonance was initiated by Tesla and to the best of my knowlege he was not a "Quack" and was able to bring down buildings, create earthquakes, and send electricty through the air...we owe even our simplest electronic knowlege to him!

Tesla was very much a quack, he did a few great things, and lots of complete rubbish

Much like most scientists really?.