AVR-Chat

Hi Ivan,

You didn't say where you are located.  Can you order from Digi-Key?  They 
have a whole assortment of RFID antennas and coils in their catalog.

Zack

On Wed, 21 Sep 2005, Ivan Vernot wrote:

> Hello All,
> Apologies for off topic post but I'm using an AVR for this gadget ;-)
> 
> I  am looking for a supplier that is able to wind an open core coil to be used in an RFID application.
> The coil is used for the antenna of the RFID system and is typically a few tens of turns in reasonable heavy gauge wire (30AWG or so) so that is it relatively self supporting.  
> 
> Does anyone know of a supplier that can supply such coils in <1K qty?
> 
> Kind Regards
> 
> Ivan Vernot
>

Thanks Zack,
After seeing your post I checked Digi-Key.
As far as I can see, they only carry the 'TIRIS' (Texas Instruments RFID) 
stuff.
It is at 132KHz and uses quite large (~1m) antennae.

I am after an antenna <100mm long  (65mm round would be perfect) for use in 
a 125KHz proximity card reader (think of an access control application)

BTW: I am in Sydney Australia.

Thanks for the reply.
Cheers,
Ivan


----- Original Message ----- 

From: "Zack Widup" <w9sz@prairienet.org>
To: <AVR-Chat@yahoogroups.com>
Sent: Wednesday, September 21, 2005 10:25 PM
Subject: Re: [AVR-Chat] OT: Where to get Custom Coils would


>
> Hi Ivan,
>
> You didn't say where you are located.  Can you order from Digi-Key?  They
> have a whole assortment of RFID antennas and coils in their catalog.
>
> Zack
>
> On Wed, 21 Sep 2005, Ivan Vernot wrote:
>
>> Hello All,
>> Apologies for off topic post but I'm using an AVR for this gadget ;-)
>>
>> I  am looking for a supplier that is able to wind an open core coil to be 
>> used in an RFID application.
>> The coil is used for the antenna of the RFID system and is typically a 
>> few tens of turns in reasonable heavy gauge wire (30AWG or so) so that is 
>> it relatively self supporting.
>>
>> Does anyone know of a supplier that can supply such coils in <1K qty?
>>
>> Kind Regards
>>
>> Ivan Vernot
>>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

Make yourself an antenna with a spiral trace on a circuit
board! Resonate it with a capacitor to 125KHz and you
should be in. The more sprirals, you have, the better,
because the resonating cap will be smaller and the coupling
to the tag will be better. At 125KHz, the coupling is
primarily magnetic (like a transformer) rather than
electomagnetic (like a radio). More primary turns should
give you better coupling.

Jim


On Fri, 23 Sep 2005 09:22:53 +1000
 "Ivan Vernot" <ivernot@optushome.com.au> wrote:
> Thanks Zack,
> After seeing your post I checked Digi-Key.
> As far as I can see, they only carry the 'TIRIS' (Texas
> Instruments RFID) 
> stuff.
> It is at 132KHz and uses quite large (~1m) antennae.
> 
> I am after an antenna <100mm long  (65mm round would be
> perfect) for use in 
> a 125KHz proximity card reader (think of an access
> control application)
> 
> BTW: I am in Sydney Australia.
> 
> Thanks for the reply.
> Cheers,
> Ivan
> 
> 
> ----- Original Message ----- 
> From: "Zack Widup" <w9sz@prairienet.org>
> To: <AVR-Chat@yahoogroups.com>
> Sent: Wednesday, September 21, 2005 10:25 PM
> Subject: Re: [AVR-Chat] OT: Where to get Custom Coils
> would
> 
> 
> >
> > Hi Ivan,
> >
> > You didn't say where you are located.  Can you order
> from Digi-Key?  They
> > have a whole assortment of RFID antennas and coils in
> their catalog.
> >
> > Zack
> >
> > On Wed, 21 Sep 2005, Ivan Vernot wrote:
> >
> >> Hello All,
> >> Apologies for off topic post but I'm using an AVR for
> this gadget ;-)
> >>
> >> I  am looking for a supplier that is able to wind an
> open core coil to be 
> >> used in an RFID application.
> >> The coil is used for the antenna of the RFID system
> and is typically a 
> >> few tens of turns in reasonable heavy gauge wire
> (30AWG or so) so that is 
> >> it relatively self supporting.
> >>
> >> Does anyone know of a supplier that can supply such
> coils in <1K qty?
> >>
> >> Kind Regards
> >>
> >> Ivan Vernot
> >>
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> > 
> 
> 
> 
> ------------------------ Yahoo! Groups Sponsor
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> 
> 
>  
> Yahoo! Groups Links
> 
> 
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>  
> 
> 

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At 09:22 AM 23/09/2005, you wrote:
>I am after an antenna <100mm long  (65mm round would be perfect) for use in
>a 125KHz proximity card reader (think of an access control application)

Have you tried Omron? Unfortunately the person looking after
RFID is in Hong Kong for another week or so.

Regards

John Samperi

******************************************************
                         Ampertronics Pty. Ltd.
   11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
          Tel. (02) 9674-6495       Fax (02) 9674-8745
                Email: samperi@ampertronics.com.au
                  Website  http://www.ampertronics.com.au
* Electronic Design   * Custom Products   * Contract Assembly
******************************************************

Hi Jim,
That sounds like a great idea. Doing it on a PCB would mean that each 
antenna will be identical (and saves all that winding :-)).
The problem (for me) though is how do I work out how many turns I need (how 
wide the tracks need to be, etc.)
If you have any links I could checkout I'd appreciate it.
Cheers,
Ivan

----- Original Message ----- 

From: "Jim Wagner" <jim_d_wagner@applelinks.net>
To: <AVR-Chat@yahoogroups.com>
Sent: Friday, September 23, 2005 9:27 AM
Subject: Re: [AVR-Chat] OT: Where to get Custom Coils would


> Make yourself an antenna with a spiral trace on a circuit
> board! Resonate it with a capacitor to 125KHz and you
> should be in. The more sprirals, you have, the better,
> because the resonating cap will be smaller and the coupling
> to the tag will be better. At 125KHz, the coupling is
> primarily magnetic (like a transformer) rather than
> electomagnetic (like a radio). More primary turns should
> give you better coupling.
>
> Jim
>
>
> On Fri, 23 Sep 2005 09:22:53 +1000
> "Ivan Vernot" <ivernot@optushome.com.au> wrote:
>> Thanks Zack,
>> After seeing your post I checked Digi-Key.
>> As far as I can see, they only carry the 'TIRIS' (Texas
>> Instruments RFID)
>> stuff.
>> It is at 132KHz and uses quite large (~1m) antennae.
>>
>> I am after an antenna <100mm long  (65mm round would be
>> perfect) for use in
>> a 125KHz proximity card reader (think of an access
>> control application)
>>
>> BTW: I am in Sydney Australia.
>>
>> Thanks for the reply.
>> Cheers,
>> Ivan
>>
>>
>> ----- Original Message ----- 
>> From: "Zack Widup" <w9sz@prairienet.org>
>> To: <AVR-Chat@yahoogroups.com>
>> Sent: Wednesday, September 21, 2005 10:25 PM
>> Subject: Re: [AVR-Chat] OT: Where to get Custom Coils
>> would
>>
>>
>> >
>> > Hi Ivan,
>> >
>> > You didn't say where you are located.  Can you order
>> from Digi-Key?  They
>> > have a whole assortment of RFID antennas and coils in
>> their catalog.
>> >
>> > Zack
>> >
>> > On Wed, 21 Sep 2005, Ivan Vernot wrote:
>> >
>> >> Hello All,
>> >> Apologies for off topic post but I'm using an AVR for
>> this gadget ;-)
>> >>
>> >> I  am looking for a supplier that is able to wind an
>> open core coil to be
>> >> used in an RFID application.
>> >> The coil is used for the antenna of the RFID system
>> and is typically a
>> >> few tens of turns in reasonable heavy gauge wire
>> (30AWG or so) so that is
>> >> it relatively self supporting.
>> >>
>> >> Does anyone know of a supplier that can supply such
>> coils in <1K qty?
>> >>
>> >> Kind Regards
>> >>
>> >> Ivan Vernot
>> >>
>> >
>> >
>> >
>> >
>> >
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>>
>> ------------------------ Yahoo! Groups Sponsor
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>>
>
> ---------------------------------------------------------------
> The Think Different Store
> http://www.thinkdifferentstore.com/
> For All Your Mac Gear
> ---------------------------------------------------------------
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>
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>
> Yahoo! Groups Links
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