audio recording on IC -help wanted

[Eeyore]

Terry Given wrote:

AIUI the US military wants new air frames designed for 100year lives.

Probably counter-productive for fighters.

The Russians went exactly the other way with modern Migs and Sukhois.

Graham

 

[Terry Given]

Ancient_Hacker wrote:

Joerg wrote:


Our here it isn't customary to take a whole airplane apart after 10
years. What is taken apart after 2000hrs or whatever their TBO rating
would be the engines.


Piston engines do need a major look-see and overhaul every 1K to 2K
hours. Lotsa pounding there. The cylinders have to be removed,
stripped with boiling lye, dipped in red dye, rolled in white powder,
and inspected for microscopic cracks.

Jet engines by comparison can run almost forever, only needing periodic
crack inspections by boroscope and X-Ray. Some of the parts on the hot
end do need periodic replacement as they anneal and corrode.

Planes are made of aluminum mostly, and aluminum gets tired after so
many flexings, so planes do have routine inspections, every xxx hours
or yyy trips for some parts, xxxx hours or yyyy trips for less stressed
parts. That was much easier when smoking was allowed, as even minor
cracks would be outlined in brown. Now they hafta run an eddy-current
probe over every dang square inch.

Every 15K flight hours or so they need a major inspection, which takes
many weeks to months of downtime as the wings have to be completely
opened up, the inside of the fuselage skin has to be inspected, and
worse.

The new jets will have mostly carbon fiber and epoxy composite skin,
which hopefully won't need the huge downtimes for inspections. No
fatigue cracking it seems. I hope they're right.

AIUI the US military wants new air frames designed for 100year lives.

Cheers
Terry

 

[Ancient_Hacker]

Joerg wrote:

Our here it isn't customary to take a whole airplane apart after 10
years. What is taken apart after 2000hrs or whatever their TBO rating
would be the engines.

Piston engines do need a major look-see and overhaul every 1K to 2K
hours. Lotsa pounding there. The cylinders have to be removed,
stripped with boiling lye, dipped in red dye, rolled in white powder,
and inspected for microscopic cracks.

Jet engines by comparison can run almost forever, only needing periodic
crack inspections by boroscope and X-Ray. Some of the parts on the hot
end do need periodic replacement as they anneal and corrode.

Planes are made of aluminum mostly, and aluminum gets tired after so
many flexings, so planes do have routine inspections, every xxx hours
or yyy trips for some parts, xxxx hours or yyyy trips for less stressed
parts. That was much easier when smoking was allowed, as even minor
cracks would be outlined in brown. Now they hafta run an eddy-current
probe over every dang square inch.

Every 15K flight hours or so they need a major inspection, which takes
many weeks to months of downtime as the wings have to be completely
opened up, the inside of the fuselage skin has to be inspected, and
worse.

The new jets will have mostly carbon fiber and epoxy composite skin,
which hopefully won't need the huge downtimes for inspections. No
fatigue cracking it seems. I hope they're right.

 

[Joerg]

Jan Panteltje wrote:

On a sunny day (Sat, 20 Jan 2007 20:37:07 GMT) it happened Joerg
notthisjoergsch@removethispacbell.net> wrote in
T3vsh.36327$Gr2.28275@newssvr21.news.prodigy.net>:


PIC 12F629 (8 pin DIL) is specified to work between 2V and 5.5 V.
It has an internal oscillator you can software calibrate, many more features.
And 1nA standby current.
The 12F675 also has a 10 bit AD.
I have used ten recently and so far no problems.
The 12F629 costs 0.67 $ in volume.
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1001&mid=10&lang=en&pageId=74

As you referred to 4060 I think this beats it every way, except price perhaps.
For things like prof equipment (like i nairplanes) the 67 cent x 2 cannot
possibly be a problem?


Add to that an LDO and low-ESR cap for 40c, comes to $1.74. I've got to
deal with a 4V to 9V range. Now the two 4060 chips plus two resistors
and one cap each add to a grand total of 35c, no LDO needed. Also, there
is only one LDO (TPS71xxx series) under 2.5uA and even that is a bit
painful in this app. Plus I had some not so good experiences with those.

The delays is all I need from them and the 4060 does this just fine.
Using a uC would have added NRE time and cost for the client while the
4060 just gets pulled from the CAD library and that's pretty much it.
Ok, I also need a reference here but a uC with that on board pops right
through the 80c barrier. Ye olde TLV431 for 8c or so will be fine.

This one isn't for an airplane but a semi-disposable and it is very
important to demonstrate the economic side of things. Two 67c micros
would freak everyone out

Even if it was for an airplane there is another side of this equation:
False alarm rate and stuff like that. Simplicity of your circuit is
rather essential and a uC doesn't exactly score that high. If you have a
solution that can live without code and with parts that can be backed up
with 30+ years of reliability data why not use it?

What could work would be two 4-bit micros as long as they are under 15c.


OK, but I do not see why 4 bit would be OK and 8 not.

The usual reason: $$$

Many times even a lowly 8-bit micro is just too expensive for a certain
job. Probably half a dozen times I thought that it'll be time to roll
one of my older designs to a uC solution. Called the client, asked for
the current cost and was blown away by the low Dollar number they
replied with. It's amazing what you can do with discretes these days.

One thing is very true, we do not know how long flash memory will last
(if I had to guarantee it), we will probably see many electronic devices fail
after 25 years... maybe sooner.
That would be bad for an airplane, OTOH airplanes are taken apart completely
quite often for maintenance, replacing micros after 10 years should be made
mandatory (but can you still get these).

Our here it isn't customary to take a whole airplane apart after 10
years. What is taken apart after 2000hrs or whatever their TBO rating
would be the engines.

Old Apollo spacecraft had core memory IIRC.

If it ain't broken why fix it? The design of the pump for the pool sweep
system I am restoring right now probably dates back to the 40's. Works fine.

But the mars Rovers have Xilinx FPGAs IIRC, lot of cosmic high energy rays....

But there aren't a few hundred people on board that could die if
something in the electronics croaks.

Have fun.

Actually, I am. Doing analog stuff is still fun. But not today. Got to
work the honey-do list, repairing some freeze damage (global warming, ha
ha). That's less fun than circuit design but someone's got to do it.
Then in the evening, barbeque time

--
Regards, Joerg

http://www.analogconsultants.com

 

[Jan Panteltje]

On a sunny day (Sat, 20 Jan 2007 20:37:07 GMT) it happened Joerg
<notthisjoergsch@removethispacbell.net> wrote in
<T3vsh.36327$Gr2.28275@newssvr21.news.prodigy.net>:

PIC 12F629 (8 pin DIL) is specified to work between 2V and 5.5 V.
It has an internal oscillator you can software calibrate, many more features.
And 1nA standby current.
The 12F675 also has a 10 bit AD.
I have used ten recently and so far no problems.
The 12F629 costs 0.67 $ in volume.
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1001&mid=10&lang=en&pageId=74

As you referred to 4060 I think this beats it every way, except price perhaps.
For things like prof equipment (like i nairplanes) the 67 cent x 2 cannot
possibly be a problem?


Add to that an LDO and low-ESR cap for 40c, comes to $1.74. I've got to
deal with a 4V to 9V range. Now the two 4060 chips plus two resistors
and one cap each add to a grand total of 35c, no LDO needed. Also, there
is only one LDO (TPS71xxx series) under 2.5uA and even that is a bit
painful in this app. Plus I had some not so good experiences with those.

The delays is all I need from them and the 4060 does this just fine.
Using a uC would have added NRE time and cost for the client while the
4060 just gets pulled from the CAD library and that's pretty much it.
Ok, I also need a reference here but a uC with that on board pops right
through the 80c barrier. Ye olde TLV431 for 8c or so will be fine.

This one isn't for an airplane but a semi-disposable and it is very
important to demonstrate the economic side of things. Two 67c micros
would freak everyone out

Even if it was for an airplane there is another side of this equation:
False alarm rate and stuff like that. Simplicity of your circuit is
rather essential and a uC doesn't exactly score that high. If you have a
solution that can live without code and with parts that can be backed up
with 30+ years of reliability data why not use it?

What could work would be two 4-bit micros as long as they are under 15c.

OK, but I do not see why 4 bit would be OK and 8 not.
One thing is very true, we do not know how long flash memory will last
(if I had to guarantee it), we will probably see many electronic devices fail
after 25 years... maybe sooner.
That would be bad for an airplane, OTOH airplanes are taken apart completely
quite often for maintenance, replacing micros after 10 years should be made
mandatory (but can you still get these).
Old Apollo spacecraft had core memory IIRC.
But the mars Rovers have Xilinx FPGAs IIRC, lot of cosmic high energy rays....
Have fun.

 

[Joerg]

Jan Panteltje wrote:

On a sunny day (Sat, 20 Jan 2007 18:00:48 GMT) it happened Joerg
notthisjoergsch@removethispacbell.net> wrote in
kNssh.2733$O02.1566@newssvr11.news.prodigy.net>:


Jan Panteltje wrote:


On a sunny day (Fri, 19 Jan 2007 20:48:27 GMT) it happened Joerg
notthisjoergsch@removethispacbell.net> wrote in
v8ash.2570$O02.2066@newssvr11.news.prodigy.net>:



Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete.


Maybe you do not like micro controllers, but long precise delays with micros
are much easier to make then with discrete or some logic.
I assume you have other reasons to dump the micro?
Else even the smallest PIC will give you years delay if must be.


I almost used a uC. Didn't for two reasons: uC don't have enough allowed
VCC range and LDO are notoriously unreliable IMHO (and expensive). 2nd,
I'd need two uC since both delays must be HW independent for safety
reasons. Like the navigation computers on large airplanes.


PIC 12F629 (8 pin DIL) is specified to work between 2V and 5.5 V.
It has an internal oscillator you can software calibrate, many more features.
And 1nA standby current.
The 12F675 also has a 10 bit AD.
I have used ten recently and so far no problems.
The 12F629 costs 0.67 $ in volume.
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1001&mid=10&lang=en&pageId=74

As you referred to 4060 I think this beats it every way, except price perhaps.
For things like prof equipment (like i nairplanes) the 67 cent x 2 cannot
possibly be a problem?

Add to that an LDO and low-ESR cap for 40c, comes to $1.74. I've got to
deal with a 4V to 9V range. Now the two 4060 chips plus two resistors
and one cap each add to a grand total of 35c, no LDO needed. Also, there
is only one LDO (TPS71xxx series) under 2.5uA and even that is a bit
painful in this app. Plus I had some not so good experiences with those.

The delays is all I need from them and the 4060 does this just fine.
Using a uC would have added NRE time and cost for the client while the
4060 just gets pulled from the CAD library and that's pretty much it.
Ok, I also need a reference here but a uC with that on board pops right
through the 80c barrier. Ye olde TLV431 for 8c or so will be fine.

This one isn't for an airplane but a semi-disposable and it is very
important to demonstrate the economic side of things. Two 67c micros
would freak everyone out

Even if it was for an airplane there is another side of this equation:
False alarm rate and stuff like that. Simplicity of your circuit is
rather essential and a uC doesn't exactly score that high. If you have a
solution that can live without code and with parts that can be backed up
with 30+ years of reliability data why not use it?

What could work would be two 4-bit micros as long as they are under 15c.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Jan Panteltje]

On a sunny day (Sat, 20 Jan 2007 18:00:48 GMT) it happened Joerg
<notthisjoergsch@removethispacbell.net> wrote in
<kNssh.2733$O02.1566@newssvr11.news.prodigy.net>:

Jan Panteltje wrote:

On a sunny day (Fri, 19 Jan 2007 20:48:27 GMT) it happened Joerg
notthisjoergsch@removethispacbell.net> wrote in
v8ash.2570$O02.2066@newssvr11.news.prodigy.net>:


Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete.


Maybe you do not like micro controllers, but long precise delays with micros
are much easier to make then with discrete or some logic.
I assume you have other reasons to dump the micro?
Else even the smallest PIC will give you years delay if must be.


I almost used a uC. Didn't for two reasons: uC don't have enough allowed
VCC range and LDO are notoriously unreliable IMHO (and expensive). 2nd,
I'd need two uC since both delays must be HW independent for safety
reasons. Like the navigation computers on large airplanes.

PIC 12F629 (8 pin DIL) is specified to work between 2V and 5.5 V.
It has an internal oscillator you can software calibrate, many more features.
And 1nA standby current.
The 12F675 also has a 10 bit AD.
I have used ten recently and so far no problems.
The 12F629 costs 0.67 $ in volume.
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1001&mid=10&lang=en&pageId=74

As you referred to 4060 I think this beats it every way, except price perhaps.
For things like prof equipment (like i nairplanes) the 67 cent x 2 cannot
possibly be a problem?

 

[Joerg]

Jan Panteltje wrote:

On a sunny day (Fri, 19 Jan 2007 20:48:27 GMT) it happened Joerg
notthisjoergsch@removethispacbell.net> wrote in
v8ash.2570$O02.2066@newssvr11.news.prodigy.net>:


Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete.


Maybe you do not like micro controllers, but long precise delays with micros
are much easier to make then with discrete or some logic.
I assume you have other reasons to dump the micro?
Else even the smallest PIC will give you years delay if must be.

I almost used a uC. Didn't for two reasons: uC don't have enough allowed
VCC range and LDO are notoriously unreliable IMHO (and expensive). 2nd,
I'd need two uC since both delays must be HW independent for safety
reasons. Like the navigation computers on large airplanes.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

Genome wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:1ufsh.68665$wP1.36056@newssvr14.news.prodigy.net...

Genome wrote:


"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:s9esh.62713$qO4.56356@newssvr13.news.prodigy.net...


Genome wrote:



"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:v8ash.2570$O02.2066@newssvr11.news.prodigy.net...



Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete. Need a couple long timers so I am looking at the old
CD4060, hoping to find some in TSSOP stock.

For 5V it states the frequency as 23kHz +/-10%. But the usual formula
is f=1/(2.2*Rx*Cx) and that comes to about 45kHz. I can't imagine these
things to have more than a few ten pF in internal capacitances so this
doesn't compute. Look at the 4th page (page 3-161):

http://focus.ti.com/lit/ds/symlink/cd4060b.pdf

Any ideas why?

--
Regards, Joerg

http://www.analogconsultants.com


I know you might not like NXP..... but, for me that was quite painless.


Oh, I like them. What I don't like is their marketing "effort" and IMHO
their web site is crummy. Their specsmanship was always superb though.




http://www.standardics.nxp.com/products/hef/pdf/hef4060b.pdf

Page 3-160) Figure 12) on the TI Dirty Sheet shows your equation for the
'oscillator' frequency.

Page 5) Figure 4) on the Philips/NXP Data Sheet gives a similar
equation. They also give other useful information........ I like Philips
and Siemens for Data Sheets....

Anyway,

The 'Logic' diagram on the Philips Data Sheet, Page 3) Figure 3) might
make more sense. Notice that there are four flop flips before you get to
O3. Flop Flip 1 divides the 'oscillator' frequency by two before the
rest of the stuff sees it.


One has to be really, really careful with that stuff. For example Moto/ON
often calls the first output Q4 while others call it Q3. That can really
throw people a curve when they discover that after the layout is done. We
used to have an "anger pad" for such situations. It hung on a wall and
read: In case of an upcoming temper trantrum take one sheet, crumple and
throw into a corner.




The TI Dirty Sheet is referring to a Clock Signal after Flop Flip 1.
Fair enough, the Philips Data Sheet might not specifically make that
point but the TI/Harris logic diagram hides it deeper.

Of course if I knew fuck about logic I would have been able to work it
out from the TI Dirty Sheet. But I don't.......

However, having looked at the two.... the TI Dirty Shit might show Flop
Flip 1 connected as a Toggle (JK with inverted inputs which could be a
D-type) before the rest of the counters get to see it.


They are basically all used as deviders feeding each other. Not the most
modern concept but for a slow timer it's often good enough.

--
Regards, Joerg

http://www.analogconsultants.com


Oh, alright then.

You asked..... the difference between about 45KHz and about 23KHz is
about a factor of two. It's quite possible that 2 is a digital divide by
two so..........


Ah, that's what you meant. Could, of course, be but what puzzled me was
the mention of both on the same datasheet. And they mentioned the
oscillator (sans dividers).



You absolute old patronising bastard you!

Your job interviews must last at least four hours whilst you blither on
about the good old days and a few terminal 'war stories'. Then, having
bored yourself, you'll forget my name as you ask your secretary to dial
me a taxi.


Actually, they could last an hour but I asked the people about their
stories. Mine I told later after I hired them ))



Assuming I get through that load of shit and get the job you might just
give me a broken chair and back order a customised bercostat for delivery
about the time your Ronny James manages to lock you up a cupboard so they
can sort out the power supply pins on an LM324.

Your design reviews will be three hours of nodding at your extreme
ability to focus on where to place potentiostat1 on the PCB with a
screaming desire to get out, ignore your input and get the job sorted.

Then you'll probably visit three times a day to ask if any of the
resistors are a slight shade of blue because something went wrong when
you used blue resistors in 1965.


Nah, that was ten years later and what happened was that RF turned a
capacitor from white ceramic into green glass. It was amazing.

So, dinner time and then I'll pour us a cold one...

--
Regards, Joerg

http://www.analogconsultants.com



OK. So where did I go wrong?

You didn't. T'was me, I must have misunderstood.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Ancient_Hacker]

Joerg wrote:

Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete. Need a couple long timers so I am looking at the old
CD4060, hoping to find some in TSSOP stock.

For 5V it states the frequency as 23kHz +/-10%. But the usual formula is
f=1/(2.2*Rx*Cx) and that comes to about 45kHz.

Either there is dividing by two, or it uses the RC ramp on both the
charge and discharge parts of the cycle..

 

[Eeyore]

Joerg wrote:

Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete. Need a couple long timers so I am looking at the old
CD4060, hoping to find some in TSSOP stock.

For 5V it states the frequency as 23kHz +/-10%. But the usual formula is
f=1/(2.2*Rx*Cx) and that comes to about 45kHz. I can't imagine these
things to have more than a few ten pF in internal capacitances so this
doesn't compute. Look at the 4th page (page 3-161):

http://focus.ti.com/lit/ds/symlink/cd4060b.pdf

Any ideas why?

2:1 out.

Some SMPS controllers have a similar idea of 'frequency' IIRC.

In the above I think they means " frequency of output voltage *changes* ".

Graham

Graham

 

[Jan Panteltje]

On a sunny day (Fri, 19 Jan 2007 20:48:27 GMT) it happened Joerg
<notthisjoergsch@removethispacbell.net> wrote in
<v8ash.2570$O02.2066@newssvr11.news.prodigy.net>:

Ok, guys, another case where I have to ditch the uC idea and go
semi-discrete.

Maybe you do not like micro controllers, but long precise delays with micros
are much easier to make then with discrete or some logic.
I assume you have other reasons to dump the micro?
Else even the smallest PIC will give you years delay if must be.

 

[Joerg]

colin wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:3o5ah.315$Py2.32@newssvr27.news.prodigy.net...

can you compensate by monitoring the laser diode output noise ?
or is the laser diode miles away ?
or maybe cancel it out with feedback ?


Yes, we could, but only in the final design. I am already seeing it
coming that I have to regulate out at least some of the noise. Not
looking forward to that because it has to be done up to 100MHz plus that
still doesn't take care of the phase noise part. The latter would
require some nifty optical detector (getting stomach cramps here...).


Good luck ! and dont forget to breath.

Would you digitise the full 100Mhz ?
Wonder if the sampling units in such scopes are easily available.

Yes, but it won't be a scope. It's going to be our own design. Scope
don't show a lot of ENOBs up there, maybe 6-7. We need a lot more.

Is there any structure to the signal and difference ?
Ie is the full bandwidth used all the time so it just looks like white noise
?
or are there periodic repetitions etc ?

All the time.

Is the difference in light signal due to the changes in
reflection/refraction/absorbtion ?

Basically all reflection.

Ive been looking for an elusive ~1ps variation in delay for some time now on
and off with little success so far.

Well, we'll be looking at femtometers ;-)

--
Regards, Joerg

http://www.analogconsultants.com

 

[colin]

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:3o5ah.315$Py2.32@newssvr27.news.prodigy.net...

can you compensate by monitoring the laser diode output noise ?
or is the laser diode miles away ?
or maybe cancel it out with feedback ?


Yes, we could, but only in the final design. I am already seeing it
coming that I have to regulate out at least some of the noise. Not
looking forward to that because it has to be done up to 100MHz plus that
still doesn't take care of the phase noise part. The latter would
require some nifty optical detector (getting stomach cramps here...).

Good luck ! and dont forget to breath.

Would you digitise the full 100Mhz ?
Wonder if the sampling units in such scopes are easily available.

Is there any structure to the signal and difference ?
Ie is the full bandwidth used all the time so it just looks like white noise
?
or are there periodic repetitions etc ?
Is the difference in light signal due to the changes in
reflection/refraction/absorbtion ?

Ive been looking for an elusive ~1ps variation in delay for some time now on
and off with little success so far.

Colin =^.^=

 

[Joerg]

colin wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:68%9h.9712$6t.927@newssvr11.news.prodigy.com...

Hello Colin,

Im not sure what the shot noise from the detector would be,
but although your signal is dc-100mhz what is the bandwitdh of the

change?

It's almost the whole range :-(

The dark current noise typically wins AFAICT. The last calcs had the
shot noise almost a order of magnitude above everything else. That's for
the photo diode. Thing is, the RIN for the laser diode doesn't mean much
for us because this app is also sensitive to phase noise. All they give
you in the datasheet is spectral line width and who knows what's
underneath that number. Mode jumps etc.


can you compensate by monitoring the laser diode output noise ?
or is the laser diode miles away ?
or maybe cancel it out with feedback ?

Yes, we could, but only in the final design. I am already seeing it
coming that I have to regulate out at least some of the noise. Not
looking forward to that because it has to be done up to 100MHz plus that
still doesn't take care of the phase noise part. The latter would
require some nifty optical detector (getting stomach cramps here...).

--
Regards, Joerg

http://www.analogconsultants.com

 

[colin]

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:68%9h.9712$6t.927@newssvr11.news.prodigy.com...

Hello Colin,
Im not sure what the shot noise from the detector would be,
but although your signal is dc-100mhz what is the bandwitdh of the
change?


It's almost the whole range :-(

The dark current noise typically wins AFAICT. The last calcs had the
shot noise almost a order of magnitude above everything else. That's for
the photo diode. Thing is, the RIN for the laser diode doesn't mean much
for us because this app is also sensitive to phase noise. All they give
you in the datasheet is spectral line width and who knows what's
underneath that number. Mode jumps etc.

can you compensate by monitoring the laser diode output noise ?
or is the laser diode miles away ?
or maybe cancel it out with feedback ?

Colin =^.^=

 

[Rich Grise]

On Thu, 25 Jan 2007 18:42:46 +0000, Lostgallifreyan wrote:

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in

A few more years, and it will be illegal to
even breathe in Europe.

No, no... they'll just tax us to death for doing it, or make it pay-per
litre and the poor will just have to suffocate for non-payment. I see your
point though.

If a standards change has no clear grounding in engineering, why not just
ignore it? In the end they'll adopt your standards because it's the only
stable thing they can grasp.

http://home.att.net/~chuckayoub/Taxman_Lyrics.html

Good Luck!
Rich

 

[qrk]

On Tue, 23 Jan 2007 17:15:31 -0800, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

It's bewildering. Was looking for diodes in SC-75, barely anything. Then
by chance I found the beloved old BAS, BAV and BAT diodes again.
Slightly different numbers but they were listed under SOT-523 which
looks the same to me as SC-75, or SOT-416 for that matter.

Is there a somewhat official site that has a compatibility table like
the ones for watch batteries?

This site has a free program with lots of SMT stuff.
http://www.pcblibraries.com/
Look on the right side of the web page for the download.

Gives part size and PCB footprint info. Problem is finding which
package name they list (is it SOT323 or SC70???). For ICs, knowing the
JDEC MOxxx works best in this program.

---
Mark

 

[Lostgallifreyan]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in
news:45B7E420.3C8EF3C3@earthlink.net:

A few more years, and it will be illegal to
even breathe in Europe.

No, no... they'll just tax us to death for doing it, or make it pay-per
litre and the poor will just have to suffocate for non-payment. I see your
point though.

If a standards change has no clear grounding in engineering, why not just
ignore it? In the end they'll adopt your standards because it's the only
stable thing they can grasp.

 

[Michael A. Terrell]

Joerg wrote:

A typical example of the nonsense that a bloated bureaucracy comes up
with. Unfortunately that will lead to confusion with, among other
things, SMT. A 0402 cap is now also a 1005. What will definitely lead to
layout errors is that Eurocrats call the 0201 size "0603". Pretty stupid
IMHO.

Actually, its brilliant! Its one more step towards them not being
able to do anything right. A few more years, and it will be illegal to
even breathe in Europe. After all the idiots suffocate we can sit back
and laugh.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida