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Air core transformer question -- help

Started by Unknown January 5, 2016
On Thursday, January 7, 2016 at 10:00:07 AM UTC-5, legg wrote:
> On Mon, 4 Jan 2016 20:36:18 -0800 (PST), dakupoto@gmail.com wrote: > > > >I replaced the transformer with an air core > >transformer, obtained by carefully removing > >the iron core of the transformer used above, > >The winding is completely intact, tested by > >measuring the winding resistance of both > >the primary and secondary, with the transformer > >not connected. I am fully aware of the reluctance > >issues but this time the transformer output > >is just about 0.5 Volts - 1.0 Volts AC. So > >what is going wrong ? All hints/suggestions > >are welcome. Thanks in advance for your help. > > For your own benefit, instead of removing the core, > you might instead reconfigure it so that an adjustible gap is > possible. > > EI stampings can be grouped with 'all E' and 'all I' groupings. > > Gradually increasing the gap in paper-width-thick increments will show > you what's happening as you change the effective permeability of the > magnetic core from the initially high value of silicon steel, to that > of free space. ( uo = 4 x pi x E-7 ) > > RL
Thanks to each of for your helpful comments. Initially, the astable multivibrator that I am using to excite the bifilar winding had an oscillation frequency of approx. 5.5 KHz (as estimated from o'scope traces), but now, after some modifications, the oscillation frequency has been boosted to 100 KHz. Now the output is 8 Volts AC, across the primary of the air core transformer, and that is sufficient for my initial proof of concept design.
On Friday, January 8, 2016 at 12:22:43 AM UTC-5, daku...@gmail.com wrote:
> On Thursday, January 7, 2016 at 10:00:07 AM UTC-5, legg wrote: > > On Mon, 4 Jan 2016 20:36:18 -0800 (PST), dakupoto@gmail.com wrote: > > > > > > >I replaced the transformer with an air core > > >transformer, obtained by carefully removing > > >the iron core of the transformer used above, > > >The winding is completely intact, tested by > > >measuring the winding resistance of both > > >the primary and secondary, with the transformer > > >not connected. I am fully aware of the reluctance > > >issues but this time the transformer output > > >is just about 0.5 Volts - 1.0 Volts AC. So > > >what is going wrong ? All hints/suggestions > > >are welcome. Thanks in advance for your help. > > > > For your own benefit, instead of removing the core, > > you might instead reconfigure it so that an adjustible gap is > > possible. > > > > EI stampings can be grouped with 'all E' and 'all I' groupings. > > > > Gradually increasing the gap in paper-width-thick increments will show > > you what's happening as you change the effective permeability of the > > magnetic core from the initially high value of silicon steel, to that > > of free space. ( uo = 4 x pi x E-7 ) > > > > RL > > Thanks to each of for your helpful comments. Initially, the astable multivibrator that I > am using to excite the bifilar winding had > an oscillation frequency of approx. 5.5 KHz > (as estimated from o'scope traces), but now, after some modifications, the oscillation frequency has been boosted to 100 KHz. Now > the output is 8 Volts AC, across the primary > of the air core transformer, and that is > sufficient for my initial proof of concept design.
If you want a higher frequency transformer there are all sorts of ferrite cores that you could maybe use. Is there a lot of power involved? George H.
On 1/7/2016 9:03 AM, DecadentLinuxUserNumeroUno wrote:
> On Thu, 07 Jan 2016 09:58:04 -0500, legg <legg@nospam.magma.ca> Gave us: > >> On Mon, 4 Jan 2016 20:36:18 -0800 (PST), dakupoto@gmail.com wrote: >> >> >>> I replaced the transformer with an air core >>> transformer, obtained by carefully removing >>> the iron core of the transformer used above, >>> The winding is completely intact, tested by >>> measuring the winding resistance of both >>> the primary and secondary, with the transformer >>> not connected. I am fully aware of the reluctance >>> issues but this time the transformer output >>> is just about 0.5 Volts - 1.0 Volts AC. So >>> what is going wrong ? All hints/suggestions >>> are welcome. Thanks in advance for your help. >> >> For your own benefit, instead of removing the core, >> you might instead reconfigure it so that an adjustible gap is >> possible. >> >> EI stampings can be grouped with 'all E' and 'all I' groupings. >> >> Gradually increasing the gap in paper-width-thick increments will show >> you what's happening as you change the effective permeability of the >> magnetic core from the initially high value of silicon steel, to that >> of free space. ( uo = 4 x pi x E-7 ) >> >> RL > > Can we really ever put a price on space? >
Of course. Just ask NASA.
On Sun, 10 Jan 2016 04:53:23 -0600, John S <Sophi.2@invalid.org> Gave
us:

>On 1/7/2016 9:03 AM, DecadentLinuxUserNumeroUno wrote: >> On Thu, 07 Jan 2016 09:58:04 -0500, legg <legg@nospam.magma.ca> Gave us: >> >>> On Mon, 4 Jan 2016 20:36:18 -0800 (PST), dakupoto@gmail.com wrote: >>> >>> >>>> I replaced the transformer with an air core >>>> transformer, obtained by carefully removing >>>> the iron core of the transformer used above, >>>> The winding is completely intact, tested by >>>> measuring the winding resistance of both >>>> the primary and secondary, with the transformer >>>> not connected. I am fully aware of the reluctance >>>> issues but this time the transformer output >>>> is just about 0.5 Volts - 1.0 Volts AC. So >>>> what is going wrong ? All hints/suggestions >>>> are welcome. Thanks in advance for your help. >>> >>> For your own benefit, instead of removing the core, >>> you might instead reconfigure it so that an adjustible gap is >>> possible. >>> >>> EI stampings can be grouped with 'all E' and 'all I' groupings. >>> >>> Gradually increasing the gap in paper-width-thick increments will show >>> you what's happening as you change the effective permeability of the >>> magnetic core from the initially high value of silicon steel, to that >>> of free space. ( uo = 4 x pi x E-7 ) >>> >>> RL >> >> Can we really ever put a price on space? >> > >Of course. Just ask NASA.
I DLd a pic of part of the hifi IPAC probe the other day. I used to make some pretty elaborate and refined SMA runs in some of my rack gear, but these guys are deep into it! http://www.mpifr-bonn.mpg.de/776874/zoom.jpg
>> &#2013266080; &#2013266080;Can we really ever put a price on space? >
>Of course. Just ask NASA.
I'm running a promotion this week--prime unoccupied volume a stone's throw from sunny Pluto. Only $1 per thousand cubic feet. Serious enquiries only. Cheers Phil Hobbs
On Sun, 10 Jan 2016 05:11:40 -0800 (PST), Phil Hobbs
<pcdhobbs@gmail.com> Gave us:

>>> &#2013266080; &#2013266080;Can we really ever put a price on space? >> > >>Of course. Just ask NASA. > >I'm running a promotion this week--prime unoccupied volume a stone's throw from sunny Pluto. Only $1 per thousand cubic feet. > >Serious enquiries only. > >Cheers > >Phil Hobbs
Only interested if you can offer one day transit times..
On 01/10/2016 08:44 AM, DecadentLinuxUserNumeroUno wrote:
> On Sun, 10 Jan 2016 05:11:40 -0800 (PST), Phil Hobbs > <pcdhobbs@gmail.com> Gave us: > >>>> Can we really ever put a price on space? >>> >> >>> Of course. Just ask NASA. >> >> I'm running a promotion this week--prime unoccupied volume a stone's throw from sunny Pluto. Only $1 per thousand cubic feet. >> >> Serious enquiries only. >> >> Cheers >> >> Phil Hobbs > > > Only interested if you can offer one day transit times.. >
With a 1 cubic mile purchase, I'll Fedex you the deed (quitclaim of course). A super deal at only $147,197,952. Cheers Phil Hobbs -- 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 hobbs at electrooptical dot net http://electrooptical.net
On Sun, 10 Jan 2016 04:53:23 -0600, John S <Sophi.2@invalid.org>
wrote:

>On 1/7/2016 9:03 AM, DecadentLinuxUserNumeroUno wrote: >> On Thu, 07 Jan 2016 09:58:04 -0500, legg <legg@nospam.magma.ca> Gave us: >> >>> On Mon, 4 Jan 2016 20:36:18 -0800 (PST), dakupoto@gmail.com wrote: >>> >>> >>>> I replaced the transformer with an air core >>>> transformer, obtained by carefully removing >>>> the iron core of the transformer used above, >>>> The winding is completely intact, tested by >>>> measuring the winding resistance of both >>>> the primary and secondary, with the transformer >>>> not connected. I am fully aware of the reluctance >>>> issues but this time the transformer output >>>> is just about 0.5 Volts - 1.0 Volts AC. So >>>> what is going wrong ? All hints/suggestions >>>> are welcome. Thanks in advance for your help. >>> >>> For your own benefit, instead of removing the core, >>> you might instead reconfigure it so that an adjustible gap is >>> possible. >>> >>> EI stampings can be grouped with 'all E' and 'all I' groupings. >>> >>> Gradually increasing the gap in paper-width-thick increments will show >>> you what's happening as you change the effective permeability of the >>> magnetic core from the initially high value of silicon steel, to that >>> of free space. ( uo = 4 x pi x E-7 ) >>> >>> RL >> >> Can we really ever put a price on space? >> > >Of course. Just ask NASA.
Nah, they're an infinite money sink.
On Tuesday, January 5, 2016 at 5:36:22 PM UTC+13, daku...@gmail.com wrote:
> Could some electronics guru please provide > some hints/suggestions to the following ? > First, I built a simple DC->AC push-pull > inverter with a 12 Volt 7AH sealed lead > acid cell battery. The output transformer > is a 120 Volt(primary) and 6-0-6 1.5 Amp > (max) secondary. This configuration worked > fine, and a 60 Watt incandescent lamp > connected to the transformer output terminals > provided steady light. > > I replaced the transformer with an air core > transformer, obtained by carefully removing > the iron core of the transformer used above, > The winding is completely intact, tested by > measuring the winding resistance of both > the primary and secondary, with the transformer > not connected. I am fully aware of the reluctance > issues but this time the transformer output > is just about 0.5 Volts - 1.0 Volts AC. So > what is going wrong ? All hints/suggestions > are welcome. Thanks in advance for your help.
Faradays law - Voltage induced = N X rate of change of flux. No flux is reaching the secondary!
On Sun, 10 Jan 2016 09:37:03 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> Gave us:

>On 01/10/2016 08:44 AM, DecadentLinuxUserNumeroUno wrote: >> On Sun, 10 Jan 2016 05:11:40 -0800 (PST), Phil Hobbs >> <pcdhobbs@gmail.com> Gave us: >> >>>>> Can we really ever put a price on space? >>>> >>> >>>> Of course. Just ask NASA. >>> >>> I'm running a promotion this week--prime unoccupied volume a stone's throw from sunny Pluto. Only $1 per thousand cubic feet. >>> >>> Serious enquiries only. >>> >>> Cheers >>> >>> Phil Hobbs >> >> >> Only interested if you can offer one day transit times.. >> > >With a 1 cubic mile purchase, I'll Fedex you the deed (quitclaim of >course). A super deal at only $147,197,952. > >Cheers > >Phil Hobbs
I'll come close the deal right after I claim my power ball jackpot of 1.6 Billion dollars (which is what it will be by the next drawing date).