Driver to drive?

John Larkin · Feb 7, 2012

On Mon, 06 Feb 2012 20:58:54 -0800, josephkk
<joseph_barrett@sbcglobal.net> wrote:

On Thu, 02 Feb 2012 05:22:23 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Thu, 02 Feb 2012 11:55:35 +0000, Pomegranate Bastard <pommyB@dsl.pipex.com
wrote:

On Tue, 31 Jan 2012 19:07:25 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 31 Jan 2012 18:17:26 -0800, MassiveProng
MassiveProng@thebarattheendoftheuniverse.org> wrote:

On 31 Jan 2012 15:52:23 GMT, John Doe <jdoe@usenetlove.invalid> wrote:

Nobody forces anybody else to do anything on UseNet. Your mother
should have taught you self-control.

Nobody forces you to make absolutely retarded, meaningless posts, yet
you insist on doing so. The word is Usenet, idiot.

Your RETARDED, CRIMINAL mother should be jailed for failing to flush
you, the moment the stupid slut shat you.

You keep repeating that image. That's sick in so many way

This is Nymbecile's favourite insult.

It's yet another demonstration of what a sad, useless life this
imbecile leads.

Yet other imbeciles persist in feeding the troll, ensuring his position at the
podium. If everyone shunned him, he'd become invisible... and cease being
annoying.

...Jim Thompson

Larkin's narcissism is such that he thinks he can rescue even such as
NymNoNuts.

?-)

It never hurts to experiment.

--

John Larkin, President
Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation

The_Giant_Rat_of_Sumatra · Feb 8, 2012

On Tue, 07 Feb 2012 11:01:37 -0500, JW <none@dev.null> wrote:

*Guffaw!*

That went out of use even before retards like you started re-using it
in Usenet.

It is even more archaic than fucktards like you who use it are.

You're a fucking retard, guffaw boy.

John Larkin · Feb 8, 2012

On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodboat@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

Jim Thompson · Feb 8, 2012

On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodboat@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Jim Thompson · Feb 8, 2012

On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
[snip]

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Jupiter Jaq · Feb 8, 2012

On Tue, 07 Feb 2012 20:53:38 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

Precise small-signal slope (assuming no resistive part) is kT/qI, or
~26/I(in mA) at 300°K

...Jim Thompson

Tada!

George Herold · Feb 8, 2012

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.- Hide quoted text -

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

josephkk · Feb 8, 2012

On Sun, 05 Feb 2012 16:45:33 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 05 Feb 2012 15:13:38 -0800, josephkk
joseph_barrett@sbcglobal.net> wrote:

On Thu, 02 Feb 2012 21:09:10 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 02 Feb 2012 20:28:15 -0800, josephkk
joseph_barrett@sbcglobal.net> wrote:

On Sat, 28 Jan 2012 17:42:27 -0800, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

I don't really think an "arbitrary" definition is necessary, since the
location of the knee has been with us for decades.

John, I told you there are people who believe there is a "knee" in an
exponential function. ;-)

And there are people who think that the only kind of resistance is
E/I.

Some famous person once said "When all you know is Ohm's Law,
everything looks like a resistor."

Well, that was me, actually.

Switch famous to infamous and the description of yourself is all too apt.

?-)

After almost a week of brooding, that's all you can come up with?

Naw, it is all you are worth. But it is fun to rag on your vainglory.

?-)

That took three days?

Not at all, more like 30 seconds. Sometimes i have other things to do
besides read Usenet. Tough it out pumpkin.

?-)

John Larkin · Feb 8, 2012

On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.- Hide quoted text -

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

JW · Feb 8, 2012

On Tue, 07 Feb 2012 17:59:33 -0800 The_Giant_Rat_of_Sumatra
<GeorgeTirebiter@drmemory.org> wrote in Message id:
<ill3j7l6kgb6g395pv92fgq5rff5tg9mts@4ax.com>:

[...] the usual whinging.

Yawn.

Jim Thompson · Feb 8, 2012

On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gherold@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.- Hide quoted text -

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

George Herold · Feb 8, 2012

On Feb 8, 9:48 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food..- Hide quoted text -

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

Huh? It does, but George was taking about the kT/qI portion...
450/300=1.5 ;-)

Opps, I was talking about the resistive part. It should also scale
with the absolute temperature, if the resistance is from some hunk of
'metal'.

Figure 3 in the 1n4148 data sheet that someone linked to.

(I'd just been thinking about the Wiedeman-Franz law from Jamie's MAF
post.)

George H.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.- Hide quoted text -

- Show quoted text -

John Larkin · Feb 8, 2012

On Wed, 8 Feb 2012 07:32:11 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Feb 8, 9:48 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.- Hide quoted text -

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

Huh? It does, but George was taking about the kT/qI portion...
450/300=1.5 ;-)

Opps, I was talking about the resistive part. It should also scale
with the absolute temperature, if the resistance is from some hunk of
'metal'.

Yes, I thought you were. JT's comment didn't make sense.

--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

John Larkin · Feb 8, 2012

On Wed, 08 Feb 2012 05:44:39 -0500, JW <none@dev.null> wrote:

On Tue, 07 Feb 2012 17:59:33 -0800 The_Giant_Rat_of_Sumatra
GeorgeTirebiter@drmemory.org> wrote in Message id:
ill3j7l6kgb6g395pv92fgq5rff5tg9mts@4ax.com>:

[...] the usual whinging.

Yawn.

That's British for "whining", isn't it? How is that pronounced?

--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

Michael A. Terrell · Feb 8, 2012

"krw@att.bizzzzzzzzzzzz" wrote:

...it's like he was insulting your manhood. You certainly respond as such. I
wonder what Freud would have to say?

Sometimes a troll is just a troll...

--
You can't have a sense of humor, if you have no sense.

Jim Thompson · Feb 8, 2012

On Wed, 08 Feb 2012 08:49:11 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 8 Feb 2012 07:32:11 -0800 (PST), George Herold
gherold@teachspin.com> wrote:

On Feb 8, 9:48 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
[snip]

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

Huh? It does, but George was taking about the kT/qI portion...
450/300=1.5 ;-)

Opps, I was talking about the resistive part. It should also scale
with the absolute temperature, if the resistance is from some hunk of
'metal'.

Yes, I thought you were. JT's comment didn't make sense.

Why? Because you don't understand kT/qI ?

Perfect diode, no resistive term, DYNAMIC impedance scales linearly
with temperature (°K). So a perfect diode operating a 26mA at 300°K
has a DYNAMIC impedance of 1 Ohm; and 1.5 Ohm DYNAMIC impedance at
450°K.

Perhaps someone would plot 1N4148 forward drop on LOG paper so we can
easily see the bulk R breakpoint (and the _dirt_ at low currents, the
ISR coefficient in the model).

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice

Jim Thompson · Feb 8, 2012

On Wed, 08 Feb 2012 13:19:16 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

"krw@att.bizzzzzzzzzzzz" wrote:

...it's like he was insulting your manhood. You certainly respond as such. I
wonder what Freud would have to say?

Sometimes a troll is just a troll...

Jim Thompson · Feb 8, 2012

On Wed, 8 Feb 2012 12:01:44 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Feb 8, 1:49 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Wed, 08 Feb 2012 08:49:11 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Wed, 8 Feb 2012 07:32:11 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 8, 9:48 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
[snip]

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

Huh? It does, but George was taking about the kT/qI portion...
450/300=1.5 ;-)

Opps, I was talking about the resistive part. It should also scale
with the absolute temperature, if the resistance is from some hunk of
'metal'.

Yes, I thought you were. JT's comment didn't make sense.

Why? Because you don't understand kT/qI ?

Perfect diode, no resistive term, DYNAMIC impedance scales linearly
with temperature (°K). So a perfect diode operating a 26mA at 300°K
has a DYNAMIC impedance of 1 Ohm; and 1.5 Ohm DYNAMIC impedance at
450°K.

Perhaps someone would plot 1N4148 forward drop on LOG paper so we can
easily see the bulk R breakpoint (and the _dirt_ at low currents, the
ISR coefficient in the model).

Oh, I'm all set up to do that. (testing diode thermometers)
Here's a link...(Image shack now wants me to register, so that's the
end of that.)

http://tinypic.com/view.php?pic=257df06&s=5

I could only get to 10mA. (The most my current source will do.) So
not into the ohmic region. The straight line is drawn by eye.

George H.

...Jim Thompson
[snip]

Jim Thompson · Feb 8, 2012

On Wed, 8 Feb 2012 12:08:24 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Feb 8, 3:01 pm, George Herold <gher...@teachspin.com> wrote:
On Feb 8, 1:49 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-

Web-Site.com> wrote:
On Wed, 08 Feb 2012 08:49:11 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Wed, 8 Feb 2012 07:32:11 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 8, 9:48 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 22:09:33 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 7 Feb 2012 19:39:47 -0800 (PST), George Herold
gher...@teachspin.com> wrote:

On Feb 7, 9:53 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Tue, 07 Feb 2012 18:40:31 -0800, John Larkin

jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 5 Feb 2012 17:22:24 -0800 (PST), dagmargoodb...@yahoo.com
wrote:

On Feb 5, 5:39 pm, Jim Thompson wrote:
On Sun, 05 Feb 2012 14:08:18 -0800, John Larkin wrote:
On Sun, 05 Feb 2012 13:28:58 -0700, Jim Thompson wrote:

So far, life has been a huge amount of fun. But what does that have to
do with diodes?

The same as talking amps of current in a 1N4148.

http://www.nxp.com/documents/data_sheet/1N4148_1N4448.pdf

Looks effectively ohmic above 50mA (Fig. 3).

Yup. The slope is just about 1 ohm. The dynamic impedance of a PN
junction is 1 ohm at 25 mA.

Closer to 26mA ;-)

...Jim Thompson
--
[snip]

- Show quoted text -

1 ohm is a pretty good number for a small junction. I measured a
2n3904 about the same.

Neat, how the resistance goes to ~1.5 ohms at ~450K.

George H.

Yup, the ohmic part has a positive TC.

Huh? It does, but George was taking about the kT/qI portion...
450/300=1.5 ;-)

Opps, I was talking about the resistive part. It should also scale
with the absolute temperature, if the resistance is from some hunk of
'metal'.

Yes, I thought you were. JT's comment didn't make sense.

Why? Because you don't understand kT/qI ?

Perfect diode, no resistive term, DYNAMIC impedance scales linearly
with temperature (°K). So a perfect diode operating a 26mA at 300°K
has a DYNAMIC impedance of 1 Ohm; and 1.5 Ohm DYNAMIC impedance at
450°K.

Perhaps someone would plot 1N4148 forward drop on LOG paper so we can
easily see the bulk R breakpoint (and the _dirt_ at low currents, the
ISR coefficient in the model).

Oh, I'm all set up to do that. (testing diode thermometers)
Here's a link...(Image shack now wants me to register, so that's the
end of that.)

http://tinypic.com/view.php?pic=257df06&s=5

I could only get to 10mA. (The most my current source will do.) So
not into the ohmic region. The straight line is drawn by eye.

George H.

Oh I forgot to add that at 10mA the diode was heating up and the
forward voltage dropping, so the 725 mV number was the first thing the
DMM registered... and readings went down from there.

Geo

...Jim Thompson
[snip]

Don Y · Feb 8, 2012

Hi Mike,

On 2/8/2012 12:00 PM, amdx wrote:

Hi All,
I'm on a boat, about 170ft from the utility post.
Recently our cable company switched to the wonderful world of
Digital TV. I got the new digital converter and had no picture.
I took the box back and got a second box, still no picture. So now I
suspect a weak signal and confirm that it is the cable length. The cable

I assume you couldn't drag your cable box (electrically) closer to the
drop "for test purposes" (e.g., even if you needed a small inverter
to power the kit)

company came out and gave me a better cable than I had installed. At
this point I have a picture but it is intermittent. The signal at the
utility post has 3 outputs and had a four way splitter, I suggested the

Why? Are there other clients feeding off the same drop? I.e., 86
the splitter completely.

cable guy put in two 2 way splitters and give me the stronger (first) tap.
That got my signal to work almost all the time. I'd like to get the
signal to work 100% of the time.
I don't has access to electricity at the utility post, so an amp is out.
Although I could try an amp at the cable box end. Is that reasonable?

No. The signal is already lost when it gets to that end.
But an inline amplifier that you can power downstream (from *your*
end of the cable) with a power injector. Find something that is
reasonably weatherproof (unless you have a nice dry place to
install it at the post -- remember, salt water/spray is hell!).
And, consider how much risk of THEFT there might be...

(they aren't expensive but if others have the same problem
as you, they might opt to "borrow" your solution!)

I would run two cables if there was a way to make it increase signal
strength.

Nope.

Getting anymore from the cable company is not an option.
Any ideas to get a better signal?

Watch prerecorded movies off DVD -- there's nothing on TV
worth watching! :>

Driver to drive?

John Larkin

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