audio recording on IC -help wanted

[Watson A.Name - 'Watt Sun]

In article <bggfob$hv4$1$8302bc10@news.demon.co.uk>,
root@mauve.demon.co.uk mentioned...

In sci.electronics.design aurgathor <spam-me@if-you.com> wrote:
What would be a simple, but effective circuit
to completely discharge them without any
damage to them? I got a bunch of them, and
now they all have varying capacities.

I'm thinking about an 1N4001 in series with
a 33 ohm, which would drain them to about
0.7V, but I have a feeling that might be a
little too much.

Would a couple of discharge / recharge cycle
help to regain some of the lost capacity?

Probably not.
There is no real benefit in going below around 0.9V/cell or so.
You imply that you mean doing this per cell.
If this is so, it's safe, but if you do it with a battery, you
must observe individual cell voltages, and check that none approach
0V. (going to 0V isn't too bad, going below is)

I charges some AA Ni-MHs on my Rayovac universal charger and put them
in a flasher circuit. A few hours later the flasher quit. So I
pulled out the batteries and I found that one was reversed a few dozen
millivolts. What? I just charged them! I noticed that the lights
flickerwed on the charger, so I think the BOFH is now on the fritz.
So I charged the AAs on another charger and they are now working okay.

I pulled the top off the charger and found that it has a uC and a
74HC4351D along with the usual discrete parts. So i don't know if
there's anything I can do to t/s it. The PC board is grungy with
rosin and there are a lot of surface mount parts, so I need to get a
bottle of alcohol and clean it good, I guess. Anyone know anything
about this charger?

What you can do is to put them all in series, give a constant current charge
of C/10 for 20 hours or so, to make sure they are all fully charged.
Then discharge in series, checking every 50mah or so, and thereby sort the
cells by capacity, taking the lowest capacity ones out first.

This lets you roughly match sets of cells.

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[Joe Fischer]

In alt.solar.photovoltaic

Peter Bennett <peterbb@interchange.ubc.ca> wrote:
:Joe Fischer <gravity1@shell1.iglou.com> wrote:
:> There are no volt meter movements,
:
: I suppose, to be pedantic, you could say that all analog meters are
: current-operated devices. However, most meters intended to be used
: with external shunts are cleverly designed such that they draw
: sufficient current for full-scale deflection with 50 mV across their
: terminals. Meter shunts are therefore specified in terms of the
: current required to produce 50 mV across their meter connection
: points.

All electrical devices need to be specified as
to the voltage they are designed for, as any substantial
supplied voltage greater than that will burn them out.
Apparently shunt meters have been standardized,
which is always a good idea.

Joe Fischer

--
3

 

[Gregg]

Surface mount electrolytic. 100uF, 16 volts.

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
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[Jim Adney]

On Sat, 02 Aug 2003 22:22:04 GMT "aurgathor" <spam-me@if-you.com>
wrote:

"Ian Stirling" <root@mauve.demon.co.uk> wrote in message
news:bggfob$hv4$1$8302bc10@news.demon.co.uk...
There is no real benefit in going below around 0.9V/cell or so.

Does anyone know any easily obtainable (read Radio Shack ;-)
diode with a Vf of 0.85 - 0.9V?

Try a silicone PN diode in series with a Schottky. That would give you
~.9-1.0V. OTOH, I'd think that just going to .7 would be fine.

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

 

[R. Steve Walz]

Jim Adney wrote:

Try a silicone PN diode

Jim Adney jadney@vwtype3.org
------------

Silicon is the element used in solid state devices, silicone is the
plastic made with silicon as an atom in its matrix which is used in
women's phony boobs and in silcone sealant and in silcone lubricants.
Note silicon is pronounced "si-li-kahn" and silicone is pronounced
"si-li-kohn".

-Steve
--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public

 

[Dave Baker]

On Mon, 04 Aug 2003 03:51:29 GMT, "R. Steve Walz" <rstevew@armory.com> wrote:

Note silicon is pronounced "si-li-kahn"

maybe it is where you come from. We speak English over here, and it's
pronounced "sil-i-kon".

Dave

 

[ĺnřn˙mřu§]

On Mon, 4 Aug 2003 01:28:33 -0400, "Mark Jones" <127.0.0.1> wrote:

Gregg wrote:
Surface mount electrolytic. 100uF, 16 volts.

GeeK Zone * scripts * articles * forum |
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----------------------------------------
To test if it's actually bad, ya might want to use this capacitor ESR
(equivalent-series-resistance) tester:
Wow! They actually published this? With all these errors in it. How embarrassing...

 

[aurgathor]

"Fred Bloggs" <nospam@nospam.com> wrote in message
news:3F2E2DD9.6090007@nospam.com...

There are two types of cycles, exercise and reconditioning. The exercise
cycle consists of discharge at a 1C rate to 1V/cell, and the
reconditioning cycle is a discharge from 1V/cell to 0.4V/cell at a much
reduced rate. See: http://www.allegromicro.com/techpub2/cadex/index311.htm
for the effectiveness of this method.

Thanks, that's a very good link.

 

[FSMüller]

Michael (Micksa) Slade wrote:

For those who care... this is my first post to this group (I think), so
I'll introduce myself. skip the following if you don't care.

I'm a comptuer science graduate who has gotten started learning about
electronics and I got into it enough that I've also decided to start
studying it at uni. My main motive is to be able to do things like hook
a CD-ROM drive up to a C64 or design/make my own game console. I guess
I'm kinda bored of plain old computer programming and want to take my
skills in a different direction. I've gotten a bit of a start,
programming PICs and such to do stupid things like count or flash LED's
in the style of K.I.T.T.

Anyway, down to business. I have a dead computer motherboard with some
socketed chips in it that I'd like to try and play with, but web
searches etc
don't seem to get me any info on the chips. The 2 I'm curious about are
as follows:

28-pin skinny DIP (tee hee), marked:
EtronTech
Em51256C-15PL
TZ09T1003

this sounds like 32kx8 static RAM, did you try to google after 51256?

32-pin skinny DIP, marked:
ALLIANCE
AS7C259-15PC

7C.. sounds like Cypress, try theyr homepage

9503 USA

Anyone know where I can get specs on these or compatible chips? and
also, where I should be looking for them?

Mick.

 

[Michael (Micksa) Slade]

FSMüller wrote:

28-pin skinny DIP (tee hee), marked:
EtronTech
Em51256C-15PL
TZ09T1003


this sounds like 32kx8 static RAM, did you try to google after 51256?

Yeah, got references to other brand memories, one 256kx1, one 32kx8. No
pointers to actual specs.

is there a standard for pinouts etc of 32kx8 sram chips or something?

Mick.

 

[Lewin A.R.W. Edwards]

Em51256C-15PL
AS7C259-15PC

Both are high-speed SRAM, the first is probably main cache, the second
is probably cache tag.

 

[Gary Tait]

On Tue, 05 Aug 2003 12:43:52 GMT, "Michael (Micksa) Slade"
<micksa-news@knobbits.org> wrote:

FSMüller wrote:

28-pin skinny DIP (tee hee), marked:
EtronTech
Em51256C-15PL
TZ09T1003


this sounds like 32kx8 static RAM, did you try to google after 51256?

Yeah, got references to other brand memories, one 256kx1, one 32kx8. No
pointers to actual specs.

is there a standard for pinouts etc of 32kx8 sram chips or something?

Mick.

Pretty well.

 

[Don Bruder]

In article <bgp5do$glm@library1.airnews.net>,
"Dave" <dbeane@genie.idt.net> wrote:

Recently found out what "core" memory was and how it worked. Now I am
wanting to try an experiment to see if I can make use of some. Any idea as
to where one would look for old or "surplus" core memory, and maybe its
specs?

Thanks for any replies.

Dave
db5151@hotmail.com

Dunno where you can find any, but I can tell you this: It's almost
certainly going to be ***WAY*** too slow for today's hardware to cope
with.

--
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[Dave Platt]

Recently found out what "core" memory was and how it worked. Now I am
wanting to try an experiment to see if I can make use of some. Any idea as
to where one would look for old or "surplus" core memory, and maybe its
specs?

I see a number of core-memory boards up for sale on eBay... a DEC 16k
board, an HP 5060 core card, CDC/Cray boards, IBM 1401 and 360
boards... yeah, they're out there.

Core memory is sorta tricky to work with, due to the small voltages
and currents involved when you read 'em out. Getting the read, write,
and sense thresholds right is a bit of work.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[A E]

Dave Platt wrote:

Recently found out what "core" memory was and how it worked. Now I am
wanting to try an experiment to see if I can make use of some. Any idea as
to where one would look for old or "surplus" core memory, and maybe its
specs?

I see a number of core-memory boards up for sale on eBay... a DEC 16k
board, an HP 5060 core card, CDC/Cray boards, IBM 1401 and 360
boards... yeah, they're out there.

Core memory is sorta tricky to work with, due to the small voltages
and currents involved when you read 'em out. Getting the read, write,
and sense thresholds right is a bit of work.

Not to mention temperature compensation.

 

[Dave]

Dave Platt <dplatt@radagast.org> wrote in message
news:vj0a3mod1ng8cf@corp.supernews.com...

Recently found out what "core" memory was and how it worked. Now I am
wanting to try an experiment to see if I can make use of some. Any idea
as
to where one would look for old or "surplus" core memory, and maybe its
specs?

I see a number of core-memory boards up for sale on eBay... a DEC 16k
board, an HP 5060 core card, CDC/Cray boards, IBM 1401 and 360
boards... yeah, they're out there.

Core memory is sorta tricky to work with, due to the small voltages
and currents involved when you read 'em out. Getting the read, write,
and sense thresholds right is a bit of work.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Hmmm. Okay, so where do you suppose I could find those statistics?

Thanks for the pointer to eBay. I don't know why I didn' tthink of that. I
searched on Google and found an old jukebox for sale that uses core memory.
That interestes me, because I would have an entire working system at my
disposal (supposedly).

Appreciate the help.

Dave
db5151@hotmail.com

 

[Don Bruder]

In article <bgpckd$m0e@library1.airnews.net>,
"Dave" <dbeane@genie.idt.net> wrote:

Don Bruder <dakidd@sonic.net> wrote in message
news:9EVXa.8733$dk4.371091@typhoon.sonic.net...
In article <bgp5do$glm@library1.airnews.net>,
"Dave" <dbeane@genie.idt.net> wrote:

Recently found out what "core" memory was and how it worked. Now I am
wanting to try an experiment to see if I can make use of some. Any idea
as
to where one would look for old or "surplus" core memory, and maybe its
specs?

Thanks for any replies.

Dave
db5151@hotmail.com




Dunno where you can find any, but I can tell you this: It's almost
certainly going to be ***WAY*** too slow for today's hardware to cope
with.

Not too slow for what I have in mind. I want to put it into a shortwave
radio, so that it holds its programming without power.

Ahhhh... I'd say that could probably cope

--
Don Bruder - dakidd@sonic.net <--- Preferred Email - unmunged, SpamAssassinated
Hate SPAM? See <http://www.spamassassin.org> for some seriously great info.
I will choose a path that's clear: I will choose Free Will! - N. Peart
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[Mark (UK)]

Hiya!

Do they look like this:

http://www.leopardcats.com/oddities/0rlinks.jpg

They are zero ohm links in their original strip.

Yours, Mark.

Louie wrote:

Joe McElvenney wrote:

Have you checked for continuity through one because "zero-ohm"
resistor (a simple link) is a good bet? They are made that way so
that the board can be stuffed more easily.

that seems to be the consensus because it has 0 ohms in both directions.
but still i'm thinking it could be an inductor. looking on the bottom
side most of them have no intervening traces between thier solder
points, so why would they be there if they were just jumpers?

i don't have an ESR meter, so i can't tell if they're chokes or not. but
i don't know what else could they be. i know they ain't caps bacause
they read a static 0 ohms.

louie

 

[mike cook]

I remember this stuff when I started my computer studies back in '69.
We were programming in assembler and Algol on an ICL machine.
It had 8K words of core which was about as big as a kids shoe box.
I don't know how you would get that into a radio, even if you could
get hold of it.
It was beautifully made though.

 

[Dave Platt]

In article <bgpckd$m0e@library1.airnews.net>,
Dave <dbeane@genie.idt.net> wrote:

Not too slow for what I have in mind. I want to put it into a shortwave
radio, so that it holds its programming without power.

Unngh.

I think you'll find that the size of the necessary support electronics
(the pulse shapers/generators, line drivers, sense amps, etc.) is
likely to be prohibitive for that application.

If you actually want a solution which works (rather than a fun,
instructive, and maddeningly frustrating project to fiddle around
with) I'd suggest using a modern solution... a serial EEPROM, or a $2
PIC micro with onboard flash memory for code and EEPROM for data
storage, or an SRAM with a battery or supercap backup. Any of these
is going to be far less likely to visit upon you a severe case of
cerebral spasms.


--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!