Driver to drive?

Spehro Pefhany · Aug 23, 2013

On Thu, 22 Aug 2013 10:48:26 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

Nice thanks, I've been sorta penciling tantalums out of my design brain. Though I did use a big one ~100uF for a triangle wave thingie years ago.
The one 'gotcha' you left out was a clean voltage reference for the comparator. I semi-screwed up the above triangle wave generator and used the positive supply rail as the reference. There was this little occasional 'hick-up' in the frequency when a 'bang-bang' heater circuit in the same instrument would turn on and drop the positive rail by some ~10's of mV.

George H.

Yup.. even though the value of the supply voltage cancels out (if
stable), any noise or other variations in the reference/charging
voltage during a cycle will result in shorter (usually the problem) or
longer time. So you usually will want to use the same regulated
voltage for both RC charging and for the voltage reference.

It's tempting to try to coax a bit more time out of a given value of
(expensive) film cap by pushing further out on the RC curve, but that
increases noise sensitivity, so it's probably best to stick to around
one time constant unless you've carefully designed around that kind of
requirement.

John Fields · Aug 23, 2013

On Fri, 23 Aug 2013 01:34:31 +1000, "Phil Allison" <phil_a@tpg.com.au>
wrote:

"John Fields"

Nichrome has about a tenth the tempco of tungsten:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

--

** Arrant nonsense.

See table at bottom of this link:

http://en.wikipedia.org/wiki/Nichrome

The actual tempco is slightly non linear and WAAAY less than tungsten or
copper.

Plus 6% at 2000C.

Tungsten is nearly plus 1200 % at the same temp.

---
Note that the resistance you refer to is at about 1100C, while a
tungsten filament runs at about 3000C:

http://hypertextbook.com/facts/1999/AlexanderEng.shtml

With that in mind we can say:

Rt = Ro (1 + alpha T)

Where Rt is the resistance at the desired temperature,
Rt is the resistance at 0C,
alpha is the thermal coefficient of resistance, and
T is the desired temperature.

From the hyperphysics link at:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

We find that Nichrome A has an alpha of 0.0004, while tungsten's is
0.0045.

For a 10 ohm sample of Nichrome A wire, then, we have:

Rt = Ro (1 + alpha T)
= 10 * (1 + (0.0004 * 1100))
= 14.4 ohms.

In the same vein, for a 10 ohm sample of tungsten wire, we have:

Rt = Ro (1 + alpha T)
= 10 * (1 + (0.0045 * 3000)
= 145 ohms.

"Arrant nonsense"?

Hardly.

--
JF

Aug 23, 2013

On Tuesday, August 20, 2013 5:12:28 PM UTC-4, Guv Bob wrote:

Names can be confusing, so here's what I'm doing....

http://img43.imageshack.us/img43/7434/wvm.gif

When 12VDC is applied to the input, I need a 12VDC output for 5 seconds. Then output will go back off and stay off until the input goes to zero. Then cycle starts again.

Current for both legs is in the 10-50ma range.

A simple on-delay timer would work but I'm having trouble finding one with NC contacts. Tons of stuff $100+, but for this application, it has to be under $20.

Based on your limited information, the CD4060 would be a better choice than the 555, but if this is automotive, industrial, or some other less than ideal environment, things get complicated real fast regardless of the parts used:

Please view in a fixed-width font such as Courier.

..
..
..
..
..12VDC >---+-------+----------------------+---+---+---o------v N.O.
.. | | | | | ------o--->
.. | +--------. | | | ---------
.. | | | | | +--|\ \ \ \ \|--.
.. | | | | | | + --------- - |
.. | --- | | | | 12VDC |
.. | --- 0.22u | | | | |
.. | | X7R | | | |1N4148 |
.. | --- | | | '--|<|---[120]--+
.. | /// | | | |
.. |0.22u | | | |/
.. === X7R | | '--[5.6K]--+---+--| 100V
.. | | | | | |> npn
.. | | | [10K] | |TIPX
.. 1N4148| | '-------. | | ---
.. .-|>|--+ | | --- | ///
.. | | | | /// |
.. --- [10K] | [33K] |
.. /// | ----------------------- | |
.. | | VDD | | |
.. | | | | |/
.. +------|RST CD4060 Q14|-+-|<|-+-|>|-+--| 2N3904
.. | | | | 2x 1N4148 | |>
.. [220K] | ---- | | [10K] |
.. | |Phi1 Phi0 Phi0 GND| | | |
.. | ---------+------------- | '----+
.. --- | | | | | ---
.. /// | | | --- | ///
.. | | | /// |
.. +-------|------|--|<|---'
.. | | | 1N4148
.. | | |
.. [680K] [300K] ===
.. | | | 470p
.. '-------+------' NP0
..
..
..
..
..
..

George Herold · Aug 23, 2013

On Thursday, August 22, 2013 7:47:58 PM UTC-4, Phil Allison wrote:

"John Fields is an IDIOT "

Nichrome has about a tenth the tempco of tungsten:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

** Arrant nonsense.

See table at bottom of this link:

http://en.wikipedia.org/wiki/Nichrome

The actual tempco is slightly non linear and WAAAY less than tungsten or

copper.

Plus 6% at 2000C.

Tungsten is nearly plus 1200 % at the same temp.

---

Note that the resistance you refer to is at about 1100C, while a

tungsten filament runs at about 3000C:

** Totally irrelevant.

With that in mind we can say:

Rt = Ro (1 + alpha T)

** Nichrome ( along with other low tempco alloys) does NOT follow that

formula.

The resistance barely changes from room temp to red hot.

http://www.wiretron.com/nicrdat.html

You are using YOUR ERROR in your false proof.

Piss off - you fucking fuckwit.

... Phil

(sorry for all the double space crap)
JF I gotta go with Phil here. I measured the resistance of a light bulb
a few weeks ago. I didn't get it up the the max voltage, and still R went up by a factor of 8. If nichrome is only 6% that would be sweet.
(I'm thinking of measuring the johnson noise, as we all know a changing source impedance is a pita.) I'll post any nichrome numbers when I get them.
Hey let's not have any yelling. Things have been much more 'civil' on SED lately. It's nice!

George H.

Michael A. Terrell · Aug 23, 2013

Jim Thompson wrote:

Michael A. Terrell wrote:

Some programmers need a 'Don't bother' instruction.

Trying to read ADI's model, it looks as if the "designer" got carried
away with nested IF statements and bungled it.

Except for transient response being its own block, I think I can write
down the whole AD8218 behavior as a single EVALUE statement >:-}

Make sure you send them an encrypted copy. ;-)

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

Jim Thompson · Aug 23, 2013

On Thu, 22 Aug 2013 17:35:17 -0400, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Jim Thompson wrote:

Michael A. Terrell wrote:

Some programmers need a 'Don't bother' instruction.

Trying to read ADI's model, it looks as if the "designer" got carried
away with nested IF statements and bungled it.

Except for transient response being its own block, I think I can write
down the whole AD8218 behavior as a single EVALUE statement >:-}

Make sure you send them an encrypted copy. ;-)

Phil Allison · Aug 23, 2013

"John Fields is an IDIOT "

Nichrome has about a tenth the tempco of tungsten:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

** Arrant nonsense.

See table at bottom of this link:

http://en.wikipedia.org/wiki/Nichrome

The actual tempco is slightly non linear and WAAAY less than tungsten or
copper.

Plus 6% at 2000C.

Tungsten is nearly plus 1200 % at the same temp.

---
Note that the resistance you refer to is at about 1100C, while a
tungsten filament runs at about 3000C:

** Totally irrelevant.

With that in mind we can say:

Rt = Ro (1 + alpha T)

** Nichrome ( along with other low tempco alloys) does NOT follow that
formula.

The resistance barely changes from room temp to red hot.

http://www.wiretron.com/nicrdat.html

You are using YOUR ERROR in your false proof.

Piss off - you fucking fuckwit.

.... Phil

Tom Del Rosso · Aug 23, 2013

Jim Thompson wrote:

On Thu, 22 Aug 2013 17:35:17 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

Make sure you send them an encrypted copy. ;-)

Bwahahahahahaha!

But, no, my aim is to try to kill off this trend to only provide
simulation on your own proprietary simulator. I really think it's
dumb.

I think the first step toward that goal is to send them an encrypted copy.

--

Reply in group, but if emailing remove the last word.

George Herold · Aug 23, 2013

On Thursday, August 22, 2013 7:19:10 PM UTC-4, bloggs.fred...@gmail.com wrote:

On Tuesday, August 20, 2013 5:12:28 PM UTC-4, Guv Bob wrote:

Names can be confusing, so here's what I'm doing....

http://img43.imageshack.us/img43/7434/wvm.gif

When 12VDC is applied to the input, I need a 12VDC output for 5 seconds. Then output will go back off and stay off until the input goes to zero. Then cycle starts again.

Current for both legs is in the 10-50ma range.

A simple on-delay timer would work but I'm having trouble finding one with NC contacts. Tons of stuff $100+, but for this application, it has to be under $20.

Based on your limited information, the CD4060 would be a better choice than the 555, but if this is automotive, industrial, or some other less than ideal environment, things get complicated real fast regardless of the parts used:

Hi Fred, a counter solution is nice. Can I ask a silly question?
Where the bleep is the oscillator? The R's and C tied to the Phi inputs?

Thanks,
George H.

Please view in a fixed-width font such as Courier.

.

.

.

.

.12VDC >---+-------+----------------------+---+---+---o------v N.O.

. | | | | | ------o---

. | +--------. | | | ---------

. | | | | | +--|\ \ \ \ \|--.

. | | | | | | + --------- - |

. | --- | | | | 12VDC |

. | --- 0.22u | | | | |

. | | X7R | | | |1N4148 |

. | --- | | | '--|<|---[120]--+

. | /// | | | |

. |0.22u | | | |/

. === X7R | | '--[5.6K]--+---+--| 100V

. | | | | | |> npn

. | | | [10K] | |TIPX

. 1N4148| | '-------. | | ---

. .-|>|--+ | | --- | ///

. | | | | /// |

. --- [10K] | [33K] |

. /// | ----------------------- | |

. | | VDD | | |

. | | | | |/

. +------|RST CD4060 Q14|-+-|<|-+-|>|-+--| 2N3904

. | | | | 2x 1N4148 | |

. [220K] | ---- | | [10K] |

. | |Phi1 Phi0 Phi0 GND| | | |

. | ---------+------------- | '----+

. --- | | | | | ---

. /// | | | --- | ///

. | | | /// |

. +-------|------|--|<|---'

. | | | 1N4148

. | | |

. [680K] [300K] ===

. | | | 470p

. '-------+------' NP0

.

.

.

.

.

.

Aug 23, 2013

Hi Fred, a counter solution is nice. Can I ask a silly question?

Where the bleep is the oscillator? The R's and C tied to the Phi inputs?

Classic 3-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

..
..
..
..
..
..
.. ____
.. Phi1 |\ |\ Phi0 |\ Phi0
.. .-| o-----| o---+---| o--+---->
.. | |/ |/ | |/ |
.. | [R] |
.. | | C |
.. '----[R']-------+---||---'
..
..
..

Aug 23, 2013

On Wednesday, August 21, 2013 11:48:28 AM UTC-4, Jim Thompson wrote:

On Tue, 20 Aug 2013 16:40:51 -0700, Jim Thompson

To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

AD8218_HighSideSense: ADI Model Produces Output Above Rail and Below

Ground

See attachment >:-}

...Jim Thompson

Interesting further FUBAR... ADI's model sort of works correctly at

0Amps with ENB grounded, not perfectly, but close.

Looks like someone got tangled up in their "IF" statements >:-}

...Jim Thompson

--

| James E.Thompson | mens |

| Analog Innovations | et |

| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |

| San Tan Valley, AZ 85142 Skype: Contacts Only | |

| Voice480)460-2350 Fax: Available upon request | Brass Rat |

| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Why would anyone want to SPICE that component?

Aug 23, 2013

On Friday, August 23, 2013 9:10:20 AM UTC-4, George Herold wrote:

Make that the classic 2-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

..
..
..
..
..
..
.. ____
.. Phi1 |\ Phi0 |\ Phi0
.. .---| o---+---| o--+---->
.. | |/ | |/ |
.. [R'] [R] |
.. | | C |
.. '---------+---||---'
..
..
..

Aug 23, 2013

On Friday, August 23, 2013 11:49:54 AM UTC-4, Jim Thompson wrote:

On Fri, 23 Aug 2013 06:41:21 -0700 (PDT),

bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, August 23, 2013 9:10:20 AM UTC-4, George Herold wrote:

Make that the classic 2-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as

Courier.

.

.

.

.

.

.

. ____

. Phi1 |\ Phi0 |\ Phi0

. .---| o---+---| o--+----

. | |/ | |/ |

. [R'] [R] |

. | | C |

. '---------+---||---'

.

.

.

As in my ancient RCA data book...

http://www.analog-innovations.com/SED/CMOS-Oscillators.pdf

...Jim Thompson

--

| James E.Thompson | mens |

| Analog Innovations | et |

| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |

| San Tan Valley, AZ 85142 Skype: Contacts Only | |

| Voice480)460-2350 Fax: Available upon request | Brass Rat |

| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

There's something about the 2-inverter that tends to hang at small time constant and squegg at large time constant. I think they discovered that after the 4060 was in production.

whit3rd · Aug 23, 2013

On Tuesday, August 13, 2013 11:46:06 AM UTC-7, TTman wrote:

Any simple way to dump 500Watts fixed @100 volts ? Or is it easier to have

5 x 100R 100Watt resistors and a big heat sink ? test time would be

1minute...

That's a lot of heat, even for just one minute. The immersible elements
for 5kW/220 V water heaters are about 20 ohms (two elements per
appliance, Vsquared/R = 2500W).

So your high-power resistor is an item that can be found two at a time
in old scrapped hot water heaters. Any plumber can unbolt a few
before his next visit to a recycler. A flow of water, or a bucket of water, should
cool it well enough.

Jim Thompson · Aug 23, 2013

On Fri, 23 Aug 2013 06:29:08 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Wednesday, August 21, 2013 11:48:28 AM UTC-4, Jim Thompson wrote:
On Tue, 20 Aug 2013 16:40:51 -0700, Jim Thompson

To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

AD8218_HighSideSense: ADI Model Produces Output Above Rail and Below

Ground

See attachment >:-}

...Jim Thompson

Interesting further FUBAR... ADI's model sort of works correctly at

0Amps with ENB grounded, not perfectly, but close.

Looks like someone got tangled up in their "IF" statements >:-}

...Jim Thompson

--

| James E.Thompson | mens |

| Analog Innovations | et |

| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |

| San Tan Valley, AZ 85142 Skype: Contacts Only | |

| Voice480)460-2350 Fax: Available upon request | Brass Rat |

| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Why would anyone want to SPICE that component?

Jim Thompson · Aug 23, 2013

On Fri, 23 Aug 2013 06:27:21 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

Hi Fred, a counter solution is nice. Can I ask a silly question?

Where the bleep is the oscillator? The R's and C tied to the Phi inputs?

Classic 3-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

.
.
.
.
.
.
. ____
. Phi1 |\ |\ Phi0 |\ Phi0
. .-| o-----| o---+---| o--+----
. | |/ |/ | |/ |
. | [R] |
. | | C |
. '----[R']-------+---||---'
.
.
.

Jim Thompson · Aug 23, 2013

On Fri, 23 Aug 2013 06:41:21 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, August 23, 2013 9:10:20 AM UTC-4, George Herold wrote:

Make that the classic 2-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

.
.
.
.
.
.
. ____
. Phi1 |\ Phi0 |\ Phi0
. .---| o---+---| o--+----
. | |/ | |/ |
. [R'] [R] |
. | | C |
. '---------+---||---'
.
.
.

Spehro Pefhany · Aug 23, 2013

On Fri, 23 Aug 2013 08:49:54 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 23 Aug 2013 06:41:21 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, August 23, 2013 9:10:20 AM UTC-4, George Herold wrote:

Make that the classic 2-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

.
.
.
.
.
.
. ____
. Phi1 |\ Phi0 |\ Phi0
. .---| o---+---| o--+----
. | |/ | |/ |
. [R'] [R] |
. | | C |
. '---------+---||---'
.
.
.

As in my ancient RCA data book...

http://www.analog-innovations.com/SED/CMOS-Oscillators.pdf

...Jim Thompson

If you're making this with CMOS gate chips, it's a good idea to stick
to the unbuffered variety. The usual (these days) buffered gates can
ring on the transitions. Somtimes.

John Fields · Aug 23, 2013

On Fri, 23 Aug 2013 09:47:58 +1000, "Phil Allison" <phil_a@tpg.com.au>
wrote:

"John Fields is an IDIOT "

Nichrome has about a tenth the tempco of tungsten:

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rstiv.html

** Arrant nonsense.

See table at bottom of this link:

http://en.wikipedia.org/wiki/Nichrome

The actual tempco is slightly non linear and WAAAY less than tungsten or
copper.

Plus 6% at 2000C.

Tungsten is nearly plus 1200 % at the same temp.

---
Note that the resistance increase you refer to is for is at about 1100C, while a
tungsten filament runs at about 3000C:

** Totally irrelevant.

---
Not at all, since what would be fair would be to compare the
resistances of the wires over the same temperature range.

What you've done is to look at the 6% increase for nichrome from 20C
to about 1100C, while claiming an increase for tungsten of 1200% over
the same range, when that increase is only valid for tungsten from 20C
to about 3000C

With that in mind we can say:

Rt = Ro (1 + alpha T)

** Nichrome ( along with other low tempco alloys) does NOT follow that
formula.

---
I can't see why not, since the formula's only a procedure and as long
as you know the thermal coefficient of resistance and the end
temperatures, plug 'em into the formula and out comes resistance.

There's a little error in there because of the change in tempco with
temperature, but it's miniscule and certainly hardly matters for the
purpose at hand.
---

The resistance barely changes from room temp to red hot.

http://www.wiretron.com/nicrdat.html

You are using YOUR ERROR in your false proof.

Piss off - you fucking fuckwit.

---
You don't know what you're talking about.

--
JF

Jim Thompson · Aug 23, 2013

On Fri, 23 Aug 2013 12:11:27 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Fri, 23 Aug 2013 08:49:54 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 23 Aug 2013 06:41:21 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, August 23, 2013 9:10:20 AM UTC-4, George Herold wrote:

Make that the classic 2-inverter CMOS RC-oscillator:

Please view in a fixed-width font such as
Courier.

.
.
.
.
.
.
. ____
. Phi1 |\ Phi0 |\ Phi0
. .---| o---+---| o--+----
. | |/ | |/ |
. [R'] [R] |
. | | C |
. '---------+---||---'
.
.
.

As in my ancient RCA data book...

http://www.analog-innovations.com/SED/CMOS-Oscillators.pdf

...Jim Thompson

If you're making this with CMOS gate chips, it's a good idea to stick
to the unbuffered variety. The usual (these days) buffered gates can
ring on the transitions. Somtimes.

Driver to drive?

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