audio recording on IC -help wanted

[Watson A.Name - \"Watt Su]

"legg" <legg@nospam.magma.ca> wrote in message
news:93hj81p6d97en58h8lai1l5kmj7rt0dkrf@4ax.com...

On Mon, 16 May 2005 19:30:04 -0500, "Brian" <spam@whatisitgood.for
wrote:

OMG! Buy a new pair of headphones!

Valley Girls and soldering irons, a curious mix.

RL

Valley Girls? More like IM freak. I was watching one young lady IMing
yesterday and it was pretty much shorthand for words, like u and b4 and
y not and etc. A really good way to ruin the english skills of the
younger generation.

 

[John Fields]

On Tue, 17 May 2005 05:39:44 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

"legg" <legg@nospam.magma.ca> wrote in message
news:93hj81p6d97en58h8lai1l5kmj7rt0dkrf@4ax.com...
On Mon, 16 May 2005 19:30:04 -0500, "Brian" <spam@whatisitgood.for
wrote:

OMG! Buy a new pair of headphones!

Valley Girls and soldering irons, a curious mix.

RL

Valley Girls? More like IM freak. I was watching one young lady IMing
yesterday and it was pretty much shorthand for words, like u and b4 and
y not and etc. A really good way to ruin the english skills of the
younger generation.

---
"English".


--
John Fields
Professional Circuit Designer

 

[mc]

I think by mA you mean mAH throughout.

If you put unmatched batteries in series, one will discharge first, and then
the other one will reverse-charge it by continuing to drive current through
it. With NiCd cells this causes immediate severe damage. I'm not sure
about Li-ion, but it sounds from your description as though the results were
equally fatal.

 

[mc]

BTW, if you needed 4 volts, why did you put them in series? Was 3.7 V not
enough?

In parallel, batteries of matched *voltage* are OK, regardless of whether
the capacities match. The strong ones recharge the weak ones, rather than
reverse-charging them. But if one battery shorts or becomes electrically
leaky, it will discharge all the others.

The 3.7-volt, 750 mAH (if it's mAH) battery will supply 3.7 V to your 30-mA
load for about 24 hours.

If you need technical assistance with your design, please drop me a line (mc
at uga dot edu). I'm in speech science myself.

 

[Peter A Forbes]

On Sat, 21 May 2005 08:18:06 -0700, "Watson A.Name - \"Watt Sun, the Dark
Remover\"" <NOSPAM@dslextreme.com> wrote:

So far in my several score of Ebay purchases, I have had several that
were shoddy, and i've had to send many of those back to get a refund.
I've had nowhere near as many problems with store purchases, or
purchases from online retailers.

We have been more fortunate with ebay, not yet had a bad one other than a
displaced galvanometer movement probably caused by postal handling.

It does depend a lot on what you are buying and how much you have paid IMO. The
guy who gets a reasonable price for his sale is more likely to pack properly etc
than the guy who expected $15 and got $2 for example.

I had one like that last week or so, he wanted $15 for posting some packs of
plotters pens internally in the USA, while we were able to point out to him that
$5.50 was more than sufficient.

Takes all sorts! )

Peter

 

[Watson A.Name - \"Watt Su]

"Peter A Forbes" <diesel@easynet.co.uk> wrote in message
newsrmu81tbagc1t92qaels95u799k62hvjbm@4ax.com...

On Sat, 21 May 2005 08:18:06 -0700, "Watson A.Name - \"Watt Sun, the
Dark
Remover\"" <NOSPAM@dslextreme.com> wrote:

So far in my several score of Ebay purchases, I have had several that
were shoddy, and i've had to send many of those back to get a refund.
I've had nowhere near as many problems with store purchases, or
purchases from online retailers.

We have been more fortunate with ebay, not yet had a bad one other
than a
displaced galvanometer movement probably caused by postal handling.

It does depend a lot on what you are buying and how much you have paid
IMO. The
guy who gets a reasonable price for his sale is more likely to pack
properly etc
than the guy who expected $15 and got $2 for example.

I had one like that last week or so, he wanted $15 for posting some
packs of
plotters pens internally in the USA, while we were able to point out
to him that
$5.50 was more than sufficient.

Takes all sorts! )

Peter

Speaking of which...
Well, I _finally_ got Tucker (tucker.com) to agree that they weren't
allowed to charge tax on shipping. It took several emails and phone
calls, and finally I got hold of the lady in accounting, who said she'd
call me back, and finally she did, and allowed me to not pay taxes on
shipping. I could've showed them the Calif Board of Equalization FAQ
that says that shipping (the FAQ calls it transportation) is not
taxable. And I could've showed them the federal law that says it's
illegal, for example, for a seller in Taxes to apply Texas tax
regulations to a buyer who's a resident of California.

I hope they get their act together and don't subject any more buyers to
those hassles.

 

[Spehro Pefhany]

On 24 May 2005 11:18:51 -0700, the renowned "Bo-Ming Tong"
<cyberstudio@shaw.ca> wrote:

I am developing a product which requires interfacing my 5V circuit to
another 5V circuit whose power supply I have no control over, which
varies from around 4.75V to 5.25V in practice.

I wish to build my circuit's power supply to track the other circuit's
power supply instead of a fixed 5V. So, I am looking for a regulator
with an external voltage reference instead of an internal one. I need
only 40mA, and I have found ON Semiconductor CS8182 (SOIC-8) and
Infineon TLE4250G (SCT-595) for that purpose. However, they are not
stocked by suppliers such as Mouser and Digikey, and I have learned
from posts in this newgroup that I should never design-in
hard-to-source components. Is there any other tracking LDO you could
think of, which is extremely small and made by a more commonly
available manufacturer such as TI ?

I also found a lot of DDR termination tracking controllers but they are
all 1:2 and they are larger than my very constrained space would allow.

Thanks in advance !

Maybe you could use an LM723 in SO-14 plus 2R and 1C ? ;-)



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[legg]

On 24 May 2005 11:18:51 -0700, "Bo-Ming Tong" <cyberstudio@shaw.ca>
wrote:

I am developing a product which requires interfacing my 5V circuit to
another 5V circuit whose power supply I have no control over, which
varies from around 4.75V to 5.25V in practice.

I wish to build my circuit's power supply to track the other circuit's
power supply instead of a fixed 5V. So, I am looking for a regulator
with an external voltage reference instead of an internal one. I need
only 40mA, and I have found ON Semiconductor CS8182 (SOIC-8) and
Infineon TLE4250G (SCT-595) for that purpose. However, they are not
stocked by suppliers such as Mouser and Digikey, and I have learned
from posts in this newgroup that I should never design-in
hard-to-source components. Is there any other tracking LDO you could
think of, which is extremely small and made by a more commonly
available manufacturer such as TI ?

I also found a lot of DDR termination tracking controllers but they are
all 1:2 and they are larger than my very constrained space would allow.

A surplus error amplifier could be used to modify your presently-used
circuit, by driving the summing point through an impedance much larger
than that of the voltage divider that is already in place. This would
only 'trim' the voltage.

Perhaps this might not use much more real estate.

RL

 

[guy pastuzak]

"signo" <msignorini@calearotlc.com> a écrit dans le message news:
1117021944.214012.320180@g43g2000cwa.googlegroups.com...

Is my boss right? Am I right? Are we both wrong?

Hello Massimo

Sorry ;o((

I think your boss is right
--
Guy Pastuzak

Adresse ANTISPAM
ANTISPAM address

 

[Walter Harley]

"Bo-Ming Tong" <cyberstudio@shaw.ca> wrote in message
news:1116958731.033512.251910@f14g2000cwb.googlegroups.com...

I am developing a product which requires interfacing my 5V circuit to
another 5V circuit whose power supply I have no control over, which
varies from around 4.75V to 5.25V in practice.

I wish to build my circuit's power supply to track the other circuit's
power supply instead of a fixed 5V. So, I am looking for a regulator
with an external voltage reference instead of an internal one. I need
only 40mA, [...]

How about using a rail-to-rail opamp, in unity-gain buffer configuration?
I'm sure you can find plenty with that kind of current capability.

 

[Spehro Pefhany]

On 25 May 2005 10:59:18 -0700, the renowned "Bo-Ming Tong"
<cyberstudio@shaw.ca> wrote:

Thanks. That's an excellent idea !

The only potential pitfall I see is that my power could be turned off
(hence turning off the opamp) but the reference voltage (the circuit I
am interfacing to) is still on. Then I will be applying a voltage much
higher than Vdd to the opamp.

You can put series resistance in there to limit the current. One thing
you should be careful of if you try this is that most op-amps will
happily oscillate away when connected directly in a unity-gain
configuration to typical power supply bypass capacitors, so you need
to decouple the op-amp output from any serious capacitive loading (and
make sure that your compensation doesn't allow it to overshoot too
much).


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Spehro Pefhany]

On 25 May 2005 12:05:16 -0700, the renowned "Bo-Ming Tong"
<cyberstudio@shaw.ca> wrote:

Yes, thanks for the advice...

I am rethinking this a bit due to the advice of you and Walter. The
reason why I wanted my power supply to track the other power supply is
that I am afraid of the I/O pin protection clamp diode conducting (on
either side), blowing things up. But as I think about it, using a
high-current rail-to-rail opamp leads me back to exactly the same
original problem that I am trying to solve. I am just dealing with a
protection diode in a different place. And on top of that I need to
worry about output capacitance like you said.

As you can see I have about 0.3V voltage difference between the 2 power
supplies. I guess I can just add 10k resistors to each pin of the
interface. If the power supply differences turns out to be great enough
to trip the protection diodes (in the normal case this should not
happen), the protection resistors should be able to limit the current
and saving me from blowing things up.

Let me preface this by saying that I don't have a clear idea of what
you are trying to do. Is this correct?

i) You have system A with a power supply that's "about" 5V.

ii) You are designing system B that has logic level connections to
system A.

iii) You wish it to be reliable.

If that's correct, maybe you can just use level translation methods to
deal with any mismatch.

Simplest way is to put some series resistance in the signal lines. I
won't go into that, there are plusses (cost, mostly) and minuses (may
violate the abs max input voltage rating, may cause unforseen effects,
slows down signals etc.).

You could also use 74HC4049/50s (with dual Vcc connections- one Vcc
for inputs- tied to the internal Vcc, and one Vcc for outputs- tied to
the external Vcc) or other level translation chips to inexpensively do
this. That part will tolerate inputs as high as 16V and has a
reasonable input threshold for CMOS. There are also other specialized
level-translation devices:

http://focus.ti.com/pdfs/logic/dsprodclip.pdf

The 74LVC245 is one jellybean choice (accepts inputs as high as 5.5V)



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

"Bo-Ming Tong" <cyberstudio@shaw.ca> wrote:

Is there going to be any problem if I interface two CMOS logic systems
together with a constant Vcc difference of 0.3V ?

IIRC, even CMOS doesn't swing rail-to-rail, so you shouldn't have any
trouble. The only time you would have a problem would be when one
power supply goes away, but why not run your circuit off the Vcc from
the other circuit, CMOS is pretty low power...

 

[Jim Adney]

On 24 May 2005 11:18:51 -0700 "Bo-Ming Tong" <cyberstudio@shaw.ca>
wrote:

I wish to build my circuit's power supply to track the other circuit's
power supply instead of a fixed 5V.

How about an op-amp with a transistor added, emitter follower style?

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

 

[Al]

In article <1117134068.147859.231470@o13g2000cwo.googlegroups.com>,
"amit" <amit.kohan@gmail.com> wrote:

Hello,

As far as I know you can use PIC with its Basic language compiler. What
about C/C++? does it support the C programming language too?

Any suggestions for somebody new to this field? so far, I have read
some books about Digital design and programming. what else do I need?

thanks,
amit

Check out http://www.ccsinfo.com/picc.shtml

Their C compiler works fine for me.

Al

 

[petrus bitbyter]

"Al" <no.spam@wanted.com> schreef in bericht
news:no.spam-FD77C2.15160526052005@news.verizon.net...

In article <1117134068.147859.231470@o13g2000cwo.googlegroups.com>,
"amit" <amit.kohan@gmail.com> wrote:

Hello,

As far as I know you can use PIC with its Basic language compiler. What
about C/C++? does it support the C programming language too?

Any suggestions for somebody new to this field? so far, I have read
some books about Digital design and programming. what else do I need?

thanks,
amit


Check out http://www.ccsinfo.com/picc.shtml

Their C compiler works fine for me.

Al

The only good C compiler for PICs I know is from Hi-Tech. But it's an
expensive one. Never used CCS so can't say a thing about it.

petrus bitbyter

 

[news.btinternet.com]

Hi-Tech do a free version of their C compiler called PICC Lite -
http://www.htsoft.com/products/PICClite.php - integrates nicely with the
Microchip IDE

 

[EN]

"isaac" <ssamlove79@naver.com> wrote in message
news:1117159919.949571.325770@o13g2000cwo.googlegroups.com...

LS7232ND
I need a datasheet for LS7232ND LAMP DIMMER(LSI)

Does anybody know where I can find one or something that can help me
out? I Can not found in any places on the Internet

try here,

http://www.digchip.com/datasheets/parts/datasheet/502/LS7232-DIP.php

 

[Don Baker]

If you elect to stay with fans, I had good luck with fans from
acoustiProducts. (vendor http://www.siliconacoustics.com). I used these
for an OR application, trying to surgeons happy. They really were quieter
that :Standard" fans.

Hear a few of the other manufacturers of reduced noise fans. IMHO, you
really need to look carefully as the word quiet is very subjective.

Specifications for Panaflo and for Cormair Rotron Whispers are from
www.comairrotron.com

Specifications for NMB fans are from www.nmbtech.com

Specifications for JMC fans are from www.jmcproducts.com (good ANSI specs)

Noiseblocker fan specs from www.Blacknoise.de, but good luck finding the
fans in North America.

Verax fan specs from shop.erfrier.net (German). I'm not sure if they are
available in North America

Don


<shoppa@trailing-edge.com> wrote in message
news:1117280737.210395.281170@g47g2000cwa.googlegroups.com...

I'm the new proud owner of a R-390A. (Some will say I'm a fool but
I had to follow my heart!) It's rackmount, which is great because
I've got rack space. I want to keep it well fed and ventilated.

At the moment, the rack has a 10" EG&G/Caravel Rotron fan in the top.
It moves a lot of air and generates a fair amount of noise. Not
bad in a computer room, but I want to hear the radio instead of the
fan.

I anticipate keeping the R-390A on more regularly than my other tube
radios (Heathkits etc.). Probably several hours a day.

In addition, the radio probably isn't as thermally stable as it could
be if
I'm sucking lotsa air through it. Someone might tell me that it's
bad to use a fan for some other reason.

Which way to go? Speed control on the fan to slow it down and keep
it quiet? No fan at all, because the R-390A was designed not to need
it? Some vastly more quiet and appropriate fan?

Tim. (KA0BTD)

 

[John DeGood]

My experience is that ordinary fans run at reduced voltage are a great
way to achieve quiet operation. The muffin fans in HP 264x CRT
terminals ran virtually silent because HP operated them at 1/2 their
nameplate voltage. I cool my old Heathkit boatanchor rig with a 12 V
brushless DC muffin fan that is silent because I run it at 6 V. If your
rack has 2 fans an easy solution is to simply wire them in series so
they run at 1/2 voltage.

John

shoppa@trailing-edge.com wrote:

I'm the new proud owner of a R-390A. (Some will say I'm a fool but
I had to follow my heart!) It's rackmount, which is great because
I've got rack space. I want to keep it well fed and ventilated.

At the moment, the rack has a 10" EG&G/Caravel Rotron fan in the top.
It moves a lot of air and generates a fair amount of noise. Not
bad in a computer room, but I want to hear the radio instead of the
fan.

I anticipate keeping the R-390A on more regularly than my other tube
radios (Heathkits etc.). Probably several hours a day.

In addition, the radio probably isn't as thermally stable as it could
be if
I'm sucking lotsa air through it. Someone might tell me that it's
bad to use a fan for some other reason.

Which way to go? Speed control on the fan to slow it down and keep
it quiet? No fan at all, because the R-390A was designed not to need
it? Some vastly more quiet and appropriate fan?

Tim. (KA0BTD)