audio recording on IC -help wanted

[Andre Majorel]

On 2008-07-12, Baron <baron.nospam@linuxmaniac.nospam.net> wrote:

Andre Majorel wrote:

Manufacturers tend not to give a figure for the number of
insertions their DIN connectors can take. I've never seen one
fail but those don't tend to be the type you plug/unplug ten
times a day. Does anyone have data or experience with that ?

Yes I do this far more often ! I've yet to have a plug fail,
but I have had the odd socket loose a leg from the mating
part. After that all you can do is replace the socket. Which
sadly I've had to do several times.

I see, thanks. I'm after an 8- or 9-way connector for a home
brewed polyphonic modular synth. Frequencies involved are DC to
20 kHz, 30 Vpp, input impedances on the order of 100 k.

Modular connectors (RJ45-style) have for them low cost and the
availability of pre-made patch cords. But when life expectancy
is specified, it is very low, on the order of dozens of cycles.

High quality DE-9 are available but even the Canon ones are only
spec'd to a few hundred insertions at most. And there is the
problem of making a D-shaped hole in the panel.

It better be a low-cost part because I'll need several hundreds.
In itself, replacing a panel connector is not a big deal if
there is a wire-to-board connector behind it. The problem is
that spotting one bad contact can take a while.

--
André Majorel <URL:http://www.teaser.fr/~amajorel/>
"Buy in bulk, that's my advice." -- Lemmy

 

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[Roderick Stewart]

In article <46ff32e0$0$32538$4c368faf@roadrunner.com>, Green Xenon [Radium]
wrote:

And, as we've been trying to make clear, your goal is quite far beyond
 > the theoretical limit.  You just can't get there.  You're trying to
 > put all of Lake Erie in a water-glass.
 
 > Let it go, Radium.

Within physical-possibility, what is the largest amount of 
bits-per-symbol [assuming a baud-rate of only 1-bit-per-symbol] that can 
be reached without the highest-voltage causing any clipping, generating 
any temperatures above 70 Fahrenheit, resulting in any harm to 
anyone/anything [including the equipment itself], or shortening the life 
of the equipment and without the lowest-voltage being lost in the noise? 
What is the maximum-possible amount of discrete levels between the 
highest and lowest voltage in such a signal?

An 8-bit signal can have a maximum of 256 different voltage levels 
between the highest and lowest voltage. Right? Go too high and the 
signal clips, go too low and the signal will not be recognized.

I tell you what. Why don't you build one of these magic modulators, show us
that it works, and then we'll believe you.

If it does, I might be encouraged to have a go at making that machine I
invented at the age of about seven, even though my dad told me it wouldn't
work. My plan was to use an electric motor to turn a dynamo, which would
generate electricity, which would then be used to power the electric motor.
After it had been patiently explained to me that the amount of electricity
generated would not be enough to power the motor, my next idea was to
interpose some gears or pulleys so that the motor would turn the generator
a little faster, thereby generating more electricity. My understanding of
the physical world had some way to go, but we all have to start somewhere.

Rod.

 

Watch the TV ads. The best gifts always go fast. Excellent
deconstruction of a television ad. This format would be an especially
effective way to educate children about the ads they see on kid-
oriented TV, ...


http://tv-tv-television.blogspot.com

 

[Eeyore]

Lostgallifreyan wrote:

Eeyore wrote

LEDS operate at lowish voltages. You tend to get lower efficiencies
with at lowish voltages, largely due to rectifier losses.

I doubt you'll much better 85% power conversion efficiency overall
from the AC line to the LED package actually. That would be a *very*
good figure.

LED drivers chain LED's to limit that problem. The one I bought can chain 7
LED's.

Even then, the seondary rectifiers alone will consume about 5% of the power.

Graham

 

[me]

Looking for a vintage(around 1988) remote control,the model on the AKAI AV
receiver is AA-V205.
The model on the remote control is RC-A905. I thought someone might have a
working one laying around
collecting dust that they would part with. Thanks

 

[Eeyore]

ChairmanOfTheBored wrote:

Couldn't he just make a Darlington pair from two of the cheap 2n2222s?

And what's the Vce(sat) of a darlington ?

Graham

 

[Ross Herbert]

On Sat, 03 Jan 2009 22:51:18 -0900, floyd@apaflo.com (Floyd L. Davidson) wrote:

:"Phil Allison" <philallison@tpg.com.au> wrote:
:>"Ross Herbert"
:>
:>>
:>> Since the application is merely detecting signal "voltage" it hardly
:>> matters
:>> that the secondary impedance of the transformer is 600 ohms and the input
:>> impedance of the sound card is more like 10Kohms.
:>
:>** Fact is, it will be an advantage as the load across the phone line
:>needs to be high as possible so the level there is not affected.
:
:No, it merely needs to be "high enough", not "high as
ossible". If the bridging device has ten times the
:circuit impedance, there will be a 0.3 dB drop in levels
n the circuit, and a 30 dB loss across the bridging
:device.
:
:That is considered satisfactory for virually all
:applications. In this instance it would probably be
:satisfactory if the bridging impedance where half that.
:
:Regardless, you 10k Ohm value is absurd.
:
:>> The only reason one tries to
:>> match impedances is where one needs to maximise "power transfer" and that
:>> doesn't apply in this case.
:>
:>** Nonsense.
:>
:>Audio and other wide band transformers have rated ( ie optimum) source and
:>load impedances.
:>
:>This relates *directly* to them both operating efficiently AND exhibiting
:>their specified frequency response curve.
:>
:>Eg, a 600:600 ohm type operating into 10 kohms may well have a large
:>response peak at high frequencies while a 10k:10k type operating into 600
:>ohms will likely have serious roll off from a few kHz upwards.
:
:So read what you just wrote, and tell us how that affects a telecom
:circuit that is specified at 400-2800 kHz?

Should that not be Hz?

If so, voice frequency circuits were all 300 - 3400Hz in my day.

Phil is just being a bit too specific. My remarks were applicable specifically
to the VF telephony freq range, which is the area of interest to the OP.

:
:>With transformers that have 1:10 or 1:20 step-up ratios for mic-input to a
:>valve stage, both load and source impedances become quite critical just to
:>stay within a +/- 2dB corridor across the audio band.
:
:At perhaps 15-20 kHz. So just who cares, in this case?

Exactly!

 

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[ChairmanOfTheBored]

On Tue, 01 Jan 2008 18:00:04 -0500, Fred Bloggs <nospam@nospam.com>
wrote:

Lee K. Gleason wrote:
"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:tJyej.174$T05.48@newsfe06.lga...

gleason@encompasserve.org wrote:


I need to switch some GE #44 lamps from a TTL output. #44 lamps are

6.3 volts

at 250 ma, so I'll need a transistor to do the real work. Unfortunately,

it's

just a hair too much power for one of the hundreds of surplus 2n2222's

I keep

around to do almost everything else here. Can someone suggest a small,

cheap

available transistor that would be appropriate for this use?
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net

where did you get the idea the 2222's can't handle that?
You need to saturate them,. They can handle 500 ma's so
said this PDF..

http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

The trick is to saturate the bias so that very little
resistance effect is between the CE.


I was concerned about the total power rating of 500 milliwatts for the
2n2222. Power here would be around a watt and a half...
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net



Look here at figure 2:
http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

The little detail is that "beta=10" thingamjig...that means if you drive
the base with 25mA, the Vce at 250mA will be less than 0.2V. This makes
the Pd = 0.25A x 0.2V= 0.125W. Now look at figure 3, Vbe,sat, at 250mA
is about 0.9V. Use this to compute the voltage bucking your TTL drive.
Then the base dissipation is 0.025A x 0.9V=0.0225W. The grand total is
0.0225+0.125=0.1475W. Now go up to the top and look at R theta,j-a, of
200oC/W for the TO-92 plastic, that gets you 200oC/W x 0.1475W=29.5oC
junction rise above ambient. Now look at Tstg under max ratings, it says
150oC, this means you will be fine at ambients less than 150-30=120oC.
recall this is 120x1.8+32=250oF. Which TTL part are you using to drive
it? The 25mA base drive would suggest something called a *buffer*.

What about the 2222s in the can?

 

[John Fields]

On Thu, 19 Jul 2007 15:09:32 GMT, "Dave"
<dspear99ca@yahoo.delete.com> wrote:

I've got an electronic device which operates, at least it used to operate,
using a car battery as a power source. Over time it has begun to complain
about low battery voltage which causes the unit to shut down. The battery
voltage is fine... when I hook it up to the battery in my car and leave the
car running (~14.4VDC while charging) the device will run indefinitely.
So... it would appear that whatever is sensing the input voltage is sensing
the voltage incorrectly.

---
Another possibility is that your battery is coming to the end of its
useful life and its capacity has been diminished.

To find out, connect a voltmeter across the load without the engine
running and track it until your device shuts down. Track it,
because as soon as the load shuts down the battery voltage will rise
and you want to know where it was when shutdown occurred.
---

So... my options are to open up this device (it's a sealed, ruggedized,
evacuated of air, computerized survey total station so this would be my 2nd
choice) to have a look at the (no doubt) SMT microcircuitry within, or to
find a device which will give me a regulated, say, 13.8VDC from my 12V wet
cell.

Can anyone point me at a retailer who sells 12V-12V converters with
regulated boosted voltage? I've only found one at
http://www.electroparts.com.au/volatge_boosters.htm but a) they are in
Australia and I am in Canada and b) these units are 8A and up whereas I only
require maybe 1A max. Otherwise the description of this device is EXACTLY
what I want.

Somebody must make these things, maybe for RV's or sailboats or so
solar-powered survivalists can write their manifestos on laptop computers...

Any help greatly appreciated.

---
If you're willing to build something, take a look at:

http://www.national.com/appinfo/power/switcher.html


--
JF

 

[Jim Thompson]

On Tue, 01 Jan 2008 18:00:04 -0500, Fred Bloggs <nospam@nospam.com>
wrote:

Lee K. Gleason wrote:
"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in message
news:tJyej.174$T05.48@newsfe06.lga...

gleason@encompasserve.org wrote:


I need to switch some GE #44 lamps from a TTL output. #44 lamps are

6.3 volts

at 250 ma, so I'll need a transistor to do the real work. Unfortunately,

it's

just a hair too much power for one of the hundreds of surplus 2n2222's

I keep

around to do almost everything else here. Can someone suggest a small,

cheap

available transistor that would be appropriate for this use?
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net

where did you get the idea the 2222's can't handle that?
You need to saturate them,. They can handle 500 ma's so
said this PDF..

http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

The trick is to saturate the bias so that very little
resistance effect is between the CE.


I was concerned about the total power rating of 500 milliwatts for the
2n2222. Power here would be around a watt and a half...
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net



Look here at figure 2:
http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

The little detail is that "beta=10" thingamjig...that means if you drive
the base with 25mA, the Vce at 250mA will be less than 0.2V. This makes
the Pd = 0.25A x 0.2V= 0.125W. Now look at figure 3, Vbe,sat, at 250mA
is about 0.9V. Use this to compute the voltage bucking your TTL drive.
Then the base dissipation is 0.025A x 0.9V=0.0225W. The grand total is
0.0225+0.125=0.1475W. Now go up to the top and look at R theta,j-a, of
200oC/W for the TO-92 plastic, that gets you 200oC/W x 0.1475W=29.5oC
junction rise above ambient. Now look at Tstg under max ratings, it says
150oC, this means you will be fine at ambients less than 150-30=120oC.
recall this is 120x1.8+32=250oF. Which TTL part are you using to drive
it? The 25mA base drive would suggest something called a *buffer*.

The initial current surge (maybe 10x of normal) of the light bulb will
likely take out the transistor unless some sort of "soft-start" is
implemented.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

 

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[GPE]

"Lee K. Gleason" <lee.gleason@comcast.net> wrote in message
news:VLadnfYYge32XefanZ2dnUVZ_rKtnZ2d@comcast.com...

"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
message
news:tJyej.174$T05.48@newsfe06.lga...
gleason@encompasserve.org wrote:

I need to switch some GE #44 lamps from a TTL output. #44 lamps are
6.3 volts
at 250 ma, so I'll need a transistor to do the real work.
Unfortunately,
it's
just a hair too much power for one of the hundreds of surplus 2n2222's
I keep
around to do almost everything else here. Can someone suggest a small,
cheap
available transistor that would be appropriate for this use?
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net
where did you get the idea the 2222's can't handle that?
You need to saturate them,. They can handle 500 ma's so
said this PDF..

http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

The trick is to saturate the bias so that very little
resistance effect is between the CE.

I was concerned about the total power rating of 500 milliwatts for the
2n2222. Power here would be around a watt and a half...
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason@comcast.net

That would need to be a pretty high saturation voltage in the transistor to
get 1.5W at 250mA.

The MPSA13 is rated at 625mW. With a saturation voltage of 1.5V and 400mA
(typical GE44 is actually about 400mA) -- you're dissipating 0.6W... maxing
out the MPSA13. Pinball people have been using MPSA13's and GE44 bulbs for
years. The biggest problem happens when the bulb burns out. Unpredictable
things happen within the bulb when they burn out -- sometimes the filliment
will break, move and 'reweld' itself to a different place in the
filliment -- giving a brighter bulb...and short lifespan on the transistor.

You can also go with a type 47 bulb. Same voltage but about 250mA. Less
current so less power dissipated by transistor. Down side is the bulb is
considerably dimmer.

-- Ed

 

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[Ross Herbert]

On Tue, 26 Jun 2007 15:13:48 GMT, "ian field" <dai.ode@ntlworld.com>
wrote:

"mc" <look@www.ai.uga.edu.for.address> wrote in message
newsv9gi.6990$c_4.1098@bignews2.bellsouth.net...

"ian field" <dai.ode@ntlworld.com> wrote in message
news:R19gi.5262$nE2.1789@newsfe3-win.ntli.net...
Does anyone know if Evolube (possibly Elvolube) still exists?

Apparently so:

http://www.ecllube.com/003products.aspx

Haven't found anyone selling it in small quantities, but the
manufacturer
can presumably direct you to a distributor.

Yes - my google search found several references to that family of
automotive
lubricants, apparently an assortment of grades in a variety of
colours.

Mostly extreme water resistance and greases that increase in
viscosity in
response to shear (probably not very good for "wiping" contacts!).

Looking at the ECL products info it would appear that Evolube is not
the best choice for switch contacts. Rheogel 283 and Absolube 411A are
suitable for this use however.

 

[Joerg]

Jamie wrote:

Joerg wrote:

Hello,

Just curious, although I am not holding my breath that any exist:

Are there FETs with a Vds rating of 300V or higher, preferably DPAK
(TO-252), that have a guaranteed Rdson of around 1ohm or less at Vgs
of 6V or less? 1A current or higher.

With guaranteed I mean not in some graph but with an entry under "max"
in the tables. The usual ones are only rated at 10V although the
figures indicate that they could have rated them for lower gate drive
voltages at lesser current. But the manufacturers chose not to and
trying to get any endorsement to that effect is like kicking a big oak
tree.

The motivation is the usual. Logic drive, the typical MIC4422 or
similar is too much money plus it would need its personal supply
voltage which would have to be made.

http://www.datasheetcatalog.com/datasheets_pdf/S/T/B/2/STB20NK50ZT4.shtml

how about that ?

Like usual, Rdson max only guaranteed at 10V and the transfer
characteristic looks rather spooky. It's most likely going to explode if
you try to switch heavy loads at 5V:

http://www.st.com/stonline/products/literature/ds/9118/stb20nk50z.pdf

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Dear Leader]

"Tom Potter" <tdp1001@yahoo.com> wrote in message
news:46cc5dd6$0$8173$88260bb3@free.teranews.com...

"Dear Leader" <spamless@spamless.com> wrote in message
news:46cc3b78$0$97274$892e7fe2@authen.yellow.readfreenews.net...

"Tom Potter" <tdp1001@yahoo.com> wrote in message
news:46cc26cc$0$16357$88260bb3@free.teranews.com...

A high resolution, handheld, RADAR system can be made

already done. google for it.
you should get out more, read books and mags.

I assume that "Dear Leader" is talking about
hand-held, police RADAR
used to determine the speed of cars.

If not, hopefully he will provide references to where
a hand-held RADAR is used to plot one's position
and the positions of moving targets
on a Goggle-like map.

There is a world of difference between what I propose,
and a hand held Doppler RADAR.

what do you think a police radar is, dummy?

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

 

[Lostgallifreyan]

don@manx.misty.com (Don Klipstein) wrote in
news:slrnf9qfci.t4p.don@manx.misty.com:

In article <Xns996CE369B8CD8zoodlewurdle@140.99.99.130>,
Lostgallifreyan wrote in part:
"Albert Manfredi" <albert.e.manfredi@nospam.com> wrote in
news:JL4t9u.6IK@news.boeing.com:

Others and I have speculated the "why" people might prefer "warmer"
lighting. There's nothing wrong with speculation. That's what leads
to stating a hypothesis and then trying to prove it, and possibly
ending up with a physical law.

It's a physical law that shorter wavelengths render finer detail.

Can you cite how in human vision, where diffraction limitations are
not
an issue?

Perhaps they are? I don't see how they can be, being a thousandfold smaller
than what we're likely to be seeing, but if I try seeing detail with red
light there's a definite lack of the sharpness of detail that I see if I
use blue light. Whatever the cause of the effect, it's definitely there,
and I have no known abberations of vision so I must assume I am not alone
in this.

 

[Lostgallifreyan]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:469331FE.2846E5C4@hotmail.com:

I've yet to see a spectrum published for those 'white' leds. I assume
it must be similar to CFLs.

?
That Cree document I cited has extensive detail. Several graphs for various
types. Also, they do a 'binning and labelling' document that shows plots of
all types on a cromaticity diagram. I had to think a bit to work out where
my LED torch was on that, but it's all there.