O.K., For those of you who are beginers, you may find some interesting info at:

?????????????????????

There is some basic kit building info for those who are starting out.

For those of you who are into something a bit more deeper, Ray seems to be into ameture
radio, and has quite a bit on his site about this, plus a bit of other stuff you might find
interesting. Check it out at:

?????????????????????

If anyone else has any non comercial Electronics sites they wish to tell us all about feel
free to send the URL to the group. TAKE NOTE though, NON-Comercial. If you have any questions
about wether a site qualifies as non-comercial, send me (the moderator) the URL off list, and
I will asses it.
???

)O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(

???????????? The Sinister Dragon
???

Hey, Just because I'm EVIL,
???????????? Doesn't make me a bad person......????????? >:-)

Visit My sites at Geocities:
??? Blood Moon -
??? Little Herbal -
??? Zenit Photographic -

Join my Egroup:
??? Inverted Pentagram -
??? Zenit-EM -
???

Hello,
Well, I'll give a stab at it. I havn't actually done anything
like this but it sounds pretty simple. Off the top of my head I
would think you could take your 12V battery run it through a 5V
converter and tie the 5V and ground to the same terminal connections
as where your solar pannel connects up. I think I would also add a
diode to each line going to the solar panels, not sure on that but
seems like a good idea just in case the battery tries to overpower
the solar cells. Like I said, not sure on this idea but is sounds
good in my head.

Good luck
Michael

--- In Electronics_101@y..., markallen <markallen@m...> wrote:

Hello everybody.

I recently put together a small solar powered project. It draws

about

300ma at a regulated 5v. It runs great here in LA, but now I want

to

bring it to London. Obviously I'm going to be getting a lot less
power out of my panel. What I want to do now is attach a 12v lead
acid battery that can power the project when the sun is behind the
clouds (hopefully not all the time!). Is it complicated to power a
circuit and charge the battery at the same time? Should I try and
find an off the shelf solution to this problem, or is this

something

I can put together myself (with some help from the list)?

Any advice greatly appreciated.

Mark Allen

Can someone explain the basics of a hall effec sensor to me? I
believe if I understand correctly that they sense changes in magnetic
fields. Is that correct? If so are they sensitive enough to sense
the magnetic field that is produced by a wire that has been
energized. If not what sensor should I use for this type of
application. I am wanting to sense when a spark plug wire on a small
engine is firing and then send that back to a F-V for a read-out.

Thanks

Hi all

I am a newbie to the art of electronics so please be gentle with me :-)

I am trying to run 16 LED's from a single 12v power source. The LED specs are as follows:

Parameter Value Units
DC Forward Current[1] 30 mA
Peak Forward Current 100 mA
Average Forward Current 30 mA
Power Dissipation 120 mW
Reverse Voltage (IR = 100 mA) 5 V
LED Junction Temperature 100 ?C
Operating Temperature Range ?40 to +80 ?C
Storage Temperature Range ?40 to +100 ?C

What I would like to know is what would be the best way to hook these things up and what value resistors I would need to do it.

Cheers
Pedro



_________________________________________________________________
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Hello everybody.

I recently put together a small solar powered project. It draws about 300ma at a regulated 5v. It runs great here in LA, but now I want to bring it to London. Obviously I'm going to be getting a lot less power out of my panel. What I want to do now is attach a 12v lead acid battery that can power the project when the sun is behind the clouds (hopefully not all the time!). Is it complicated to power a circuit and charge the battery at the same time? Should I try and find an off the shelf solution to this problem, or is this something I can put together myself (with some help from the list)?

Any advice greatly appreciated.

Mark Allen

A quick rant from your freindly moderator,

????????? Just a question asked on another list that I am on, and a quick reply.
I'm posting this for the "Beginers" on the list so those of us that know
everything can of course instantly delete this post and go on with our
perfect lives.
???

???>> What is the sponge used for, I have seen people wipe the tip before
???>> and after they use it on a wet sponge?

???

????????? The sponge is used to clean the tip between soldering. When the Iron has
been standing for any period of time wilst on, a layer of oxides will form on
the
tip. Also, any flux remaining on the tip will deteriate. It is important to
remove these before the next use as it will contaminate the joint. Just to
put this into
percpective. This will perhaps have little affect on a "Tandy" flashing light
kit, that you can resolder if the joint goes bad, but might break things if
the aircraft's
computer dies. In any case I tend to have the habit of wiping my tip clean
before use whenever I'm soldering, as it is not a bad one, and though the
telecomunications equipment I work on isn't going to kill anyone if a "bad"
joint has problems, it does affect the reliabillty.

????????? Just a few words about using sponges to clean:

????????????????????? Firstly, it is a VERY comman error for people to have WAY to much
water in the sponge. If you can wring water out of the sponge you are using
then
there is WAY to much in it. When you hear of people talking about damp
sponges they mean DAMP. If you have to much water in the sponge, when the tip

touchs the sponge, it imediatly cools to below the melting point of the
solder, thus effectivly making it imposible to remove the oxidized solder,
and potentially
making the next joint soldered cold. This especially happens when the tip is
long and narrow. Sure, you have to re wet the sponge after a couple of hours,
but
this is really isn't going to hurt you now is it??

????????????????????? Second, I have seen some REALLY discustingly filthy sponges in my
time. Your sponge should be cleaned, thoughly rinsed under fresh water before

each use. (Be carefull not??? to let scrap solder go down the drain, it
contains lead don't forget) Otherwise when you wipe the tip. you end up
puting more dirt
on it than you are removing. It takes about a whole minute to do this not a
lot of time in the grand scale of things, and no time at all compared to the
time it
can take to find a dodgy joint in that prized project you've been working on
for weeks that now doesn't work.

????????????????????? Likewise I have seen sponges used WAY past their sensible used by
date. A sponge costs what, a dollar?? So why use some ratty, dog chewed peice

of crap that you wouldn't normally think twice about throwing away?? If it
starts wearing out replace it for the above reasons.

????????????????????? One final piece of advice, is only to use sponges designed for the
purpous. I dont know how true or false the info is, but sponges for this use
are suposed to
have been designed to drag a hot iron across. They can stand the heat, and
suposedly have no funny additives. I do know there are quite a few varities
of
synthetic sponge around. Alot of these have additives to help with cleaning
kitchen surfaces, and they may have low melting points. These sponges will
once
again contaminate the tip. In any case once again the proper thing just ain't
that expensive, so why take the risk.

????????? O.K. my rant is now over, I can't believe I wrote so much about tip
cleaning sponges. Maybe I need a life or something. In any case, I hope the
info was
helpfull to our beginers.......

)O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(

???????????? The Sinister Dragon
???

Hey, Just because I'm EVIL,
???????????? Doesn't make me a bad person......????????? >:-)
???
???

but cant we charge them in parallel i.e connect all the batteries in
parallel
and then apply 1.5 volts.

is configuration will require only 1.5 volts no matter how many
battries
are charged at a time.

Well, it would work, but you'd need a current source that could handle it. With batteries charging in series, you'll always deliver the same current (well...not exactly...not all batteries have the same internal resistance). One battery at 1.5V versus two batteries at 3V will give you the same current because you've doubled your resistance along with the voltage. So your power supply will only need to deliver that much current no matter how many batteries you're charging.

I'm not saying it's impossible, though, try it.

No matter how your batteries are configured, series or parallel, it's still going to be the same wattage dissipated in the power supply.

-Tavys

hi

i just got a idea yesterday and here it is.

normally we charge batteries in series i.e if we want to charge 2
batteries
of 1.5 v then we connect them is series and apply 3 v and so
on..changing
the voltages...as the no. of batteries increase.

but cant we charge them in parallel i.e connect all the batteries in
parallel
and then apply 1.5 volts.

is configuration will require only 1.5 volts no matter how many
battries
are charged at a time.

can this idea work.
please reply .
thanks.

aditya n

hi

thats very good....as a response i will say that there should be more
of practical things like simple interesting circuits which can be made
easily(i mean that the components should be available easily) and also
problems and other things(like reading a data sheet,understanding the
component numbering like 1N1007,741 etc) which arise in practical
circuits which are not given in textbooks.

text books no matter how good they are cant replace practical
experince....u see.

of course theory should be also be there but personally i am feed up
with it (doing a 4 year degree course in electronics and telecom).

aditya n

Has anyone noticed that wirewound chokes have all but disappeared from
the electronic suppliers lists these days? The omission of these and
certain other items with which I was once familiar, and the appearance
of new components like IC voltage regulators, is very disconcerting to
me, as I learned my electronics in the late 1940s and early 1950s
(before transistors) when I studied for Physics A level and the Amateur
Radio City and Guilds Institute Exam. I recently attempted to build a
small power unit with a voltage regulated smoothed output of 12V for a
model railway, but couldn't get the bl***y thing to work. However, once
I had swapped the reg. for a small transformer wired with half the
secondary winding as a choke, (Pi smoothing circuitry) I managed to
obtain the results expected. I would certainly not mind a simple
discussion of the _practical_ intricacies of transistor or IC circuitry,
as probably the more times one has the chance to absorb ideas the better
will become one's understanding.
For Info, my present interest in electronics is mostly concerned with
model railways: PSUs, Controllers for special purposes, LED projects -
lighting, miniature signs, etc., Signalling (automatic), Turntable and
Level Crossing electro-mechanical operation, Solenoids.
I am having a problem with a turntable circuit at present. I need a
double pole change over relay which will operate at circa 6V, _without
chatter_, so that I can latch it with contacts 'on' until the latching
(solenoid) circuit is broken elsewhere and thus reset. Can anyone
suggest a likely type or source?
What are the relative merits/demerits of including fuses in both the
line and neutral mains feed to a PSU and also in the +ve and -ve O/P? I
have fitted a Mains - 12VDC PSU in this way (with fuses in both) but am
having second thoughts about the safety of this arrangement if the fuse
in the neutral, or fuse in the -ve O/P should blow without corresponding
breaks in the other fuses.?
Keith Messent, Skipton, UK

One question I have for you all is: What level of electronics
are people on the list up to?? I would like to start posting some info
now that we have some members, But need to know where to start. Can I
assume that we all know the basics?? Or should I go into detail about
capacitance and resistance and REALLY basic stuff?? How about some
feedback...... It's very easy for me to forget how hard some concepts
of electronics can be to grasp, I've been working in the industry for
around tweenty years or so, though I'm no expert by a long shot... I'll
post some info I feel is intresting and not too advanced, and if it's a
bit much let me know and I'll make things a bit more basic.......

Feedback please......

)O( )O( )O( )O( )O( )O( )O( )O( )O( )O( )O( )O( )O( )O(

The Sinister Dragon

Hi. I just found this list. I'm strictly an enthusiastic electronic hobbyist.
I know the basics and like tinkering around with circuits and projects.
Frequently get lost in complicated circuit diagrams. :)
ralph

I know that people may criticize me for asking for
help on this but I am not an Electronics expert... yet.
And furthermore I don't believe in free energy. :)

I have a final project coming up for my electronics
class and the proffesor says that we have to build
something that requires sautering... it doesn't even have
to be breadboard. This project is just for fun because
my college requires a final project but my prof. likes to
base it all on a final, So the finished project does not have
to work. With those criteria in mind i though building some
type perpetual motion machine might be fun. In researching
on the net I found the easiest looking one (ie. cheapest) was

The plans are very sparse for this machine though. In your
profesional opinions is this just a hoax becasue the plans are so
nonspecific?

thanks,
awzse


_________________________________________________________
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Hi all,

???[Electronics_101] FREE CELLPHONE INTERNAL ANTENNA BOOSTERS

???????????????????????? This Member has now been removed from the list. As moderator I
will tolerate SOME advertising, But I have had several compliants about
these postings, and have given fair warning. These posts where both off
topic and comercial. Thankyou for all contributing to the group, I hope
to see the group grow further and increase discucion of electronics.

????????????????????? One question I have for you all is: What level of electronics
are people on the list up to???????? I would like to start posting some info
now that we have some members, But need to know where to start. Can I
assume that we all know the basics?? Or should I go into detail about
capacitance and resistance and REALLY basic stuff?? How about some
feedback......??? It's very easy for me to forget how hard some concepts
of electronics can be to grasp, I've been working in the industry for
around tweenty years or so, though I'm no expert by a long shot...??? I'll
post some info I feel is intresting and not too advanced,??? and if it's a
bit much let me know and I'll make things a bit more basic.......

????????????????????? Feedback please......
???

)O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(

???????????? The Sinister Dragon
???

Hey, Just because I'm EVIL,
???????????? Doesn't make me a bad person......????????? >:-)
???

Hi Everyone!

I am going to be relaunching StuckButton magazine on September 1.
Most of you know it, others won't - basically its a free magazine
(now) centered around any aspect of radio, electronics,
telecommunications and computing (well the technical (hardware) and
software fix side of computers anyway).

I'm looking for articles for the new bi-monthly magazine (now 60
pages, looks much more like a magazine should!). So if you want to
write about any of the above topics I've mentioned above (or anything
else related - just ask me), send a note to stuckbutton@...

I want as many articles as possible to keep a good collection, which
I will use as desired in certain issues (if not the first, maybe the
second - it'll get there!!!!). I won't be able to pay you anything
(it's a free magazine anyway!), but you will get all the credit you
deserve!

Photos, circuits, diagrams, cartoons, URLs, history, equipment
reviews, news items and "info snippets" etc are great also!

You can find it at:

Thanks, Dan Bartlett
StuckButton Editor-In-Chief

Accessories4U wrote:

Due to the new store promotion and advertising. We hand out FREE LCD Holograms for your cellphones.?We have over 80 kind of different of holograms for you to pick from our list:?8-BALL, AIRPLANE, ALIEN, ANGEL, AQUARIUS, ARIES, BABY ALIEN, BASEBALL, BAT, BLACK JACK, BULL DOG, BUTTERFLY, CANCER, CAPRICORN, CLOWN, COCONUT TREE, DICES, DOLLAR SIGN, DOLPHIN, DRAGON, EAGLE, EIFFEL TOWER, EYE BALL, FLAMINGO, FROG, GEMINI, GOLF, HAPPY TEDDY BEAR, HEARTS, JACK O' LANTERN, CRUCIFIX, KILLER WHALE, KINGKONG, LAPTOP, LEO, LIBRA, LIGHT BULB, LION, LITTLE FAIRY, MAN MOON, MIND, MUSICAL NOTE, MUSTANG, NASCAR, PEACE SIGN, PERSIAN CAT, PHARAOH, PIGLETS, PIRATE SHIP, PISCES, PUPPY, PUSSY CAT, COINS, QUESTION MARK, REAPER, REPTILE EYE, ROSE, SAGITTARIUS, SCORPIO, SHARK, SKIER, SKULL, SMILEY FACE, SNOW BOARDER, SNOWMAN, SOCCERBALL, SPACE SHUTTLE, SPIDER, STATUE OF LIBERTY, SUNSHINE, TAURUS, TEDDY BEAR, TIGER, TRAIN, T-REX, T-REX SKULL, TRICERATOPS, TROPICAL FISH, UFO, UNICORN, VIRGO, WIZARD, US FLAG, CANADA FLAG, SWISS WATCH

As moderator of the list, I have given this person a warning not to post advertising of this kind again. If it continues they will be asked to leave. I consider one warning sufficient.

)O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(? )O(

???? The Sinister Dragon
?

Hey, Just because I'm EVIL,
???? Doesn't make me a bad person......??? >:-)
?

Hello,

Due to the new store promotion and advertising. We hand out FREE LCD Holograms for your cellphones.

Is there some way to filter this spam crap from the list?

Bob,

There are many variables its true, but how about take any easy one.

Last time I took a common one apart it had a metal rectangle with lots
of copper wire wraped around it. How do you determine how many turns
of what gauge wire will produce the desired result.

You could use a 120vac to 12vac at 1 amp for an example with the
purpose to power a 12v light bulb drawing about 1 amp.

Larry

--- In Electronics_101@y..., "Bob" <rjgordon@f...> wrote:

I just want to know how you go about building a homemade
transformer. Thanks

It's so simple, a 3 year old could do it. On the other hand,

it's so

difficult, you'd need a engineering/manufacturing facility to do it.

Both

statements are completely true - depending on what characteristics

the

transformer has.

It is air core? Iron core? etc.

What frequency(s) does it operate on? Voltages? Currents?

How many sections or windings?

What is/are the intended load(s)?

What kind of (if any) shielding is required?

What is it's ultimate function?

And a lot more questions I'm sure.

There are as many possible configurations for a transformer as
proverbial grains of sand. So you can see, a bit more information is

needed

before anyone can give you anything close to a usable response to

your

question.

Bob

开云体育

Something cute that I found... It may or may not be off topic.

The Sex life of an Electron
by Eddie Currents

One night when his charge was pretty high, Micro-Farad decided to seek out
a cute little coil to help him discharge.

He picked up Milli-Amp and took her for a ride in his Megacycle. They rode
across the Wheatstone Bridge and stopped by a Magnetic field with flowing
currents and frolicked in the sine waves. Micro-Farad, attracted by
Millie-Amp's characterisic curves soon had her fully charged and proceeded
to excite her resistance to a minimum. He gently laid her at ground
potential, raised her frequency and lowered her reluctance.

With a quick arc, he pulled out his high voltage probe and inserted it in
her socket, connecting them in parallel. He slowly began short circuiting
her resistance shunt while quickly raising her thermal conductance level
to mil-spec. Fully excited, Milli- Amp mumbled "MHO...MHO...MHO"

With his tube operating well into class C, and her field vibrating with
his current flow, a corona formed which instantly caused her shunt to
overheat just at the point when Micro-Farad rapidly discharged and drained
off every electron into her grid.

They fluxed all night trying various connectors and sockets untill his
magnet had a soft core and lost all of its field strength. Afterwards,
Milli-Amp tried self-induction and damaged her solenoids and with his
battery fully discharged, Micro-Farad was unable to excite his field. Not
ready to be quiescent, they spent the rest of the evening reversing
polarity and blowing each others fuses.


BUT WAIT!!! Theres M O R E !

Micro was a real-time operator and dedicated multi-user. His broad-band
protocol made it easy for him to interface with numerous input/output
devices, even if it meant time-sharing. One evening he arrived home just
as the Sun was crashing, and had parked his Motorola 68000 in the main
drive (he had missed the S100 bus that morning), when he noticed an
elegant piece of liveware admiring the daisy wheels in his garden. He
thought to himself, "She looks user-friendly. I'll see if she'd like an
update tonight."

Mini was her name. She was delightfully engineered with eyes like COBOL
and a Prime mainframe architecture that set Micro's peripherals networking
all over the place. He browsed over to her casually, admiring the power
of her twin, 32-bit floating point processors and enquired, "How are you,
Honeywell?" "Yes, I am well," she responded, batting her optical fibers
engagingly and smoothing her console over her curvilinear functions.

Micro settled for a straight line approximation. "I'm stand-alone
tonight," he said. "How about computing a vector to my base address? I'll
output a byte to eat, and maybe we could get offset later on." Mini ran a
priority process for 2.6 milliseconds then transmitted 8K. "I've been
dumped myself recently, and a new page is just what I need to refresh my
disks. I'll park my machine cycle in your background and meet you inside."
She walked off, leaving Micro admiring her solenoids and thinking, "Wow,
what a global variable. I wonder if she'd like my firmware?" They sat
down at the process table to a top of form feed of fiche and chips and a
bucket of Baudot. Mini was in conversational mode and expanded on
ambiguous arguments while Micro gave occasional acknowledgments, although
in reality he was anyalyzing the shortest and least critical path to her
entry point. He finally settled on the old,'Would you like to see my
benchmark routine?' but Mini was again one step ahead.

Suddenly she was up and stripping off her parity bits to reveal the full
functionality of her operating system software. "Let's get BASIC, you
RAM," she said. Micro was loaded by this stage, but his hardware policing
module had a processor of its own and was in danger of overflowing its
output buffer, a hangup that Micro had consulted his analyst about.
"Core," was all he could say, as she prepared to log him off. Micro soon
recovered, however, when Mini went down on the DEC and opened her divide
files to reveal her data set ready. He accessed his fully packed root
device and was just about to start pushing into her CPU stack, when she
attempted an escape sequence.

"No, no!" she cried. "You're not shielded!"

"Reset, baby," he replied, "I've been debugged."

"But I haven't got my current loop enabled, and I can't support child
processes," she protested.

"Don't run away," he said, "I'll generate an interrupt."

"No, that's too error prone, and I can't abort because of my design
philosophy."

Micro was locked in by this stage, though, and could not be turned off.
But Mini soon stopped his thrashing by introducing a voltage spike into
his main supply, whereupon he fell over with a head crash and went to
sleep.

"Computers!" she thought as she compiled herself. "All they ever think
about is hex."




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adityan007@... wrote:

hi everybody

i just wanted to know what wattage soldering iron should be used for
normal electronic works (P C B ).

at present i have a jumbo size soldering iron which i use for
electrical
purposes which has a big tip.

also is there any tip sizes (if at all there are) for soldering iron
to be used for P C B because the one i have is a bit too big for??? P C
B (thats what i think).

aditya n

To unsubscribe from this group, send an email to:
Electronics_101-unsubscribe@...
???
???

Your use of Yahoo! Groups is subject to

Hi Aditya,

????????????????????? There is no easy answer to this question, it depends entirly on what
you intend to solder. How ever for the average hobiest, I would sugest
something in around the 60 to 100 Watt range as far as power is conserned.
Dependant upon which type of iron you buy there will be a huge range of
soldering iron tips. Which one you select will be nearly entirely personal
preferance. Three coman tip shapes are: Chisel, Pointy, and flat. I
personally prefer Chisel, around 2 to 5 mm at the tip. But this is becuase I
do alot of surface mount rework as a job.??? Cost is also an important factor.
No use dreaming about that $1000 dollar soldering iron with all the great
themo controls and fancy tips if you dont have the money. Personally, I
started off with a 200 watt Berko Iron with a 15mm tip 2mm diameter solder,
and bakers flux. And yes I soldered PCBs with it. Now however I use a Weller
TC-202 60W iron, with a variaty of tips. This is more than adequate for my
curent use. As an obsevration. I've been soldering for around thirty years
now, and in my experiance, practice is what counts rather than the tool. I
have seen some super educated people make a total mess with some really great
tools, and my wife is capable of doing some of the best most consistant work
I have ever seen with some real shit equipment (not mine) and no formal
training.

????????????????????? I feel the best advice I can give you however is test a few diferant
types of irons before you settle or buy one for yourself. If you have friends
with soldering irons, use thiers for a few hours if possible. Does it suit
your hand?? Can you make a good joint on a variaty of pads?? Desolder using
some desolder briad, How easy is it????? Does it do a good job with ease?? How
easy are the tips to change?? If possible experiment with differant tips, and
solder. If it's a thermostat type, (Adjustable) how easy is it to adjust?? Do
you like the controls?? You will hear all sorts of advice from all sorts of
people as to what the "Perfect iron"??? might be. However, largly I think is is
personal choice. Dont be afraid to try a few things out.
???

--
)O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(??? )O(

???????????? The Sinister Dragon
???

Hey, Just because I'm EVIL,
???????????? Doesn't make me a bad person......????????? >:-)

Visit My sites at Geocities:
??? Blood Moon -
??? Little Herbal -
??? Zenit Photographic -

Join my Egroup:
??? Inverted Pentagram -
??? Zenit-EM -
???