audio recording on IC -help wanted

[LVMarc]

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?

Advise from a wise older EE lab rat," Things that are diffeent...are not
the same."

sounds silly ion the surface. Ususlllay this tools can explain why it
used to work and now does not.

Have fun

Marc

 

On Oct 25, 4:08 am, "Jerry Lynds" <jbly...@eastlink.ca> wrote:

I am trying to find a schematic, or even a data sheet on an IC, that will
convert analog 15.7 KHz RGBs (Composite Sync) to component video. I find a
lot of IC's that will convert to composite video or Y/C but not toYPbPr.

There are a lot of transcoder/encoder boxes to buy, but I'd like to build my
own if it is cost effective and I can have some fun building it

Jerry Lynds
jbly...@eastlink.ca

I'm looking for something similar, found Toshiba TA1287 but haven't
tried this IC yet.

 

[Joerg]

Hello John,

John Larkin wrote:

On Sat, 25 Nov 2006 16:30:01 GMT, Lostgallifreyan <no-one@nowhere.net
wrote:


"colin" <no.spam.for.me@ntlworld.com> wrote in
news:ZFZ9h.27068$hK2.1903@newsfe3-win.ntli.net:


"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:XGG9h.24992$yl4.1549@newssvr12.news.prodigy.com...

Hello Colin,

What we are measuring isn't the absolute signal which will be huge in
this case. We are after subtle differences in that signal, and a
whole lot more than 60dB. Basically we need to squeeze out all we can
get. Of course, I don't yet know what amount of noise will originate
at the DFB module. It wouldn't make sense to build a super-quiet
front end and then the laser swamps it with its own noise.

how much more do you need, another 10-20db ?
or a lot more still ? that might be difficult ..

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?

I expect you could do some noise reduction on the difference signal to
get the extra margin as 100mhz bandwidth means considerable noise,
thats if you could demodulate it somehow otherwise youl just have to
process the heck out of it with a DSP I gues.

Colin =^.^=




Or you could just cool the photodiode with a TEC. Joerg said that the laser
might make more noise than the detector though, so that might not help.


Photodiodes aren't very noisy; usually the amp's noise wins big-time.
In Joerg's case, laser noise might be the real winner.

Looks like it. When they state 10MHz line width that doesn't sound
encouraging. Who knows what's hiding behind that number. Guess we'll
find out soon. If only they had some graphs in them datasheets.

The light coming into the pd is photonized, so has shot noise, but
improving the detector can't help that.

I always wondered why nobody seems to offer the common base stages I do
in discretes as a chip but that dominant shot noise may just be the
reason. Maybe nobody really needs the stellar noise figures of a lone RF
transistor. Although, considering that most fast TIA chips are above $2
I still think there'd be a market (my amps were always much less).

BTW, an engineer from Europe mentioned a small chip company that I
almost forgot about:

http://www.ichaus.de/productgroup.php?grp=Laser_Drivers

They have a US office. But AFAICT no offerings for the receive side.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Joerg]

Hello Colin,

What we are measuring isn't the absolute signal which will be huge in
this case. We are after subtle differences in that signal, and a whole
lot more than 60dB. Basically we need to squeeze out all we can get. Of
course, I don't yet know what amount of noise will originate at the DFB
module. It wouldn't make sense to build a super-quiet front end and then
the laser swamps it with its own noise.


how much more do you need, another 10-20db ?
or a lot more still ? that might be difficult ..

In the amp I see no problem. Never done it with a TIA chip but I
designed many discrete current amps and you can hear the grass grow with
those. But if the laser source is noisy, well, then it is all water
under the bridge unless I can sufficiently "de-noise" that source.

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.

I expect you could do some noise reduction on the difference signal to get
the extra margin as 100mhz bandwidth means considerable noise, thats if you
could demodulate it somehow otherwise youl just have to process the heck out
of it with a DSP I gues.

There will be plenty of math horsepower in that machine.

--
Regards, Joerg

http://www.analogconsultants.com

 

[John Larkin]

On Sat, 25 Nov 2006 16:30:01 GMT, Lostgallifreyan <no-one@nowhere.net>
wrote:

"colin" <no.spam.for.me@ntlworld.com> wrote in
news:ZFZ9h.27068$hK2.1903@newsfe3-win.ntli.net:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:XGG9h.24992$yl4.1549@newssvr12.news.prodigy.com...
Hello Colin,

What we are measuring isn't the absolute signal which will be huge in
this case. We are after subtle differences in that signal, and a
whole lot more than 60dB. Basically we need to squeeze out all we can
get. Of course, I don't yet know what amount of noise will originate
at the DFB module. It wouldn't make sense to build a super-quiet
front end and then the laser swamps it with its own noise.

how much more do you need, another 10-20db ?
or a lot more still ? that might be difficult ..

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?

I expect you could do some noise reduction on the difference signal to
get the extra margin as 100mhz bandwidth means considerable noise,
thats if you could demodulate it somehow otherwise youl just have to
process the heck out of it with a DSP I gues.

Colin =^.^=




Or you could just cool the photodiode with a TEC. Joerg said that the laser
might make more noise than the detector though, so that might not help.

Photodiodes aren't very noisy; usually the amp's noise wins big-time.
In Joerg's case, laser noise might be the real winner.

The light coming into the pd is photonized, so has shot noise, but
improving the detector can't help that.

John

 

[Lostgallifreyan]

"colin" <no.spam.for.me@ntlworld.com> wrote in
news:ZFZ9h.27068$hK2.1903@newsfe3-win.ntli.net:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:XGG9h.24992$yl4.1549@newssvr12.news.prodigy.com...
Hello Colin,

What we are measuring isn't the absolute signal which will be huge in
this case. We are after subtle differences in that signal, and a
whole lot more than 60dB. Basically we need to squeeze out all we can
get. Of course, I don't yet know what amount of noise will originate
at the DFB module. It wouldn't make sense to build a super-quiet
front end and then the laser swamps it with its own noise.

how much more do you need, another 10-20db ?
or a lot more still ? that might be difficult ..

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?

I expect you could do some noise reduction on the difference signal to
get the extra margin as 100mhz bandwidth means considerable noise,
thats if you could demodulate it somehow otherwise youl just have to
process the heck out of it with a DSP I gues.

Colin =^.^=

Or you could just cool the photodiode with a TEC. Joerg said that the laser
might make more noise than the detector though, so that might not help.

 

[colin]

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:XGG9h.24992$yl4.1549@newssvr12.news.prodigy.com...

Hello Colin,

What we are measuring isn't the absolute signal which will be huge in
this case. We are after subtle differences in that signal, and a whole
lot more than 60dB. Basically we need to squeeze out all we can get. Of
course, I don't yet know what amount of noise will originate at the DFB
module. It wouldn't make sense to build a super-quiet front end and then
the laser swamps it with its own noise.

how much more do you need, another 10-20db ?
or a lot more still ? that might be difficult ..

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?

I expect you could do some noise reduction on the difference signal to get
the extra margin as 100mhz bandwidth means considerable noise, thats if you
could demodulate it somehow otherwise youl just have to process the heck out
of it with a DSP I gues.

Colin =^.^=

 

[Reinhard Zwirner]

John Larkin schrieb:

On Thu, 23 Nov 2006 17:08:10 GMT, Joerg
notthisjoergsch@removethispacbell.net> wrote:

I am also looking at a discrete amp for the higher frequency portion.

In a 100 MHz system, there is no "higher frequency portion"!

Everything < 1 GHz = DC? Grmmpf!

Embarrassed ;-)

Reinhard

 

[Michael A. Terrell]

Joerg wrote:

Lostgallifreyan wrote:

jasen <jasen@free.net.nz> wrote in news:epgkql$e1f$1@jasen.is-a-geek.org:


USA has been using "metric" inches for some decades now (UK also) The
ratio is exactly 1" = 25.4mm, so the worst case is three extra places
in decimal expressions,



Of course. I know this. That's the whole point. It's business as usual,
isn't it? I'm just saying ignore the bureacrats, and if they really won't
shut up, give it to them with TWELVE decimals, expressing trailing zeros,
just to annoy them. ...

... They'll soon give up and find better work to do.

Like what?

Working for the UN? ;-)


--
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

 

[Joerg]

Lostgallifreyan wrote:

Joerg <notthisjoergsch@removethispacbell.net> wrote in
news:Ho5vh.2636$MN.1839@newssvr23.news.prodigy.net:


... They'll soon give up and find better work to do.


Like what?



I can dream, can't I? >

Well, yeah, but with bureaucrats those dreams often end up in tatters
and they really come up with something they think is "better". Often
something incredibly stupid that distroys business. Like WEEE...

IMHO the society that can live with the least amount of bureaucrats per
capita is better off than others.

--
Regards, Joerg

http://www.analogconsultants.com

 

[Lostgallifreyan]

Joerg <notthisjoergsch@removethispacbell.net> wrote in
news:Ho5vh.2636$MN.1839@newssvr23.news.prodigy.net:

... They'll soon give up and find better work to do.


Like what?

I can dream, can't I? >

 

[Joerg]

Lostgallifreyan wrote:

jasen <jasen@free.net.nz> wrote in news:epgkql$e1f$1@jasen.is-a-geek.org:


USA has been using "metric" inches for some decades now (UK also) The
ratio is exactly 1" = 25.4mm, so the worst case is three extra places
in decimal expressions,



Of course. I know this. That's the whole point. It's business as usual,
isn't it? I'm just saying ignore the bureacrats, and if they really won't
shut up, give it to them with TWELVE decimals, expressing trailing zeros,
just to annoy them. ...

... They'll soon give up and find better work to do.

Like what?

--
SCNR, Joerg

http://www.analogconsultants.com

 

[Lostgallifreyan]

jasen <jasen@free.net.nz> wrote in news:epgkql$e1f$1@jasen.is-a-geek.org:

USA has been using "metric" inches for some decades now (UK also) The
ratio is exactly 1" = 25.4mm, so the worst case is three extra places
in decimal expressions,

Of course. I know this. That's the whole point. It's business as usual,
isn't it? I'm just saying ignore the bureacrats, and if they really won't
shut up, give it to them with TWELVE decimals, expressing trailing zeros,
just to annoy them. They'll soon give up and find better work to do.

 

[jasen]

On 2007-01-24, Lostgallifreyan <no-one@nowhere.net> wrote:

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
news:sn8dr29schh9jg2g31pr45tadg1qd89iko@4ax.com:

What can this possibly mean?

"EU Council Directive 80/181/EEC Requires Products to use Metric
Beginning January 1, 2010, the European Union (EU) Council Directive
80/181/EEC (Metric Directive) will allow the use of only metric units,
and prohibit the use of any other measurements for most products sold
in the EU. This will make the sole use of metric units obligatory in
all aspects of life in the EU."


Does it mean we can't use ICs with pins on 0.1" centers? Does it mean
we can't make a pc board that's 5 inches square? Is it illegal to
specify the weight of a device on a datasheet in pounds? Must the
British stop using BTUs for refrigeration and miles for distances?

Just another bout of cucumber-straightening frenzy. Work to rule. Specify
your quarter inches in explicit 12 decimal place exactitude. That should
really get up their noses.

USA has been using "metric" inches for some decades now (UK also) The
ratio is exactly 1" = 25.4mm, so the worst case is three extra places
in decimal expressions,

Bye.
Jasen

 

[Hal Murray]

Humidity is the least of your worries. In 50 years every electrolytic
capacitor in those machines will
have turned to mush - the machines will not be usuable.

What's the shelf life of modern electrolytics? (Assume room
temperature)

What about high temperature or long life models?

What's the shelf life of tantalums?

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

 

[William R. Walsh]

Hi!

and below freezing point of water, will probably display nothing.

I actually tried this once with a Samsung laptop that had a serious problem
with its mainboard. I popped it into a chest freezer for a few hours and
then powered it up when it had cooled down.

The backlight failed to come on correctly, but the dim image in the LCD
seemed fine apart from a tendency to respond very slowly.

William

 

[Mr. C]

Be very careful when applying voltages to the skin on a long-term
basis. I know from my work in the pain control business that there
should NEVER be any DC component of voltage applied to the skin. If
there is a DC component, it will cause skin irritation. If you did
want to run wires of any kind, just be sure they are insulated from
the surface of the skin.

 

[Hal Murray]

No. Sustained exposure to 10 degrees F will freeze and permanently
damage the display, unless the laptop is explicitly designed and built
to withstand such (only your spec sheet will tell you).

Why don't we hear more war stories from people who left their
laptop in the car overnight in the northeast winter?

--
These are my opinions, not necessarily my employer's. I hate spam.

 

[Lostgallifreyan]

Chris Jones <lugnut808@nospam.yahoo.com> wrote in
news:12tn46bsii4u649@corp.supernews.com:

Since cables from your multi-wart are going to drop a significant
amount of voltage anyway, I think it is not useful to attempt very
close regulation of the output voltage. In that case, it might be
quite feasible and cheap for each output of the multi-wart to be
floating with respect to all of the others, since all of outputs could
be derived from separate secondary windings on the SMPS transformer.
If it is a small flyback converter, each winding would need a diode
and a couple of capacitors, and the regulation could be based on just
one of the outputs. Each output would not have very good regulation
(but cable will ruin the regulation anyway), and the outputs would all
be isolated, permitting people to ground whatever parts they want
without the power supply causing any particular extra problem.

Nice idea. I've considered the floating output too, it allows a star
network ground without current induced voltage drops, and a cure for
polarity differences, though only up to a point. It's still possible to
common the wrong terminals through a chain of equipment, possibly with
disastrous compound failures resulting. In short, separate isolated outs
won't solve the problem of incompatibly chosen polarites, only agreement
and co-operation can do that. (Or, possibly, litigation by the those
adhering to the dominant standard against those of the other, in cases
where deliberately chosen incompatibility causes another firm to lose money
because of damage and lost customers).

The current in a grounded supply negative can cause bother, I agree, but
there are two ways to deal with it in current use. (I like bad puns). One
is a coax DC line. That lowers the negative rail resistance enormously,
reducing the voltage difference from negative to earth, and screens the
positive line which is also useful. The other is a psuedo-balanced audio
line. Even basic designs can use a common mode cancelling input to remove
the noise, and a twin core shielded by a screen that is connected at only
one end. The problem isn't really the use of a common standard with a
common ground, audio gear manufacturers deal with this all the time, and
they get by, and standards help there, the problem is when makers ignore
standards founded in good sense, like those you mention who ignore the
limits of a USB 5V line.

Re the lack of useful regulation due to line losses, I agree, which is why
I think local regulators will still be needed. My point is that it's no
longer expensive to have a small room or house local buss for 5V and 12V. A
lot of stuff will be fine plugged right in to one or the other with only
basic protection against use with the wrong buss.

I don't even think that any kind of standardisation needs to be drafted in
some kind of comittee. All it needs is some firm to start punting them out,
and people WILL buy them. It worked for the universal remote control. If
end users can get their heads round that, they'll not have much trouble
with a 12V/5V distributing board. It just needs someone willing to make
them, and then other firms will want to make sure their products will work
with them.

 

[Peter A Forbes]

On Tue, 20 Feb 2007 20:05:56 GMT, "Homer J Simpson" <nobody@nowhere.com> wrote:

"Bud--" <remove.BudNews@isp.com> wrote in message
news:da2ea$45db3feb$4213eb86$2385@DIALUPUSA.NET...

When MOVs fail they can overheat.

Or shoot flames out of the top!

Or explode. We had some large block MOV's across some electrolytics in a big
620V 150A power supply/charger. Occasionally we would get a start-up spike from
the thyristor bridge that popped one, huge flash and bang and lots of smoke.

Eventually found some high voltage elco's that obviated the need for the MOV's
in the first place. The original elco's were failing through spikes which is why
the MOV's were fitted!

Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
Web: http://www.oldengine.org/members/diesel