I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

I was motivated to take a look. I downloaded the zip to this Windows7 deal.
I could not open the .doc (if that's what it was.)
Pity! You probably mentioned the scorched galvanized sheet.
Oh well...

Brian W

On Mon, 20 Dec 2010 19:54:29 -0600, brian whatcott
wrote:

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

I was motivated to take a look. I downloaded the zip to this Windows7 deal.
I could not open the .doc (if that's what it was.)
Pity! You probably mentioned the scorched galvanized sheet.
Oh well...

Brian W


Brian it opened ok for me, and yes it is a .doc file

peter

On 12/21/2010 06:03 PM, Peter Dettmann wrote:
On Mon, 20 Dec 2010 19:54:29 -0600, brian whatcott
wrote:

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

I was motivated to take a look. I downloaded the zip to this Windows7 deal.
I could not open the .doc (if that's what it was.)
Pity! You probably mentioned the scorched galvanized sheet.
Oh well...

Brian W


Brian it opened ok for me, and yes it is a .doc file

peter



Yep worked fine here

using Open Office

On 12/22/2010 4:16 PM, philo wrote:
On 12/21/2010 06:03 PM, Peter Dettmann wrote:
On Mon, 20 Dec 2010 19:54:29 -0600, brian whatcott
wrote:

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

I was motivated to take a look. I downloaded the zip to this Windows7
deal.
I could not open the .doc (if that's what it was.)
Pity! You probably mentioned the scorched galvanized sheet.
Oh well...

Brian W


Brian it opened ok for me, and yes it is a .doc file

peter



Yep worked fine here

using Open Office

I had the 90-day trial version of office, which had timed out on a new
W7 box. So I downloaded open office (170MB +) and all was well. Thanks
for the hint.

Brian W

On 12/23/2010 06:56 PM, brian whatcott wrote:
On 12/22/2010 4:16 PM, philo wrote:
On 12/21/2010 06:03 PM, Peter Dettmann wrote:
On Mon, 20 Dec 2010 19:54:29 -0600, brian whatcott
wrote:

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

I was motivated to take a look. I downloaded the zip to this Windows7
deal.
I could not open the .doc (if that's what it was.)
Pity! You probably mentioned the scorched galvanized sheet.
Oh well...

Brian W


Brian it opened ok for me, and yes it is a .doc file

peter



Yep worked fine here

using Open Office

I had the 90-day trial version of office, which had timed out on a new
W7 box. So I downloaded open office (170MB +) and all was well. Thanks
for the hint.

Brian W





UR welcome

I do need no stinkin' Microsoft

On 12/20/2010 7:11 PM, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

OK Hopping back on topic. I recall that there are stiff materials -
like steel compared to aluminum,and stiff structures - like an aluminum
tube compared with a steel strip of the same weight per length.

In the same way, you have brought up negative resistance structures of
several designs, and I thought you were going to mention objects that
have a naturally -ve resistance region. And you did at one point.

I recall seeing on the net, some mention of an experimenter who scorched
some galvanized sheet and found that a point contract placed on it could
resonate a tuned circuit with its negative resistance.

Gotta love those folks.

Brian W

On Dec 24, 10:28*am, brian whatcott wrote:
On 12/20/2010 7:11 PM, Lemon Tree wrote:

I have posted a Negative Dynamic Resistance circuit collection along
with some other things he
http://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

OK Hopping back on topic. * * *I recall that there are stiff materials -
like steel compared to aluminum,and stiff structures - like an aluminum
tube compared with a steel strip of the same weight per length.

In the same way, you have brought up negative resistance structures of
several designs, and I thought you were going to mention objects that
have a naturally -ve resistance region. And you did at one point.

I recall seeing on the net, some mention of an experimenter who scorched
some galvanized sheet and found that a point contract placed on it could
resonate a tuned circuit with its negative resistance.

Gotta love those folks.

Brian W

Hey OM:

I remember way back when we used to take blue steel double edge razor
blades and make a point contact negative resistance diode from them, a
good ground, and mother oats box wrapped with wire and a long wire
antenna, wow

73 OM
de n8zu

On Dec 20, 5:11*pm, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things hehttp://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

FWIW, one well-known negative dynamic resistance element is (the input
side of) a switching power supply. If the supply maintains a nearly
constant efficiency with changing input voltage, and the output
supplies a constant-power load, then the input power is nearly
constant with changing input voltage: the current drops as the
voltage rises. Beware a few million personal computers on a power
grid: avoid letting them excite a resonance in the grid...

(Slightly off-topic: a Google search reveals that the power community
is indeed interested in grid resonances. See "Schumann Resonance,"
for example.)

Cheers,
Tom

On Dec 20, 5:11*pm, Lemon Tree wrote:
I have posted a Negative Dynamic Resistance circuit collection along
with some other things hehttp://code.google.com/p/lemontree/downloads/list
I am no Alan Yates however maybe you will find some things of
interest.
Sean O'Connor

Others that a search of your document didn't find:
--Tunnel diode
--Back diode
--Unijunction transistor
--Gas discharges (e.g., neon light bulbs and even arcs in air)

Historical note: the negative resistance of an arc was used to excite
an LC resonator in _arc_ (as opposed to spark) transmitters from a
century or so ago. I'm often amazed at what early radio engineers
were able to accomplish...

I guess there was a hint (at least, maybe more) in the text about
trigger diodes, commonly used to trigger SCRs and triacs.

Cheers,
Tom