How to build simple pulsed EMF device?

[Lapis]

I would like to set up an experiment in order to study the effect of pulsed emf's on plant growth.

 

So I want to build a device that emits a 10 Hz pulsed emf, at a strength of about 1-10 Gauss

 

Any suggestions on how to do this? the simpler the better, considering I'm reasonably intelligent Person On the one hand, on the other hand, I'm not the kind of person who likes to sit around constructing complex circuitry

 

thanks for any input

 

one way I thought of is to get a basic frequency generator and use that to get the 10 Hz frequency And rig up a simple copper coil to attach to the frequency generator. but the problem with that, the output amperage of frequency generators is very low. I would never be able to get Anything close to a EMF Of one gauss from it.

 

So perhaps I can amplify the output of a frequency generator…?

[TonyMcC]

Firstly, you measure emf in volts. I'm wondering if a tens machine would do the job. Its really to limit pain by blocking nerves with various patterns of voltage setting up currents in the nerves. http://en.wikipedia.org/wiki/Transcutaneous_electrical_nerve_stimulation

[Lapis]

Firstly, you measure emf in volts. I'm wondering if a tens machine would do the job. Its really to limit pain by blocking nerves with various patterns of voltage setting up currents in the nerves. http://en.wikipedia....rve_stimulation

 

actually, As I understand it, voltage is a measurement of the electrical potential of a wire with a current running through it.

 

Electromagnetic fields, Which are Created as a result of electric currents, are measured in terms of Tesla units and/or gauss units

 

a tens unit delivers a very weak electrical charge. That's not what I'm after.

 

I'm interested in how electromagnetic fields affect the growth of plants, not how electrical charges affect them

 

if anything I said Here is incorrect, somebody please correct me

Edited December 11, 2011 by Lapis

[Cap'n Refsmmat]

Emf is also a commonly used acronym for "electromotive force," which is measured in volts. That's probably what TonyMcC was thinking of.

 

Could you not connect a signal generator to a small amplifier? You don't need terribly much power.

[Lapis]

Emf is also a commonly used acronym for "electromotive force," which is measured in volts. That's probably what TonyMcC was thinking of.

 

Could you not connect a signal generator to a small amplifier? You don't need terribly much power.

 

Okay then, electromotive force. emf for me has always met electromagnetic field, but I'm not familiar with all of the acronyms and whatnot.

 

Signal generator = function generator = frequency generator? same thing?

 

Yes, it seems that setup would work. But do I need a Specific amplifier to couple with a function generator?

 

also, what do you think the output of the amplifier should be in order to generate a one Gauss EMF with a simple copper coil?

[DrRocket]

actually, As I understand it, voltage is a measurement of the electrical potential of a wire with a current running through it.

 

Electromagnetic fields, Which are Created as a result of electric currents, are measured in terms of Tesla units and/or gauss units

 

a tens unit delivers a very weak electrical charge. That's not what I'm after.

 

I'm interested in how electromagnetic fields affect the growth of plants, not how electrical charges affect them

 

if anything I said Here is incorrect, somebody please correct me

 

Magnetic fields are typically measured in Teslas or Gauss, but electromagnetic fields are typically measured in terms of the electric field component, which is in volts/meter. The magnetic field then is determined by the permitivity of free space.

 

A 10 Hz pulse is nearly a contradiction in terms. What I surmise that you mean is a square wave on which is superimposed a 10 Hz sinusoid. But you have failed to specify the desired pulse width which is the most important parameter or the rise and fall and times required to approximate the square wave, which will determine the actual high-frequency content of the signal.

 

Electromagnetic fields are created by the time variation of currents, which is as important as the amplitude of the current. Amplitude of a true DC current determines a static magnetic field, which could just as well be obtained from a solid magnet. I know of no evidence whatever that there is any biological effect from a static magnetic field or any reason to think that there might be. In any case the field generated will not be uniform so you need to do a considerable amount of work to determine the field levels over the space in which you intend to place your plant or plants.

 

Voltage has nothing whatever to do with the "electric potential of a wire" and in fact that phrase is nonsensical. Voltage is the difference in value of the potential function that determines a static electric field when measured at two points. EMF is the result of a line integral of the electric field over a specified path, and the value will in general depend on the path, since time-varying electric fields are not conservative.

 

I suggest that you take a bit of time to learn the basics of electromagnetic theory and to figure out what biological phenomena you are really interested in studying. Any freshman physics text should help with the electromagnetics, Halliday and Resnick's book is one that would suffice. But more importantly you need to figure out what it is that interests you from the biological perspective. An experiment conceived in confusion and ignorance is doomed.

[Lapis]

A 10 Hz pulse is nearly a contradiction in terms.

 

 

really? so you are saying that "an electromagnetic field that pulses at a frequency of 10 Hz" is a phrase that makes no sense?

 

it seems pretty straightforward and simple to me. But hey I could be wrong

 

I know of no evidence whatever that there is any biological effect from a static magnetic field or any reason to think that there might be.

 

 

actually, the effect of pulsed electromagnetic fields on the human body is quite astonishing. It's being used to treat everything from Parkinson's to ALS to schizophrenia to alcoholism

 

http://www.aetna.com...0_499/0469.html

 

http://scholar.google.com/scholar?q=Pulsed+electromagnetic+therapy&hl=en&as_sdt=0&as_vis=1&oi=scholart

 

information on its effect on plants However, is much harder to come by. That's one of the reasons I'm interested in studying it

Edited December 11, 2011 by Lapis

[Externet]

"an electromagnetic field that pulses at a frequency of 10 Hz" is a phrase that makes no sense?

 

If the AM radio station transmitter is turned off and on 10 times each second; you would have about one megahertz pulsed at 10 hertz.

 

If the microwave oven in your kitchen is turned off and on 10 times each second, you would have four and a half gigahertz pulsed at 10 hertz.

 

If the speakers at your home stereo are turned off and on 10 times each second, you would have about 1 kilohertz pulsed at 10 hertz.

 

All the above are then, pulsed at a frequency of 10 Hz. But they are all very different in nature of frequency and the effects they radiate.

 

Your choices of frequencies are near infinite even if you stick only to 10 Hz pulsing. It would be convenient for you to differentiate the concepts before planning your analysis on plants.

 

Try to say 'exposing the plants to a X frequency at a rate of 10 Hertz'

Edited December 11, 2011 by Externet

[DrRocket]

"an electromagnetic field that pulses at a frequency of 10 Hz" is a phrase that makes no sense?

 

If the AM radio station transmitter is turned off and on 10 times each second; you would have about one megahertz pulsed at 10 hertz.

 

If the microwave oven in your kitchen is turned off and on 10 times each second, you would have four and a half gigahertz pulsed at 10 hertz.

 

If the speakers at your home stereo are turned off and on 10 times each second, you would have about 1 kilohertz pulsed at 10 hertz.

 

All the above are then, pulsed at a frequency of 10 Hz. But they are all very different in nature of frequency and the effects they radiate.

 

Your choices of frequencies are near infinite even if you stick only to 10 Hz pulsing. It would be convenient for you to differentiate the concepts before planning your analysis on plants.

 

Try to say 'exposing the plants to a X frequency at a rate of 10 Hertz'

 

You obviously know nothing of either Fourier analysis or sinusoids. Read what I said again, the whole paragraph, and don't make inane comments about fragments.