I want to do an experiment in brainwave entrainment by making a 7 Hz sine wave oscillator out of an XR2206 frequency generator IC and a LM386 amplifier feeding a six inch diameter coil-- which should probably fit around my fat head. ;-) The LM386 has an 8 ohm output, so it shouldn't be hard to find a speaker, if I wanted to use one; but I don't know how to make a good 8 ohm coil to radiate a nice clean undistorted signal-- how many turns, what size wire to use, etc. Does anyone have any suggestions? Ron _____________ "There are special people in this world. We don't ask to be special. We're just born this way. We pass you on the streets every day, unnoticed by most. " -- Cassie Holmes (Push) --

# Designing The Perfect Coil?

Started by ●March 30, 2012

Reply by ●March 30, 20122012-03-30

On Mar 30, 12:14=A0am, Ron Hubbard <or...@dslnorthwest.net> wrote:> I want to do an experiment in brainwave entrainment by making a 7 Hz > sine wave oscillator out of an XR2206 frequency generator IC and a > LM386 amplifier feeding a six inch diameter =A0coil-- which should > probably fit around my fat head. =A0;-) > > The LM386 has an 8 ohm output, so it shouldn't be hard to find a > speaker, if I wanted to use one; but I don't know how to make a good 8 > ohm coil to radiate a nice clean undistorted signal-- how many turns, > what size wire to use, etc. Does anyone have any suggestions? > > Ron > > _____________ > > "There are special people in this world. We don't ask to be special. > We're just born this way. We pass you on the streets every day, > unnoticed by most. " > > -- =A0Cassie Holmes (Push) --Nothing is 'perfect' Ron. But making a coil about right is pretty easy. I start with the coil resistance. You want ~8 ohms so you have that number. You then have to know the size of the B field you want. This (with the current.) gives you the number of turns you need. Then I usually just take a guess at some wire size.. so many turns at some radius to get the total length. Is the resistance of that length of wire the desired 8 ohms? Adjust till it is. George H.

Reply by ●March 31, 20122012-03-31

On Mar 30, 5:24=A0am, George Herold <gher...@teachspin.com> wrote:> On Mar 30, 12:14=A0am, Ron Hubbard <or...@dslnorthwest.net> wrote: > > > > > > > I want to do an experiment in brainwave entrainment by making a 7 Hz > > sine wave oscillator out of an XR2206 frequency generator IC and a > > LM386 amplifier feeding a six inch diameter =A0coil-- which should > > probably fit around my fat head. =A0;-) > > > The LM386 has an 8 ohm output, so it shouldn't be hard to find a > > speaker, if I wanted to use one; but I don't know how to make a good 8 > > ohm coil to radiate a nice clean undistorted signal-- how many turns, > > what size wire to use, etc. Does anyone have any suggestions? > > > Ron > > > _____________ > > > "There are special people in this world. We don't ask to be special. > > We're just born this way. We pass you on the streets every day, > > unnoticed by most. " > > > -- =A0Cassie Holmes (Push) -- > > Nothing is 'perfect' Ron. =A0But making a coil about right is pretty > easy. =A0I start with the coil resistance. =A0You want ~8 ohms so you hav=e> that number. =A0You then have to know the size of the B field you want. > This (with the current.) gives you the number of turns you need. =A0Then > I usually just take a guess at some wire size.. so many turns at some > radius to get the total length. =A0Is the resistance of that length of > wire the desired 8 ohms? =A0Adjust till it is. > > George H.- Hide quoted text - > > - Show quoted text -Uh, probably a silly question but I guess I gotta ask: how would I know the current? Any value I coulld think of now would really be random and meaningless.... Ron ______________ =93Hope for the best, but plan for the worst. =93 =97 Richard Tyler (The 4400) =96=96

Reply by ●March 31, 20122012-03-31

On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote:> > Uh, probably a silly question but I guess I gotta ask: how would I > know the current? Any value I coulld think of now would really be > random and meaningless....OK, so first things first: exactly what sort/intensity of a field are you wishing to create? Bob M.

Reply by ●April 1, 20122012-04-01

On Mar 31, 6:25=A0pm, Bob Myers <bobmyer...@gmail.com> wrote:> On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote: > > > Uh, probably a silly question but I guess I gotta ask: how would I > > know the current? Any value I coulld think of now would really be > > random and meaningless.... > > OK, so first things first: exactly what sort/intensity of a field are you=wishing to create?> > Bob M.I had to take a look at this article again-- http://www.elfis.net/elfol8/e8elfeeg2.htm -- as I am the kind of guy who would rather build something first and worry about the mathematics behind it later (if at all). Trial and error is fun, but sloppy engineering I'm afraid. :-) But it seems like a radiated field of 100 nanoteslas should do the job well, assuming my little project will work at all. Ron

Reply by ●April 1, 20122012-04-01

On Sunday, April 1, 2012 2:42:43 PM UTC-6, Ron Hubbard wrote:> On Mar 31, 6:25=A0pm, Bob Myers <bobmyer...@gmail.com> wrote: > > On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote: > > > > > Uh, probably a silly question but I guess I gotta ask: how would I > > > know the current? Any value I coulld think of now would really be > > > random and meaningless.... > > > > OK, so first things first: exactly what sort/intensity of a field are y=ou wishing to create?> > > > Bob M. >=20 >=20 >=20 > I had to take a look at this article again-- >=20 > http://www.elfis.net/elfol8/e8elfeeg2.htm >=20 > -- as I am the kind of guy who would rather build something first and > worry about the mathematics behind it later (if at all). Trial and > error is fun, but sloppy engineering I'm afraid. :-) >=20 > But it seems like a radiated field of 100 nanoteslas should do the job > well, assuming my little project will work at all. >=20 > RonSo if you know the strength of the field you're trying to produce, and pres= umably this is the field within a loop of wire that is placed around the he= ad, the next place you need to go is: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/curloo.html#c2 Bob M.

Reply by ●April 2, 20122012-04-02

On Mar 31, 7:26=A0pm, Ron Hubbard <or...@dslnorthwest.net> wrote:> On Mar 30, 5:24=A0am, George Herold <gher...@teachspin.com> wrote: > > > > > > > On Mar 30, 12:14=A0am, Ron Hubbard <or...@dslnorthwest.net> wrote: > > > > I want to do an experiment in brainwave entrainment by making a 7 Hz > > > sine wave oscillator out of an XR2206 frequency generator IC and a > > > LM386 amplifier feeding a six inch diameter =A0coil-- which should > > > probably fit around my fat head. =A0;-) > > > > The LM386 has an 8 ohm output, so it shouldn't be hard to find a > > > speaker, if I wanted to use one; but I don't know how to make a good =8> > > ohm coil to radiate a nice clean undistorted signal-- how many turns, > > > what size wire to use, etc. Does anyone have any suggestions? > > > > Ron > > > > _____________ > > > > "There are special people in this world. We don't ask to be special. > > > We're just born this way. We pass you on the streets every day, > > > unnoticed by most. " > > > > -- =A0Cassie Holmes (Push) -- > > > Nothing is 'perfect' Ron. =A0But making a coil about right is pretty > > easy. =A0I start with the coil resistance. =A0You want ~8 ohms so you h=ave> > that number. =A0You then have to know the size of the B field you want. > > This (with the current.) gives you the number of turns you need. =A0The=n> > I usually just take a guess at some wire size.. so many turns at some > > radius to get the total length. =A0Is the resistance of that length of > > wire the desired 8 ohms? =A0Adjust till it is. > > > George H.- Hide quoted text - > > > - Show quoted text - > > Uh, probably a silly question but I guess I gotta ask: how would I > know the current? Any value I coulld think of now would really be > random and meaningless.... > > Ron > > ______________ > > =93Hope for the best, but plan for the worst. =93 > > =A0=97 Richard Tyler (The 4400) =A0=96=96- Hide quoted text - > > - Show quoted text -Well, the current just comes from Ohm's law. If you know the resistance you want, then you've got some amp, with a power supply. That supply sets your maximum current. George H.

Reply by ●April 2, 20122012-04-02

On 04/01/2012 04:42 PM, Ron Hubbard wrote:> On Mar 31, 6:25 pm, Bob Myers<bobmyer...@gmail.com> wrote: >> On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote: >> >>> Uh, probably a silly question but I guess I gotta ask: how would I >>> know the current? Any value I coulld think of now would really be >>> random and meaningless.... >> >> OK, so first things first: exactly what sort/intensity of a field are you wishing to create? >> >> Bob M. > > > > I had to take a look at this article again-- > > http://www.elfis.net/elfol8/e8elfeeg2.htm > > -- as I am the kind of guy who would rather build something first and > worry about the mathematics behind it later (if at all). Trial and > error is fun, but sloppy engineering I'm afraid. :-) > > But it seems like a radiated field of 100 nanoteslas should do the job > well, assuming my little project will work at all. > > Ron > > >Sounds like just the sort of project for someone with a 6-inch diameter head. Maybe make it cone-shaped. ;) Cheers Phil -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net

Reply by ●April 2, 20122012-04-02

Phil Hobbs explained :> On 04/01/2012 04:42 PM, Ron Hubbard wrote: >> On Mar 31, 6:25 pm, Bob Myers<bobmyer...@gmail.com> wrote: >>> On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote: >>> >>>> Uh, probably a silly question but I guess I gotta ask: how would I >>>> know the current? Any value I coulld think of now would really be >>>> random and meaningless.... >>> >>> OK, so first things first: exactly what sort/intensity of a field are you >>> wishing to create? >>> >>> Bob M. >> >> >> >> I had to take a look at this article again-- >> >> http://www.elfis.net/elfol8/e8elfeeg2.htm >> >> -- as I am the kind of guy who would rather build something first and >> worry about the mathematics behind it later (if at all). Trial and >> error is fun, but sloppy engineering I'm afraid. :-) >> >> But it seems like a radiated field of 100 nanoteslas should do the job >> well, assuming my little project will work at all. >> >> Ron >> >> >> > > Sounds like just the sort of project for someone with a 6-inch diameter head. > Maybe make it cone-shaped. ;) > > Cheers > > PhilIs the OP Ron Hubbard related to L Ron Hubbard? :-? -- John G

Reply by ●April 2, 20122012-04-02

On 4/2/2012 3:54 PM, Phil Hobbs wrote:> On 04/01/2012 04:42 PM, Ron Hubbard wrote: >> On Mar 31, 6:25 pm, Bob Myers<bobmyer...@gmail.com> wrote: >>> On Saturday, March 31, 2012 5:26:58 PM UTC-6, Ron Hubbard wrote: >>> >>>> Uh, probably a silly question but I guess I gotta ask: how would I >>>> know the current? Any value I coulld think of now would really be >>>> random and meaningless.... >>> >>> OK, so first things first: exactly what sort/intensity of a field are >>> you wishing to create? >>> >>> Bob M. >> >> >> >> I had to take a look at this article again-- >> >> http://www.elfis.net/elfol8/e8elfeeg2.htm >> >> -- as I am the kind of guy who would rather build something first and >> worry about the mathematics behind it later (if at all). Trial and >> error is fun, but sloppy engineering I'm afraid. :-) >> >> But it seems like a radiated field of 100 nanoteslas should do the job >> well, assuming my little project will work at all. >> >> Ron >> >> >> > > Sounds like just the sort of project for someone with a 6-inch diameter > head. Maybe make it cone-shaped. ;) > > Cheers > > Phil >I was going to suggest he ask for advice when he starts trying to get the 6 in coil of his head. Mikek