audio recording on IC -help wanted

[JeffM]

was: FS: Lots of books, parts, kits

Ed wrote:

I have added additional 'For Sale' items to my web site

Legitmate businessmen know that advertising is a cost of business
just like rent and utilities.

Legitmate businessmen
honor the charters of the groups to which they post:
http://groups.google.com/group/sci.electronics/msg/13651a897337a7a9?q=Charters+misc.industry.electronics.marketplace+Discussions+Advertisement-*-*+only-advertise+sci.electronics.components-Integrated-*-*-*+zz-zz+qq-qq+uu+Discussion

 

[Eeyore]

ivan wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> ha scritto nel messaggio

It proves absolutely nothing of the sort.

You're barking up the wrong tree.

well... I have R=22, L=737uH and C=2,2nF so Q is about 26.3.

You mean C=2.20 nF ?

What happens when C = 2.22 nF or 2.18 nF ? The resonant frequency will shift and
the current and voltage will no longer 'peak' in the same way as with 2.20 nF (
assuming it's set up for that exactly ).

Bear in mind that the average L can't be trusted to be 737.00 uH either btw !

With a Q of ~ 26 you most certainly aren't looking at capacitor dielectric loss
issues.

You should do as another poster suggested and add a small trimmer cap in
parallel with your C and tune for resonance. That may open your eyes as to
what's going on.

Graham

 

[ivan]

"John Fields" <jfields@austininstruments.com> ha scritto nel messaggio
news:tidtq25psph084lktd1nijm8mpnjuba9os@4ax.com...

On Wed, 17 Jan 2007 18:40:39 +0100, "ivan" <tecnico@wolfsafety.it
wrote:


I have short circuited R and saw an increase of 15Vpp. By changing the
cap
type I see from worst (50Vpp) to best (120Vpp). Would ESR variance be
high
enough? What are the typical values of ESR? Unfortunately I do not have
the
means to do a proper study on this here...

---
Earlier you stated that your circuit looked something like this:
(View in Courier)

Er
/
+----[7.37E-4H]--+--[2.2E-9F]--+--[22R]----+
| |
[GEN1] [GEN2]
| |
GND GND


Where GEN1 and GEN2 are square-wave sources with their outputs 180
degrees out of phase and Er is the voltage measured, to ground, from
the junction of the capacitor and the resistor.

From the values you've given, the circuit is resonant at:

1 1
f = -------------- = ------------------------------------
2pi sqrt(LC) 6.28 * sqrt (7.37E-4H) * (2.2E-9F)


~ 125kHz.


and the reactances of the capacitor and inductor will be:


Xc = Xl = 2pi fL = 6.28 * 1.25E5Hz * 7.37E-4H ~ 578 ohms


Now, since the signs of the reactances are opposite to each other,
at resonance they'll cancel and you'll be left with only the
resistance of the 22 ohm resistor, the resistance of the wire in the
inductor and the equivalent series resistance (ESR) of the capacitor
to limit the current through the circuit. Just for grins, if we
assume an ohm for each, the total series resistance in the circuit
will be 24 ohms.

Now, in order to determine the current in the circuit we'll need to
determine its impedance, thus:


Z = sqrt (R˛ + (Xl - Xc)˛)


= sqrt (24˛ + (578 - 578)˛)


= 24 ohms


Assuming you're driving your circuit with 5V sources, the maximum
current you'll be able to pump through the 24 ohms will be:

E 5V
I = --- = ----- = 0.208 ampere
R 24R

but because the reactance of the capacitor is 578 ohms, the voltage
dropped across it will be a startling:


E = IR = 0.208A * 578R ~ 120V

ok I understand, It looks like this capacitor has a 2R series resistance
then.
and the other which swings at 80V has a series resistance of 14.125R as:

80V / 578R ~ 0.138A

5V / 0.138A = 36.125R

36.125R - 22R = 14.125R

yeah I see what you are saying now...

Now, assuming that your generators can deliver the current and you
short out the 22 ohm resistor, the reactances will still cancel and
we'll be left with 2 ohms of resistance to oppose the current. That
means the current in the circuit will be:

E 5V
I = --- = ---- = 2.5 ampere
R 2R

and since the reactances haven't changed, the voltage dropped across
the capacitor will be:


E = IR = 2.5A * 578R = 1445V.

I get about 160Vpp here actually...

for those who asked, the complete circuit is roughly as shown at
http://www.atmel.com/dyn/resources/prod_documents/doc4684.pdf
in Figure 4-1. The signal and the resonant branch I refer to are COIL1 and
COIL2...

So, it looks like just shorting out the resistor will get you a
voltage increase of:


1445
------ = 12 = 1200%
120

There are also some second order effects like the inductance of the
inductor changing as the current (and frequency) through it changes,
and the parametric effects of dielectrics causing capacitance change
with voltage which will spoil resonance.

Of course there are always the primary effects, which in your case
involve the capacitance tolerances of the capacitors you're using
and their ESR's (losses) which could easily explain the results
you've been getting.


Here's an LTSPICE circuit list of your circuit which you may find
interesting:

ok I'll try this...thanks!

Version 4
SHEET 1 880 680
WIRE -288 144 -352 144
WIRE -160 144 -208 144
WIRE -48 144 -96 144
WIRE 80 144 32 144
WIRE -352 240 -352 144
WIRE 80 240 80 144
WIRE -352 384 -352 320
WIRE 80 384 80 320
WIRE 80 384 -352 384
WIRE -352 416 -352 384
FLAG -352 416 0
SYMBOL res 48 128 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R1
SYMATTR Value 22
SYMBOL cap -96 128 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C1
SYMATTR Value 2.2e-9
SYMATTR SpiceLine Rser=1
SYMBOL ind -304 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName L1
SYMATTR Value 737e-6
SYMATTR SpiceLine Rser=1
SYMBOL voltage -352 224 R0
WINDOW 3 24 44 Invisible 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 5 0 0 0 3.998e-6 7.996e-6)
SYMBOL voltage 80 224 R0
WINDOW 3 24 104 Invisible 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value PULSE(5 0 0 0 0 3.998e-6 7.996e-6)
TEXT -386 506 Left 0 !.tran 1e-3 uic


If you don't have LTSPICE you can download it, free, from Linear
Technology's web site. Sorry, I can't get the link right now.


--
JF

 

[ivan]

"Ancient_Hacker" <grg2@comcast.net> ha scritto nel messaggio
news:1169123516.813514.51800@q2g2000cwa.googlegroups.com...

Eeyore wrote:


Firstly you need to match the caps to better than +/- 1% to avoid
capacitance
value being a contributing factor.

Graham

AND he better tell us what kind of cap meter he's using. Many $4.99
DVM's from the corner gas station have a cap measuring feature, but
they are actually measuring how quickly it oscillates in a RC
oscillator. Said frequency is only vaguely related to the actual
capacitance, especially for lossy or leaky capacitors.

it is a fluke 185, it has three digits after comma when measuring nF...

 

[Homer J Simpson]

"George C." <harley.davidson@mailcity.com> wrote in message
news:45b37146.9818383@news.west.earthlink.net...

I can't get Ohm's law, because I always end up asking myself "Ok, so
what's the point?"

The point is that for most metals the function V/I is approximately linear
over normal temperature ranges. Contemplate what would happen if it was a
reciprocal or squared function.






--








--

 

[Tim Shoppa]

doc@sympatico.ca wrote:

While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

The guts of the batteries will be highly corrosive to any metal they
landed on. Just the vapor can wreck PC board traces given enough time.
A mild acid (vinegar has acetic acid) may help remove any corrosion
that has already taken place, after using the acid you then have to
neutralize/wash down to remove the acid. It's like the old lady that
swallowed the fly...

Tim.

 

Thanks for the suggestions.

Someone in another group suggested that I follow the manufacturer's
instructions for charging.

FWIW, this happened because I was doing a fast charge.
I'm usually very careful to stop the process as soon as there
is any heat.

But this time I got called to dinner when I should have been
watching the stew. Actually more like pop-corn!

On a more serious note, I am reminded about how familiarity breeds
contempt and can often lead to compromising safety.

Anyway, cleaned up the mess. No real harm seems to have been
done except I prolly blew up about $60.00 worth of nicad cells.


DOC
Have robots. Will travel. http://www.robot-one.ca

Tim Shoppa wrote:

doc@sympatico.ca wrote:
While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

The guts of the batteries will be highly corrosive to any metal they
landed on. Just the vapor can wreck PC board traces given enough time.
A mild acid (vinegar has acetic acid) may help remove any corrosion
that has already taken place, after using the acid you then have to
neutralize/wash down to remove the acid. It's like the old lady that
swallowed the fly...

Tim.

 

i just exploded a NIMH camcorder 3.2 volt can.

i thought ok, i'll just connect this to my lowly wall wart for about 15
minutes. as usual i forgot about it. 1 hr later i hear this hissing high
pressure gass sound, then KABOOOM! and i mean KABOOM! i was louder than an
M80, and inside the house it seemed like an artillery shell had gone off.
then i set about extinguishing the shards of plastic/copper foil and
chemcal fires scattered around the room. very nasty indeed! can had
propelled itself from the tabletop nearly through a sheetrock wall, then
rebounded around a bit.

next time i do it outside , inside a metal fireproof trash container!

then again, the correct charger would avoid all this.

<doc@sympatico.ca> wrote in message
news:1169485409.367021.230100@l53g2000cwa.googlegroups.com...

Thanks for the suggestions.

Someone in another group suggested that I follow the manufacturer's
instructions for charging.

FWIW, this happened because I was doing a fast charge.
I'm usually very careful to stop the process as soon as there
is any heat.

But this time I got called to dinner when I should have been
watching the stew. Actually more like pop-corn!

On a more serious note, I am reminded about how familiarity breeds
contempt and can often lead to compromising safety.

Anyway, cleaned up the mess. No real harm seems to have been
done except I prolly blew up about $60.00 worth of nicad cells.


DOC
Have robots. Will travel. http://www.robot-one.ca

Tim Shoppa wrote:
doc@sympatico.ca wrote:
While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

The guts of the batteries will be highly corrosive to any metal they
landed on. Just the vapor can wreck PC board traces given enough time.
A mild acid (vinegar has acetic acid) may help remove any corrosion
that has already taken place, after using the acid you then have to
neutralize/wash down to remove the acid. It's like the old lady that
swallowed the fly...

Tim.

 

[Joerg]

Rich Grise wrote:

On Tue, 23 Jan 2007 17:15:31 -0800, Joerg 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?


I don't know if there's anything "official", but just for S&G I did:

http://www.google.com/search?q=surface-mount+component+package+outline+drawings

and got "about 98,300" hits.

Some of them look promising, especially if you know what you're looking
for. I didn't see a(an?) "SC-75", but we don't do other people's homework
here anyway. ;-)

I got plenty of hits as well but also some contradictory pages. I was
looking for a listing that is somewhat official. When I find one I'll
post it.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

Al wrote:

In article <_oyth.20795$ZT3.16867@newssvr19.news.prodigy.com>,
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?


At one time military standards made devices compatible. But since they
were dropped in favor of OTS, chaos.

Yes, the military has always been an order of magnitude better in
standardization than any civilian group. The worst ought to be EDA. Lip
service, EDIF meetings, press releases, lots of blah-blah and the result
is total chaos. No idea why because in medical we managed to agree on
one standard (DICOM) and it works. Despite the fact that the number of
competitors was a whole lot larger.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Tim Wescott]

Joerg 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?

There's a business opportunity here for the enterprising component

engineer or layout guy:

Make the web site, slather the borders* with click-through ads for
semiconductor companies, PCB houses, layout software, etc. Then keep it
up to date so that everyone goes there.

It could, if it were good enough, pay for itself.

Particularly if it had a nice table of equivalents, plus some
recommended pad patterns for various different PCB layout software versions.

* Border ads don't bother me. Pop-ups make me want to shoot someone,
but border ads are OK.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html

 

[Joerg]

Rene Tschaggelar wrote:

Joerg 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?


Joerg,
I came to tag new cases used in a layout with the manufacturer
and its internal reference number. I doubt there is an official
compatibility table. While some cases may look identical, their
recommended footprint, if there is any, may not be identical.

That's always been different even for the very same sizes, I got used to
that. But it used to be that SOT23 was SOT23 was SOT23. Now they have
three or more designators for the same package. Makes no sense.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

John Larkin wrote:

On Tue, 23 Jan 2007 19:45:23 GMT, Joerg
notthisjoergsch@removethispacbell.net> wrote:


John Larkin wrote:


On Tue, 23 Jan 2007 18:59:42 GMT, Joerg
notthisjoergsch@removethispacbell.net> wrote:



John Larkin wrote:



Always do it this way,




3
=====
1 2


and ignore the mfr's convention. That's what we do with SOT-23's


Yep, guess that's what I'll do. Then frame it and give it to my
layouter. Maybe we could start an "s.e.d. convention on pinouts"...


It was, and still is, a gross error to make IC packages rotationally
symmetric. You couldn't plug a tube in wrong.


Yes, I never understood that either. Seems the semi industry is not very
competent when it comes to package and pinout standardizations. And it's
not rocket science. In medical we and most other companies had sent a SW
engineer to the DICOM meetings on a regular basis and now we all have
one common standard. When there is a noise problem I can run the pics
and video loops from pretty much any system right here in the lab, don't
even have to travel.


Today we had a delay generator board that would start up run for a
couple of seconds, then reset itself and do it again. We scoped it
with our FLIR thermal imager and one of the US8 logic gates was
blazing like a tiny comet just before shutdown. It was in backwards.

Man, you guys are high-tech. Usually this stuff is done by moving the
back of the hand over the board, touching a few chips with the finger
tips and when a yelping emerges from the mouth of the tester the culprit
is found. After that it's looking where the burn gel is.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Al]

In article <_oyth.20795$ZT3.16867@newssvr19.news.prodigy.com>,
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?

At one time military standards made devices compatible. But since they
were dropped in favor of OTS, chaos.

Al

 

[John Fields]

On Sun, 21 Jan 2007 01:12:01 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Fields wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
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.

---
And they won, huh?

Those fighters are damn good.

---
Well, no shit Sherlock?


--
JF

 

[Lostgallifreyan]

Boris Mohar <borism_-void-_@sympatico.ca> wrote in
news:fvp6r2d010fb4g3jisnfnkaip83nh3esgd@4ax.com:

A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

Nice.

 

[Boris Mohar]

On Mon, 15 Jan 2007 10:30:30 +1300, "Frank" <erty@home.com> wrote:

I have to ask you "were have you started to read this message"
AT THE TOP OF THE PAGE

So why the fuck do bottom posting wankers want you to spend time scrolling
down a page of crap looking for were the new message starts ? because they
are thick, OK you might ask, why not remove the old message so the new
message appears at the top of the page, well that is one option, I only
include it so anyone who comes in half way down the thread can work out what
is go on, how often does that happen, Not very often.

Get a life, stop wanking, stop bottom posting. Top posting saves time, as us
more intelligent people seem to understand.

A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

--

Boris Mohar

 

[John Fields]

On Sat, 20 Jan 2007 23:30:13 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

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.

---
And they won, huh?


--
JF

 

[Eeyore]

John Fields wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
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.

---
And they won, huh?

Those fighters are damn good.

Graham

 

[Henry Kiefer]

"Terry Given" <my_name@ieee.org> schrieb im Newsbeitrag news:1169334614.667521@ftpsrv1...
| AIUI the US military wants new air frames designed for 100year lives.

With or w/o missile attacks included?

- Henry


--
www.ehydra.dyndns.info