audio recording on IC -help wanted

[Hal Murray]

32.768 kHz is 2^15 Hz

Where does 3.579545 MHz come from?

TV color burst.

--
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[Charlie Edmondson]

Robert wrote:

Don Lancaster <don@tinaja.com> wrote in
news:4s1bc3Fthjr8U1@mid.individual.net:


Don Lancaster wrote:

la-la wrote:


Hi,

how to make a crystal /ceramic oscilator for a specicfied frequency
in kHz range ?
Is it posssible to make one on myself, or find someone to make it ?
What is a minimum order quantity for a crystal/c eramic resonator
for a specified frequency (kHz) ?
Please help me.


We have many tens of thousands of crystal oscillator modules in stock
at fifty cents each.

Our lowest frequencies are 28.8 kHz, 108 kHz, 153.6 kHz, 250 kHz, 256
kHz, 307.2 kHz, 326.4 kHz plus hundreds of higher frequencies.

In general, it is usually cheaper and simpler to use a higher
frequency and a CMOS binary divider.

Also in general, if your system does not use a crystal frequency of
32.768 kHz or 3.59545 MHz, you should flush it and start over.




Oops.

Should be 3.579545 of course.




32.768 kHz is 2^15 Hz

Where does 3.579545 MHz come from?


Color burst frequence in NTSC signals...

Charlie

 

[Tom Bruhns]

Robert wrote:

32.768 kHz is 2^15 Hz

Where does 3.579545 MHz come from?

The colour subcarrier of NTSC-encoded colour television broadcasts.
The crystals, being very common at least in the USA, are cheap. FWIW,
the NTSC colour subcarrier is nominally at 63/176 times 10MHz (with a
tolerance of +/-10Hz; usually kept much closer to the nominal than the
tolerance would allow), the horizontal scan frequency is 2/455 times
the colour subcarrier frequency, and the vertical scan frequency is
2/525 times the horizontal scan frequency. Expect that the scan
frequency ratios to the colour subcarrier will be exact at least in any
broadcast signal, to get proper interlace.

There are other "inexpensive" crystal frequencies. Low kHz
frequencies, of course, are not among them, but accurate generation of
low kHz frequencies is possible through division from higher crystal
frequencies.

Cheers,
Tom

 

[Joel Kolstad]

"Robert" <someone@nowhere.com> wrote in message
news:xrL6h.2472$yE6.1776@newssvr14.news.prodigy.com...

Where does 3.579545 MHz come from?

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

 

[Joel Kolstad]

"Robert" <someone@nowhere.com> wrote in message
news:xrL6h.2472$yE6.1776@newssvr14.news.prodigy.com...

Where does 3.579545 MHz come from?

More information on exactly why 3.579545MHz was chosen:
http://en.wikipedia.org/wiki/NTSC (see the "color encoding" section)

 

[Rich Grise]

On Wed, 15 Nov 2006 14:33:07 -0800, Joel Kolstad wrote:

"Robert" <someone@nowhere.com> wrote in message
news:xrL6h.2472$yE6.1776@newssvr14.news.prodigy.com...
Where does 3.579545 MHz come from?

More information on exactly why 3.579545MHz was chosen:
http://en.wikipedia.org/wiki/NTSC (see the "color encoding" section)

Ah, HA! At last!
"The remaining vertical blanking interval lines are typically used for
datacasting or ancillary data such as video editing timestamps (vertical
interval timecodes or SMPTE timecodes on lines 12-14 [3] [4]), test data
on lines 17-18, a network source code on line 20 and closed captioning,
XDS and V-chip data on line 21. Early teletext applications also used
vertical blanking interval lines 14-18 and 20, but teletext over NTSC was
never widely adopted by viewers [5]."

Anyone for a commercial skipper? I think I might hack into my TeeVee, and
sync up line 20 and see if there's any predictable change when they go
to commercial. "Network source code"? Sounds fascinating!

I wonder where I'd look up the coding protocol?

Cheers!
Rich

 

[Boris Mohar]

On Wed, 15 Nov 2006 16:52:34 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello Robert,


Is there an n-channel FET that can stomach 180V or more yet switch in
nanoseconds? I am looking for around 3-4 nsec or less for rise time,
fall time, toff delay and ton delay. The Zetex ZXMN10 does that nicely
but it's only 100V.

What about the BSS131 by Infineon? rather small die size, rated to
240V and N-channel SOT-23 package).


It has poor tdoff and tf (>>10nsec), plus we'd need to parallel about
ten of them which drives the capacitances to uncomfortable levels.
Infineon does have some newer nice devices but I am a bit hesitant with
that manufacturer after they weren't able to get samples of their BSP297
to us. Despite the fact that I told them we'd pay whatever it takes to
get them across the ocean and almost two hours on the phone :-(

When I was working on ground penetrating radar we discovered several things
most of which are still true today. The on and off times are as per test
circuit and not absolute limits of the device. Many devices could sustain
larger than specified gate voltage overdrive. Caveat here, our duty cycle was
low. Often unspecified Internal Source Inductance was the unwelcome wall.

--

Boris Mohar



--
Posted via a free Usenet account from http://www.teranews.com

 

[Gerald Bonnstetter]

Robert wrote:

Don Lancaster <don@tinaja.com> wrote in
news:4s1bc3Fthjr8U1@mid.individual.net:

Don Lancaster wrote:
la-la wrote:

Hi,

how to make a crystal /ceramic oscilator for a specicfied frequency
in kHz range ?
Is it posssible to make one on myself, or find someone to make it ?
What is a minimum order quantity for a crystal/c eramic resonator
for a specified frequency (kHz) ?
Please help me.

We have many tens of thousands of crystal oscillator modules in stock
at fifty cents each.

Our lowest frequencies are 28.8 kHz, 108 kHz, 153.6 kHz, 250 kHz, 256
kHz, 307.2 kHz, 326.4 kHz plus hundreds of higher frequencies.

In general, it is usually cheaper and simpler to use a higher
frequency and a CMOS binary divider.

Also in general, if your system does not use a crystal frequency of
32.768 kHz or 3.59545 MHz, you should flush it and start over.



Oops.

Should be 3.579545 of course.



32.768 kHz is 2^15 Hz

Where does 3.579545 MHz come from?

US TV color burst frequency. There is one crystal of that frequency in
every US TV. So they are very common and cheap.

Not sure how long that will stay after HDTV takes over. I would think
it would still be needed for S-video and lower quality inputs from
legacy DVD's and VCRs.


--

Gerald Bonnstetter
Bonnsoft - Computer Programming and Software Repair
Ventura, Iowa, USA
bonnsoft@netins.net
http://showcase.netins.net/web/bonnsoft/

 

[Ross Herbert]

On Sat, 11 Nov 2006 15:44:22 -0800, Winston <Winston@BigBrother.net>
wrote:

Hello everybody,

I'm in Silicon Valley, California, USA and I'm developing a product that
must mate to an existing assembly. I seek about 100 pieces each of
these Tyco/AMP/Aces parts within the next 30 days:

1-5316560-1
1-5353187-1

They are 0,6 mm center distance 160 pin SMT board - to - board connectors.

All three vendors I contacted want reasonable money for these parts, but
require 3500 - piece minimum purchases for each part number. I *could*
buy them but that would blow the budget for the rest of the parts I need.

'Other vendors' have quoted full retail price with doubled lead times!

I found that eBay.com digikey.com, alliedelect.com or radioshack.com
cannot sell me these.

Can you recommend a good source that can sell me prototype quantities of
these parts?

Thanks!


-- Winston

Winston,

I have been trying to locate those part numbers on the Tyco website
without any joy.

The closest I can find are;
http://catalog.tycoelectronics.com/TE/bin/TE.Connect?S=23810&P=88074,2383,76450&M=PPROP&BML=10576,16358,17560,17540,17739&LG=1&I=13&N=1&IDS=60047
and
http://catalog.tycoelectronics.com/TE/bin/TE.Connect?S=23810&P=88074,2383,76450&M=PPROP&BML=10576,16358,17560,17540,17739&LG=1&I=13&N=1&IDS=76937

Are these the items you require? These part no's don't have the '5'
after the leading 1- as in your specification. It might make a
difference....

 

[Winston]

Ross Herbert wrote:

Winston,

I have been trying to locate those part numbers on the Tyco website
without any joy.

The closest I can find are;
http://catalog.tycoelectronics.com/TE/bin/TE.Connect?S=23810&P=88074,2383,76450&M=PPROP&BML=10576,16358,17560,17540,17739&LG=1&I=13&N=1&IDS=60047
and
http://catalog.tycoelectronics.com/TE/bin/TE.Connect?S=23810&P=88074,2383,76450&M=PPROP&BML=10576,16358,17560,17540,17739&LG=1&I=13&N=1&IDS=76937

Are these the items you require? These part no's don't have the '5'
after the leading 1- as in your specification. It might make a
difference....

That's them, Ross.

Tyco changed their part numbering system recently to include a leading
'5', but parts without the leading '5', in this case, are the same as
those with the '5'.

Thanks!

--Winston

 

[Homer J Simpson]

"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message
news:20061117.1622.322331snz@pcserviceselectronics.co.uk...

Well I am currently at about 28 hours (or more).

As they expect everybody to use their webforms if the web forms are
not working nothing gets through.

Sometimes Google can find a 'back entrance' for you.

 

[PolyVinalDistillate]

Hey there.

I have also aquired a couple of HP printers with the very same sensors.
One (Q9864) is used for the striped strip running behind the print-head

for position sensing, while the other (Q9845) is used in a similar
fasion
for a similarly encoded disk to gauge the paper position by the
rotation
of the rollers. I intend to use them for positioning in a CAD system,
and have also been looking for datasheets without success.

I have decided that I will figure them out datasheet or not, as they're

too useful looking to be sat around doing nothing! I'll happily tell
you
what I learn if your still looking for information when I've done some
fiddling about with the oscilloscope. So far I've only had a visual
inspection of the components and contemplated their use. I'm fairly
sure of the power connections from this first investigation, but can
only
guess at the function of the other two pins! I'd like to think one
pulsed
for left movement and the other for right... but that may be too much
to
hope! Perhaps it's more along the lines of the sensor system in a
mouse, where extra circuitry is required to decode direction from the
order of the beam interruption.

I have to show my ignorance and admit I have no idea what a
'quadrature' direction decoder is But I assume it's effectively a
device
that provides ready-decoded left and right outputs. Or perhaps it has
some bearing on sensitivity??

so far what I have is:


_________
| | 1: -ve
| | 2: ?
| | 3: +ve
---------- --------- 4: ?
|___________________|
| | | |
1 2 3 4

Not sure of the voltage, but I'd guess 5v *crosses fingers*

Please let me know if you've got more information than this!

Thanks

 

[Lostgallifreyan]

"PolyVinalDistillate" <PolyVinalDistillate@yahoo.co.uk> wrote in
news:1163822188.188994.188320@e3g2000cwe.googlegroups.com:

I have to show my ignorance and admit I have no idea what a
'quadrature' direction decoder is But I assume it's effectively a
device
that provides ready-decoded left and right outputs.

You got it. It's not entirely ready as a simple one-bit flag might be for
direction, but that's what it does. Not sure about this actual part, but it
probably is one. Two sensors, placed so that slots making a 50% duty cycle
will place a leading edge on one sensor when the second sensor is still 25%
behind, hence quadrature, a phase shift of a quarter cycle. A circuit can
test which sensor is trailing, regardless of speed, and get direction from
that.

 

[PolyVinalDistillate]

Of course I should've guessed that's where the quadrature came from!
*thinks back to his degree... QPSK and the like* Cheers for that

It could well be one of those, but the strip passing between the source
and the sensor is encoded somewhere in the order of 1/4 to 1/2 mm, so
it would need some fairly fancy optics within... The sensor is simply a
chunk of silicon around 3mm square under a protective plastic cover.
Looking at it now, it seems to me the only way it could possibly be a
reliable component is if the source is a laser-diode, and the strip
acts as a diffraction-grating, effectively being magnified by the
formation of interference fringes that can be readily detected when
they fall and move across the sensor. This would also mean there's a
possibility that the intervals the sensor can detect would be smaller
than those on the strip - but now I'm really just guessing

 

[Lostgallifreyan]

"PolyVinalDistillate" <PolyVinalDistillate@yahoo.co.uk> wrote in
news:1163857691.082480.116410@b28g2000cwb.googlegroups.com:

Of course I should've guessed that's where the quadrature came from!
*thinks back to his degree... QPSK and the like* Cheers for that

It could well be one of those, but the strip passing between the source
and the sensor is encoded somewhere in the order of 1/4 to 1/2 mm, so
it would need some fairly fancy optics within... The sensor is simply a
chunk of silicon around 3mm square under a protective plastic cover.
Looking at it now, it seems to me the only way it could possibly be a
reliable component is if the source is a laser-diode, and the strip
acts as a diffraction-grating, effectively being magnified by the
formation of interference fringes that can be readily detected when
they fall and move across the sensor. This would also mean there's a
possibility that the intervals the sensor can detect would be smaller
than those on the strip - but now I'm really just guessing

Without seeing it I can't say for sure, but two things to think about:
1. The sensors don't have to be at 0.25mm apart to read this
regular pattern, they could be 1.25, 2.25, so long as that fraction is
correct.
2. If you look at a cheap ball-type mouse you'll see slotted wheels that
are that finely spaced, it's not expensive tech now.

Usually the sensor surface will have two tiny slots in it. If yours really
is a single window, it might be something different. Maybe a two-element
detector that sees the shadow passing between two halves, determining
direction that way.

 

[PolyVinalDistillate]

I have used the sensors from these mice in the past, and figured out
circuitry to decode direction. However with such fine spacing on the
encoded strip with the printer sensors, and the 3mm gap between the
sensor and the source, I think there would be issues with light
diffraction were the light not coherent. By the time light from a
noncoherent source reached the sensor through the strip, it is quite
believeable that the encoding would be lost and undetectable, though I
can't be sure without a proper test of the strip back in the optics
labs to gague it's pitch properly.Under magnifying lens and with the
calipers I counted 5 lines per mm.

I also studied the sensor surface under the magnifying lens, and it
appears to be made up of many sensors on the same axis as the encoded
strip. suggesting it may well be more advanced than simply a
two-element sensor. Certainly there are not two slots on it's surface.

Cheers for the thoughts, you're pushing me closer to digging out a PSU
and firing up the ol' valve-oscilloscope to do some probing of a more
electrical nature!

 

[Lostgallifreyan]

"PolyVinalDistillate" <PolyVinalDistillate@yahoo.co.uk> wrote in
news:1163862394.947990.172310@h48g2000cwc.googlegroups.com:

I have used the sensors from these mice in the past, and figured out
circuitry to decode direction. However with such fine spacing on the
encoded strip with the printer sensors, and the 3mm gap between the
sensor and the source, I think there would be issues with light
diffraction were the light not coherent. By the time light from a
noncoherent source reached the sensor through the strip, it is quite
believeable that the encoding would be lost and undetectable, though I
can't be sure without a proper test of the strip back in the optics
labs to gague it's pitch properly.Under magnifying lens and with the
calipers I counted 5 lines per mm.

I also studied the sensor surface under the magnifying lens, and it
appears to be made up of many sensors on the same axis as the encoded
strip. suggesting it may well be more advanced than simply a
two-element sensor. Certainly there are not two slots on it's surface.

Cheers for the thoughts, you're pushing me closer to digging out a PSU
and firing up the ol' valve-oscilloscope to do some probing of a more
electrical nature!

Any motivation to use an oscilloscope is good motivation.

That sensor is interesting me a lot now, if it has several sensors built
in. It's possible they depend on equal spacing to make the same detection
as each other, in a way to reduce noise by taking a mean average or
something. Also, I don't know if the light has to be coherent, it might be
enough to be very narrow bandwidth. Some LED's are almost monochromatic, I
had a few from Hewlett Packard that were like that. Coherence can bring
troubles of its own, mainly speckle, which dramatically increases noise.

 

[PolyVinalDistillate]

I've had the sensor hooked up to 5v. Get a pretty, dull red glow from
the source, and pins 2 and 4 are indeed quadrature outputs almost
exactly 90 degrees out of phase (judging from the poor trace on my
valve oscilloscope). Direction encoded like so:

Strip Direction:1->2->3->4. 2 is 90 degrees before 4

The outputs appear to be TTL compatible (I have hooked them up to the
pushbutton circuit to a little micro for pulse counting through a
74LS148), and the device hasn't burned out on 5v I've also rigged up
the vernier caliper with the strip running through the device. Due to
my setup, I only have 1cm translation in which to measure pulses, but
after moving back and fourth 4 times through 4 cm, I've clocked up 237
pulses. This works out to around 0.17 mm per pulse, and a 50/50 duty
judging from the oscilloscope readout. The quadrature output seems to
push the accuracy to under 0.1mm... I like these parts, they have
potential

I'd overlooked speckle... though I'm not sure of it's impact were there
a narrow enough beam of light emmitted... Cretainly it appears to be
general illumination in the near-infrared that is emitting from the
source, and not a beam, which would fit in with it being relatively
monochromatic as opposed to coherent. Were it coherent, I'd have
expected the sensor to be yet more sensitive

Looks like I've got enough information to use the sensor myself now -
hope it's useful to others cannibalising HP inkjets!

And just to ensure my pinout is useful, here it is again (even though
it'll be all out of alignment when it's posted):

Top View

______
| -> | Phase1 leads Phase2 90deg
| <- | Phase2 leads Phase1 90deg
_____| |_____
|_______________|
| | | |
1 2 3 4
1: GND
2: Phase1
3: +5v
4: Phase2

 

[Lostgallifreyan]

"PolyVinalDistillate" <PolyVinalDistillate@yahoo.co.uk> wrote in
news:1163870906.385495.176430@b28g2000cwb.googlegroups.com:

I've had the sensor hooked up to 5v. Get a pretty, dull red glow from
the source, and pins 2 and 4 are indeed quadrature outputs almost
exactly 90 degrees out of phase (judging from the poor trace on my
valve oscilloscope). Direction encoded like so:

Strip Direction:1->2->3->4. 2 is 90 degrees before 4

The outputs appear to be TTL compatible (I have hooked them up to the
pushbutton circuit to a little micro for pulse counting through a
74LS148), and the device hasn't burned out on 5v I've also rigged up
the vernier caliper with the strip running through the device. Due to
my setup, I only have 1cm translation in which to measure pulses, but
after moving back and fourth 4 times through 4 cm, I've clocked up 237
pulses. This works out to around 0.17 mm per pulse, and a 50/50 duty
judging from the oscilloscope readout. The quadrature output seems to
push the accuracy to under 0.1mm... I like these parts, they have
potential

Nice, basic part, a good module to have. It rules out the more complex
business of handling analog differences, as you say it's already close to
TTL level switching.

I'd overlooked speckle... though I'm not sure of it's impact were there
a narrow enough beam of light emmitted... Cretainly it appears to be
general illumination in the near-infrared that is emitting from the
source, and not a beam, which would fit in with it being relatively
monochromatic as opposed to coherent. Were it coherent, I'd have
expected the sensor to be yet more sensitive

Coherence would have been a real problem I think, not a benefit. The
narrower the beam, the worse it gets. If you have a focussable laser
module, try focussing to a pinpoint at two feet, then drawing the spot
across a white wall, or even a fine white ceramic to show how even the
finest surfaces make huge noise. The jumps in apparent brightness will be
fierce, far worse than if you spread the light in a 3mm spot and try the
same thing.

Looks like I've got enough information to use the sensor myself now -
hope it's useful to others cannibalising HP inkjets!

And just to ensure my pinout is useful, here it is again (even though
it'll be all out of alignment when it's posted):

Top View

______
| -> | Phase1 leads Phase2 90deg
| <- | Phase2 leads Phase1 90deg
_____| |_____
|_______________|
| | | |
1 2 3 4
1: GND
2: Phase1
3: +5v
4: Phase2

I recognise it now, I've seen them in various boards I've salvaged in the
past. Some have the sensors on one side, as in this case, others have a
slot between two projections to work by transmission instead of relection,
and I think most have the same 4 wire connecting plan.

 

[PolyVinalDistillate]

I've no such laser module at my disposal to experiment with, but I
imagine you're correct. It would make sense

The only versions of these sensors I've seen before the inkjets were
the same style as those in ball-mice, with two clearly visible slits
and one light emitter. These ones are far snazzier than any of the
others in my collection! Also, these are the first I've had that are so
friendly they even save you the trouble of a couple of transistors and
schmidtt triggers to convert to TTL