Marko Rodin Coil -- 007 Device

[minnie]

      How about this?
   A book, "The New Physics" authors T.Webby & B.Tinman.
           John.

[picowatt]

John,,

I play in the mechanical world and a constant force on and off is a square wave,, perfect and simple and true.

Besides John,, there are no such things as "ideal",, I thought you understood that.

Even in the mechanical world, the concept of the frequency content of a waveform versus its repetition rate is important.

If you were going to make a 1Hz mechanical square wave with a 50% duty cycle and a rise and fall time of .01 seconds, using a solenoid, you would need the solenoid's actuator to travel in or out in just .01 seconds.  That is much faster than the .5 seconds on and .5 seconds off of the 1Hz square wave being produced.  A sine wave that rises to its peak in .01 seconds would have a frequency of 25hz (.01 seconds to its positive peak, .01 seconds back to zero, .01 seconds to its negative peak, and .01 seconds back to zero which is .04 seconds total, or 25 Hz).  Simply stated, the 1Hz square wave created by the solenoid moving in and out as described would need to have a harmonic content that extended to at least the 25Hz necessary to produce the .01 second rise and fall time.

The squareness of the "edge", that is, the rise and fall portion of the square wave, requires a much faster rate (frequency) than the 1Hz square wave being produced.  To say that the square wave is 1Hz only implies that one full on/off cycle happens once every second but its frequency content is much higher.  If the square wave were just a pure sine wave, the frequency content would also be 1Hz.  But the 1Hz square wave contains much faster moving components (the rising and falling edges) that are created using rates (frequencies) much faster than the .5 seconds of on and off time.   

If you stood next to a very loud machine that was generating a square/rectangular wave, you would probably want to use hearing protection.  While wearing the hearing protection, you would still hear the machine, but it would sound muffled.  Instead of "bang, bang, bang", you hear "thump, thump, thump".  The hearing protection is attenuating the high frequencies (harmonics) contained in the square/rectangular wave generated by the machine.

A carpenter using a hammer hitting a nail every 2 seconds is generating a .5 Hz waveform but the sound of the impact of the hammer against the nail is a sharp "bang" sound containing many high frequencies.  Although the carpenter is creating a .5Hz waveform (the rate he is hammering) the frequencies contained in that waveform are much higher.  Again, hearing protection can attenuate the higher frequencies and reduce the loud bang sound to a duller thud.

A car's muffler is another example.  Instead of the loud "bang" sound produced by an engine without a muffler, the muffler attenuates the high frequency content reducing the the exhaust sound to a rumble.  That rumble is the fundamental and lower frequency content of the engine's exhaust sound with the higher frequencies attenuated by the muffler.  The repetition rate, that is, the frequency at which the engine fires, remains the same, but the muffler attenuates the higher frequencies contained in the waveform produced as the exhaust valves open.

The point is that even though a waveform may repeat at a given rate (have a certain repetition "frequency"), the frequency content of that waveform can be vastly different.  A square wave, for example, contains a fundamental frequency (sine wave) equal to its repetition rate and a bunch of higher frequency odd harmonics (more sine waves) necessary to produce the faster square edges.

All waveshapes, regardless of their complexity, can be disassembled into the individual frequencies (sine waves) contained in and necessary to make that waveshape.

PW     

[tinman]

      How about this?
   A book, "The New Physics" authors T.Webby & B.Tinman.
           John.

Or overunity farm animals-by minnie.

Brad

[tinman]

No, using the same set of criteria, there is no such thing as a perfect square wave in the mechanical world either.

MH the mechanic is at it again.

Are you sure minneme isnt your son?.


Brad

[tinman]

Webby,
          I just don't think you're getting it.
An "ideal" square wave isn't achievable in practice.
        John.

As long as there are no vibrations,an ideal square wave is achievable.


Brad