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a friend of mine is looking for a weller 12 volt soldering iron and
the serch hasnt turned up anything. if any one knows where to order
on it would be a big help. 73 kb9yet

What does "rails" mean?

For example:

"5V at the rails"

"rail to rail amplifiers"

Unless I'm mistaken (I'm still learning here), the rails are the maximum and minimum voltages the amplifier can go to. Whether it's single ended or double ended (one transistor, or two doing push pull), and what the supply DC voltage is will determine this. Of course, by the time you get to the 'rails' you've really distorted your signal...but that's good, to me. Many amplifiers are more efficient and distort the least with lower outputs. I like to turn things up to eleven though. But not for guitars. Look at what your DC supply voltage is, and that's probably the peak to peak output voltage of the amplifier, though it can be less than that depending on the circuit. In fact, it probably will be.

But I may have no idea what I'm talking about.

-Tavys

What does "rails" mean?

For example:

"5V at the rails"

"rail to rail amplifiers"

"As for current delivery, most will do a few milli-amps, but
typically not near the rails"

"an opamp with a symmetric output swing at each rail"

"as long as your supply rails were properly adjusted."

"This pretty much slams the square right up to the rails"

Thanks,

JP

In a message dated 3/31/01 10:40:24 AM, Electronics_101@...
writes:

<< I think you must choose a power resistor
which can be used at high watts, because you are
driving a motor.Good-luck.. >>

The power rating of the resistor is dependent on how much current the motor
draws during operation. There's usually a spike in the current when the motor
is first turned on, because it has to overcome inertia to start moving. But
this is the resistor in the charger, correct? If so, it might not even be
connected to the motor, and more likely is some sort of current limiting
resistor to control the charge rate of the battery.

Chris

Yes you must use the resistor having the same color
codes but you must be aware of the power passing over
the resistor. I think you must choose a power resistor
which can be used at high watts, because you are
driving a motor.Good-luck..
ERDEM


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I also put it in the "Bookmarks" section of egroups/Electronics_101
along w/ another link.

Dan - you might want to stick your circuit page over there as well.

See ya.

JP

the resistor should have a set of bands in a color pattern on it, just get
one that matches that color pattern and replace.

Joshua

----
"A meow massages the heart."
Pulse 8 - aim:jkerseyVCSO

i have a black and decker 12v cordless drill and a resistor burnt out
in the charger and i need to know what kind of resistor is needed. if
anyone knows what i need please get back to me.

Hello everyone,

I have created a website, called the Public Electronics Circuit
Archive, where people can submit their own electronics circuits,
designs and ideas for others to look at, build, modify or redesign to
their heart's content.

No-one gets paid, anyone can use it, and every circuit and idea
becomes free-gratis public property, so everyone benefits.

The circuits will be categorised, (currently 13 categories from Audio
to Toys), and there is a public forum for electronics hints and tips
that spring to people's minds from time to time. I think it would be
a great addition to Ian's electronics list!

So, if you would like to take a look (no circuits yet - get
designing!!), please visit,

Thanks and Regards,

Dan Bartlett
Public Electronics Circuit Archive Webmaster

Hi Thomas, have been using EAGLE 4.01 light for quite some time. It is excellent, with extensive
symbol libraries, together with DRAFTCAD from ",
[not available in lighy or demo], but I have never used the Circuit Board part of any of them,
preferring to hardwire the one off jobs that I do from time to time, unless I would do something from a kit that includes the printed circuit board as well.

Regards, Steve

--- In Electronics_101@y..., tipf_1@y... wrote:

--- In Electronics_101@y..., "Thomas Lee Mullins" <tomleem@a...>
wrote:

Is there a book on schematic symbols? I have schematics for a
TI-99/4A and trying to create a circuit board using software from
exprespcb ( [IIRC]).

Yes, you can go into any radio shack and pick one up for about $5.
Plus some ok basic electronic books.

Thanks for the information. They are also in the Radio Shack
catalogue (I didn't think of looking until you posted your message).
They might even have them at their web site (which is
) but I didn't think of looking there
until just now.

--- In Electronics_101@y..., erdem ulukan <erdemulukan@y...> wrote:

Dear Thomas,
You can use BOARDMAKER Program to convert schematics
to a circuit board. You must modify the board because
it doesn't work properly and can't give the right
answer. But it can give a design idea :)

*ERDEM****

Where can I get BoardMaker?

I found software from
that has a program called Eagle CAD. It was free for/to hobbiest.
Have you heard about/know anything about it?

Dear Thomas,
You can use BOARDMAKER Program to convert schematics
to a circuit board. You must modify the board because
it doesn't work properly and can't give the right
answer. But it can give a design idea :)

*ERDEM****

--- Thomas Lee Mullins <tomleem@...> wrote:

Is there software that can convert schematics to a
circuit board
design? I have some schematics that I want to see if
I can make
a circuit board from (perhaps to 'recreate' the
device that
schematics are of).

__________________________________________________
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Get email at your own domain with Yahoo! Mail.

Tavys Ashcroft wrote:

Hi, I just joined this group.? I was actually thinking of starting my
own, but I found this one.? I'm taking electronics classes and
?

Hi Tavys,

????????? Good to see you join. The groups a bit quite at the moment, so send as many people as you want this way, the more the merrier, And the more we will all learn........???? Hope to hear from you shortly........

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

???? The Sinister Dragon
??????? (Moderator)
?

Hey, Just becuase I'm EVIL,
???? Doesn't make me a bad person......

Visit My sites at Geocities:
? Blood Mood -
? Little Herbal -

Join my Egroup:
? Inverted Pentagram -
?

So I'll just get right into it. I'm currently on transistor amplifiers. We haven't gotten to push-pull stuff yet, or any IC opamp stuff, so I'm sure my questions will be answered in class later. But I'm impatient.

If anyone here knows a bit more about this stuff please speak up.

If I understand this correctly, common emitter amplifiers are for voltage gain, common collector amplifiers are for current gain and impedence matching, and common base amplifiers are used for their low input capacitance and therefore better frequency response. So if I string these together, I'd just end up with both voltage and current gain with better low frequency response, right?

And for push pull stuff, do I need to have both positive and negative power supply (with respect to ground) and use both npn and pnp transistors or is there another way? With single transistor common emitter amplifier stuff I've done in lab so far I've seen the waveform distortion of a sine wave amplified to cutoff voltage, so if I put another common emitter in after this using the opposite transistor type and opposite power supply, would I get distortion spikes in the opposite direction? I'm interested in perhaps making my own audio effects circuits. I've seen lots of schematics on line, but not a lot of technical description to go with them.

That's all for now I guess. More to come.

-Tavys

Hi, I just joined this group. I was actually thinking of starting my own, but I found this one. I'm taking electronics classes and learning a lot, but have found very little tutorial information online that I find useful. I figure that as I learn stuff perhaps I could make tutorials and hopefully there's people on this list that know more about stuff than me. I've just gotten to common emitter/collector/base circuits in my semiconductor theory class, and I can't wait to get to ICs.

I'm on another list called 'benders' which is for people who are interested in modifying toys (casio keyboards, speak and spells, etc) to make sounds they were not intended to make. I may direct some of the people this way as some of the discussions on the list have gone more into the area of theory than just simple modifications to toys.

So who all is here and what do you do with electronics?

-Tavys

--- In Electronics_101@y..., "Thomas Lee Mullins" <tomleem@a...>
wrote:

Is there a book on schematic symbols? I have schematics for a
TI-99/4A and trying to create a circuit board using software from
exprespcb ( [IIRC]).

Yes, you can go into any radio shack and pick one up for about $5.
Plus some ok basic electronic books.

I'm glad to see some people joining and using the group. As you can
see, things arn't exactly super busy yet, but spread the word, I'm
sure we can get some discusion going, and thats what it's all about
after all..... Hope to get the Electronics 101 web page up and
running very soon, will have a basic tute on electronics princables
and some link in general to electronics pages of intrest........
Will speak to you all soon I hope.......

The Sinister Dragon.....
(Moderator)

Is there software that can convert schematics to a circuit board
design? I have some schematics that I want to see if I can make
a circuit board from (perhaps to 'recreate' the device that
schematics are of).

Is there a book on schematic symbols? I have schematics for a
TI-99/4A and trying to create a circuit board using software from
exprespcb ( [IIRC]).