audio recording on IC -help wanted

[Tim Hubberstey]

elehman1@columbus.rr.com wrote:

I am working on a circuit that calls for a MM5837N noise generating IC chip.
This is an obselete chip and I need to find a chip that can take its place.

Any help in locating an alternate chip would be great.

This chip is nothing more than a 17-bit LFSR with an internal oscillator
running at somewhere between 55 and 120 kHz. This is easily replicated
with almost any of the small CPLDs available (you'd need an external
clock). You could probably also program it into one of the 8-pin PIC
devices if you need to keep the same size footprint.

You can get a data sheet here:
http://www.alldatasheet.com/datasheet-pdf/pdf/NSC/MM5837N.html
--
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . . VHDL, ASICs, FPGAs, embedded systems
Vancouver, BC, Canada . . . . . . . . . . . http://www.marmot-eng.com

 

[Leon Heller]

"Tim Hubberstey" <bogus@bogusname.com> wrote in message
news:mxNDd.4230$06.421@clgrps12...

elehman1@columbus.rr.com wrote:
I am working on a circuit that calls for a MM5837N noise generating IC
chip.
This is an obselete chip and I need to find a chip that can take its
place.

Any help in locating an alternate chip would be great.

This chip is nothing more than a 17-bit LFSR with an internal oscillator
running at somewhere between 55 and 120 kHz. This is easily replicated
with almost any of the small CPLDs available (you'd need an external
clock). You could probably also program it into one of the 8-pin PIC
devices if you need to keep the same size footprint.

Here is a noise generator program for the ATtiny11 AVR:

http://www.dvanhorn.org/Downloads/T11-Noisy.zip

It works very well.

Leon

 

[Watson A.Name - \"Watt Su]

"Michael" <NoSpam@att.net> wrote in message
news:41D88680.44116BFF@att.net...

"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:
Last week I tossed out a couple AST Ram 3000 cards with a meg of
them on
each board. Sorry.


Isn't that the way it always goes? It's happened to me before ....
and
the other way around too.

A few days ago I was cleaning out some more stuff, and I found 9 of
these chips. I'm not sure if they're the same thing. I think they're
from an old video card.

Mt4C256-7 The Mt means Micron Technology, IIRC. They're 70 nS chips in
a 20-pin DIP package. Date codes in early '92.

If you think they'll work, contact me at alondra101@hotmail.com and
include NOSPAM in the subject: line or i'll never see the email.

 

John Atwood wrote:

Allen Michielsen <amichiel@servtech.com> writes:
I am looking for a source in the US to Mail Order a few Intel 80486

(33 or 66 Mhz) CPU's. I found a place which had them for $12 ea,
but
I lost the address. Compared to that, Jameco is a bit pricey at
$40.
They could be new, used, or pulls, it doesn't matter.

T Hakemack <haksauto@fbtc.net> wrote:
www.comp-recycle.com has them 33=15.00 66=35.00

Any happy customers of comp-recycle out there? They have some
things I'd like to buy, but a web search turned up one unhappy
customer at: http://www.internet-club.com/usa/pezz/

I'll cc the company to give them a chance to respond.


John

 

Yes, I bought a motherboard from them for a Compaq laptop. The board
had been fixed and I was skeptical about using it. I wrote at least 100
emails asking for a guarantee before I plugged it in and it burned it
up. I got no reply. So, I went ahead after 3 weeks and installed the
card, and it was no good. I have been trying to get in touch with them
since with no luck, this has been going on since October, 2004. DO NOT
DO ANY BUSINESS WITH THEM... good luck , jim
John Atwood wrote:

Allen Michielsen <amichiel@servtech.com> writes:
I am looking for a source in the US to Mail Order a few Intel 80486

(33 or 66 Mhz) CPU's. I found a place which had them for $12 ea,
but
I lost the address. Compared to that, Jameco is a bit pricey at
$40.
They could be new, used, or pulls, it doesn't matter.

T Hakemack <haksauto@fbtc.net> wrote:
www.comp-recycle.com has them 33=15.00 66=35.00

Any happy customers of comp-recycle out there? They have some
things I'd like to buy, but a web search turned up one unhappy
customer at: http://www.internet-club.com/usa/pezz/

I'll cc the company to give them a chance to respond.


John

 

[Al]

In article <VaFFd.196682$8G4.46247@tornado.tampabay.rr.com>,
"mlk" <mcguyver@cfl.rr.com> wrote:

Help needed

Does anyone have a simple PIC / video sync / genlock circuit for on screen
display or video overlay of some small graphics and text overlaid on NTSC
video or (RS-170). There are commercial IC's from Maxim, ST micro, TI, but
most are obsolete. I know this can be done, just need the source code and
schematics, any help appreciated.

Mitch

This is what you need: http://www.decadenet.com/bob2/bob2.html

Al

 

[Graham W]

Erik Walthinsen wrote:

I've got a circuit based on a ATtiny15L and Honeywell's HMR3100
compass module that appears to have only one remaining problem before
I'm done with it. If the circuit is hooked up to a bench power
supply, which is powered on with its front switch, the compass fails
to initialize properly, and the circuit doesn't do its job. This is
obviously due to a slow ramp-up of supply voltage/current from the
bench supply. If the power is stable and a switch applies power to
the target circuit, it works every time...
...
I could probably build a retrofit module with a regulator, on-board
cap (currently 33uF on either side of the regulator), and supervisor
chip connected to a mosfet/etc, but I'd really rather not have to do
that, as that almost guarantees surface-mount parts.

Try using 2u2F for those regulator caps.


--
Graham W http://www.gcw.org.uk/ PGM-FI page updated, Graphics Tutorial
WIMBORNE http://www.wessex-astro-society.freeserve.co.uk/ Wessex
Dorset UK Astro Society's Web pages, Info, Meeting Dates, Sites & Maps
Change 'news' to 'sewn' in my Reply address to avoid my spam filter.

 

[KILOWATT]

Thanks a lot Fritz for your very informative reply...was appreciated.
I discovered that i was wrong with units... millicandelas stand
for"mcd"...not microcandelas! ;-) Since my OP, i've dicovered this
interesting site that many are (you?) aware of:
http://ledmuseum.home.att.net
Thanks again and for any future replies

--
Alain(alias:Kilowatt)
Montréal Québec
PS: 1000 excuses for errors or omissions,
i'm a "pure" french canadian!
Come to visit me at: http://kilowatt.camarades.com
(If replying also by e-mail, remove
"no spam" from the adress.)

 

[Mike Harrison]

On Thu, 27 Jan 2005 21:01:24 -0700, "Fritz Schlunder" <me@privacy.net> wrote:

"legg" <legg@nospam.magma.ca> wrote in message
news:944jv0h42j87qd6rejrfqa7lm2qqoeb0iv@4ax.com...
On Thu, 27 Jan 2005 10:29:28 -0000, "Mike Deblis"
mdeblis@hotmail.com> wrote:

Hi,

I'm looking for a 200 - 250V FET with low Qg, low RDSon (only needs maybe
3A
peak Ids, but low RDSon for efficiency) and LOGIC LEVEL GATE for use in
an
SMPS that only has a 9V supply - the SMPS is in boost configuration to
give
180V @ 20mA out, probably going to use the LTC1872 if I can.

Any ideas would be appreciated - I've not had a lot of luck so far - I
know
its a tall order. An SMD footprint would also be good.

Siliconix Si4490DY Nchannel 200V 0R09 in SO8, is characterized with
6Vds.

http://www.vishay.com/doc?71341

RL


Hey now that is an interesting part. I wonder how much it costs...

http://www.ebv.com/en/inventory_search/stock_search.html?dummysubmit=dummysubmit&search=si4490
0.75 Euro

Farnell have stock at GBP1.12 1-off Order code 4528347

 

[Fritz Schlunder]

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:10vkeso61o4pl2e@corp.supernews.com...

Some submini incandescents are rated for over ten thousand hours.

Unfortunately at less than something like three lumens per watt.

So a tungsten filament runs hotter. Yeah, so. LEDs are far more
immune to
physical shock than incandescant lamps, so the manufacturer isn't in
any way
lieing about their product here. It is true.

It is _not_ true that LEDs will handle heat better than an incandescent,
as the ad implied.

Oh right. Yeah I glossed over that part of their statement. Yeah LEDs
don't handle temperature extremes better than incandescent. In fact they
handle high temperatures much worse, while low temperature extremes are
pretty immaterial since neither have any problems with any reasonably low
temperature.

 

[Kim Clay]

On Fri, 28 Jan 2005 18:01:54 -0800, "aurgathor" <spam-me@if-you.com>
wrote:

"Kim Clay" <kimclay@myrealbox.com> wrote in message
news:c4jjv0hc94hi6mamo3ui5pomt1qr85s298@4ax.com...
On Thu, 27 Jan 2005 11:41:56 -0800, "aurgathor" <spam-me@if-you.com
wrote:

Yesterday I started to charge a car battery that was sitting unused
for quite a while with a 1A charger. (my other one is broke)
Initially, the battery was around 6V,
Three discharged (but not completely) cells = 6V, the other three cells
are at 0.0V each due to internal shorts.

That is not correct.
It is correct! Your original question was about a car battery that had

been "sitting unused for quite a while" which you measured at "around
6V".

A discharged battery can go down that much,
or even more without the cells having internal shorts.
Yes, one can deeply discharge a "good" battery down to 0.0V & after

the load is removed the cells _may_ recover. A new battery discharged
accidently to 0.0V & promptly recharged will probably be OK. A old
battery discharged in the same way may not make it.
The one key point is that the battery is not left in the discharged
state for long. Once the load is removed the cells start to recover. A
non-defective battery will bounce back (even without any charging
applied) to around 11-12V within 24 hours & probably less. I have never
timed it

Case in point,
a couple daysbefore this one I had a battery that measured 1.7V!
(in car, with a light left ON). In a couple of days, that battery was
measuring 14V, and worked just fine. I just checked it today --
12.85V.
Ran the battery down & it got promptly recharged.

Based on the voltage measurements after a few hours of charging
(10.40V -> 8.40V -> 6.40V) some cells must've become shorted
during the charging process.
The cells were shorted from the beginning. These are not 0.0 ohm

internal shorts but some higher resistance that have bridged the plates.
It seems your ~1A charger was enough to overcome the internal cell
short (or bridging resistance) of two of the cells but not the third.
This resulted in the 10.40V reading early in the charging process.
During the rest of the charging process the internal shorts within the
other two cells slowly decreased in value resulting in your 8.4V reading
& the ending 6.4V.

Alas, I no longer remember the voltage
after the first 10 - 15 mins of charging -- that may have been close to 12V.
Indeed it may have been "close to 12V" near the start. If the charger

can overcome the internal short a cell will attempt to recharge. The
plates just fell apart & created a harder short. It took a while for all
three cells to end up the same way - hard short internally.

Because (from your first sentence) "battery that was sitting unused
for quite a while". Car batteries self discharge just sitting on the
shelf. A discharged battery that sits is quickly self destructing
internally, as you have found out.

I expected sulfation, and while that's no good either, it's less
deadly, and it's easier to reverse than an internal short.
If you have a lead acid (12V) battery that is at ~10.5V or better it

has a chance of becoming useful no matter how long it has set. If it is
<10.5V it may (probably) have a shorted cell. These are measurements
taken of an unknown battery that has been sitting for >24 hours.

I guess material fell from the plates, created a highly conductive
sludge in the bottom, and that's what shorted the cells out.
You were attempting to recharge a battery in which 3 cells already had

internal shorts (or the battery would have been closer to 12V to start
with). These cells had been in this condition for an unknown length of
time. The shorts just became more solid as the charging progressed.

One of my friend got a 100A or so charger, so I wonder if
I can blow the shorts with that. ;-) Of course, I'd need to
find a good enough container first incase the whole battery
blows.

Even if you could magically make the shorts disappear the basic

trouble is still there. The cells are falling apart internally.

Kim

 

[Scott Goss]

Here's a pic in case it helps...

-Scott

On Sat, 29 Jan 2005 06:56:08 GMT, Scott Goss
<scott.goss@earthlink.net> wrote:

I have a BYTEK S15-F Multiprogrammer, but cannot find a source for
manuals/software. Does anyone know where these can be downloaded, or
does anyone have originals they could copy for me? I'd really
appreciate it and I would be more than willing to paypal you a few
bucks for your trouble.

Please use scott.goss <at> earthlink.net if replying as I don't check
this group all the time.

Thanks, Scott

 

"aurgathor" <spam-me@if-you.com> wrote:

One of my friend got a 100A or so charger, so I wonder if
I can blow the shorts with that. ;-) Of course, I'd need to
find a good enough container first incase the whole battery
blows.

What's a new battery cost versus the risk of battery explosion?

 

[Bill Carson]

"Erik Walthinsen" <omega@pdxcolo.net> wrote in message
news:ct6dpv0muq@enews2.newsguy.com...

I've got a circuit based on a ATtiny15L and Honeywell's HMR3100 compass
module that appears to have only one remaining problem before I'm done
with it. If the circuit is hooked up to a bench power supply, which is
powered on with its front switch, the compass fails to initialize
properly, and the circuit doesn't do its job. This is obviously due to
a slow ramp-up of supply voltage/current from the bench supply. If the
power is stable and a switch applies power to the target circuit, it
works every time...

Now, the problem is that the ATtiny15L is fully utilized: no free pins
and almost all code space used (think 1010 out of 1024 bytes).
Compounding this, the HMR3100 does not have an external reset pin...
Therefore, I need to find a way to make sure that the compass does not
get power until the supply is stable.

However, the entire design is currently through-hole, and needs to stay
that way for assembly purposes (it's really small and assembled by hand
in really small quantity). Therefore I'd like to find a part to replace
the standard 7805 regulator that will solve the problem.

Basically, I'm after a TO-220 or TO-92 (or equiv 3-terminal) voltage
regulator that will not enable its output until it can guarantee
sufficient supply current to bring the regulated rail up immediately.
Complicating this is the requirement that the regulator be able to
operate with a supply voltage up to 36V...

I could probably build a retrofit module with a regulator, on-board cap
(currently 33uF on either side of the regulator), and supervisor chip
connected to a mosfet/etc, but I'd really rather not have to do that, as
that almost guarantees surface-mount parts.

Any component suggestions would be appreciated, as would any other ideas
on how to solve this. Then again, the problem may be made moot sometime
today by way of product requirements being clarified (will a bench
supply ever be used in the field [think middle of nowhere] with that
particularly unlikely turn-on sequence?), but I'd rather have a solution
available if not.

Would the snap-on/ snap-off capabilities of the National LP2957 do the
trick?

http://www.national.com/pf/LP/LP2957.html

But, might not handle the 36 volts in.

HTH,

B.C.

 

[Kim Clay]

On Thu, 27 Jan 2005 11:41:56 -0800, "aurgathor" <spam-me@if-you.com>
wrote:

Yesterday I started to charge a car battery that was sitting unused
for quite a while with a 1A charger. (my other one is broke)
Initially, the battery was around 6V,
Three discharged (but not completely) cells = 6V, the other three cells

are at 0.0V each due to internal shorts.

that jumped to over
15 when I connected the charger, but dropped in about 30
seconds to around 10V after the oxide layer broke down.
A couple of hour later I measured the battery, and it was around
10.40V, low enough that I was wondering if it had a shorted cell.
The three non-shorted cells are taking a charge (3*2.2V= 6.6V). One

cell still has a hard short. The other two cells are charging (from
0.0V) somewhat faster than they were discharging (as they were/are
shorted internally or they wouldn't have started out at 0.0V).

Then I measured it again before going to bed -- 8.50V!!.
Three non-shorted cells are taking a charge (3*2.2V= 6.6V).

Now two cells have an internal short that your ~1A charger can not
overcome & other cell is closely behind (trying to internally short your
~1A charge).

This morning -- 6.50V, and the charger was too hot to touch,
and I disconnected the charger at this point.
Three cells partially/fully charged & the other three cells fairly

solidly shorted.
You started off with 3 discharged cells & 3 shorted cells. You ended up
with 3 charged cells & 3 shorted cells.

I've never seen anything like this. I figured since the charger can
supply so little current (was 850 mA @ 8.5V) there's no way it
can overcharge or damage a car battery.
It didn't damage the battery - the battery was defective before you

started charging it

I know something isn't
right since after a day, even with a wimpy charger like that it should
read more than 6.5V. Any idea what's happening? How did the
cells become shorted,
Because (from your first sentence) "battery that was sitting unused

for quite a while". Car batteries self discharge just sitting on the
shelf. A discharged battery that sits is quickly self destructing
internally, as you have found out.
A _fully_ charged battery that is in good condition _may_ sit on the
shelf for 6 months or more & still function OK when put into service. It
is not good for it!! At least put it on a charger once a month to top
it up. There are _much_ better ways to store a battery - as on a float
charger.

if that's the case? (the battery wasn't moved
or jarred since charging began)

Take a look at the "CAR AND DEEP CYCLE BATTERY FAQ" at
http://www.uuhome.de/william.darden/index.htm for all the good info
.

TIA

Kim

 

[mc]

Can you make your own crystal oscillators? Custom-made individual crystals
are abundant, of course, and always will be, as long as there's such a thing
as ham radio.

What does International Crystal (in Oklahoma City) offer these days?

 

[Johnboy]

Fox Crystals? Jan Crystals

"mc" <mc_no_spam@uga.edu> wrote in message
news:4206ce8e@mustang.speedfactory.net...

Can you make your own crystal oscillators? Custom-made individual
crystals
are abundant, of course, and always will be, as long as there's such
a thing
as ham radio.

What does International Crystal (in Oklahoma City) offer these days?

 

[Richard H.]

larwe@larwe.com wrote:

However, I've run out of unwanted boards and chips. I'd be interested
in acquiring any unwanted, non-functional *cheap* devices and scrap
PCBs that have appropriate land patterns on them. I'm mainly interested
in TSOP, TSSOP, TQFP/PQFP/MQUAD (44 through 208 pins), but I'm also
curious about MELF and similar packages.

I can't say if they meet your definition of cheap, but these guys offer
dummy components - good for practice work and testing land patterns:
http://www.practicalcomponents.com/

ISTR they're about $1/chip, with a minimum purchase of ~$60. They offer
practice boards, but you'll probably find that running your own batch is
cheaper.

Richard

 

[John Doe]

<William P.N. Smith> wrote in message
news:n0snv01gl5966adpn9v092dchlm6k56agk@4ax.com...

"aurgathor" <spam-me@if-you.com> wrote:
One of my friend got a 100A or so charger, so I wonder if
I can blow the shorts with that. ;-) Of course, I'd need to
find a good enough container first incase the whole battery
blows.

What's a new battery cost versus the risk of battery explosion?

Cost doesn't really come into this equation.... ;-)

And as I've said, I won't try this without a container that can
safely hold an exploding battery.

 

"John Doe" <spam@sucks.com> wrote:

And as I've said, I won't try this without a container that can
safely hold an exploding battery.

That you believe will, probably, as far as you know, maybe not cause
anyone any bodily injury, you hope. Have fun...