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On Sat, 17 Apr 2004 13:53:45 -0000, Kenneth Smith <kensmith52@...> wrote:

What method of soldering do you use. I have done some research on
this and found many ways but none seem reasonable.
I can make the boards but have not figured a way to solder them.

Thanks
Ken Smith

method a) soldering iron - works only to a certain spacing.
method b) hot air pencil
method c) oven

method b and c require the use of solder paste, containing solder and flux.

ST

--- In Electronics_101@..., "Kenneth Smith"
<kensmith52@y...> wrote:

What method of soldering do you use. I have done some research on
this and found many ways but none seem reasonable.
I can make the boards but have not figured a way to solder them.

Thanks
Ken Smith

What do you mean, unreasonable?

You apply solder to the two pieces of metal you want to stick together.

As for the exact methods of how to hold the soldering iron, etc...it's
one of those things that could take pages to explain in words, but are
self-taught within the first few minutes if you simply TRY.

What method of soldering do you use. I have done some research on
this and found many ways but none seem reasonable.
I can make the boards but have not figured a way to solder them.

Thanks
Ken Smith

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--- In Electronics_101@..., "ghidera2000"
<ghidera2000@y...> wrote:

I forgot, the STK500 *IS* a programmer...

Yep, yep! It was convenient, so I hooked it up. It's a lot easier
than moving the ATmega between the STK500 and the breadboard.

I forgot, the STK500 *IS* a programmer...

--- In Electronics_101@..., "ghidera2000"
<ghidera2000@y...> wrote:

Call me paranoid but, that schematic shows the ISP lines going
directly to our Mega. Are you going directly from a parallel cable
to the Mega or are you using a programmer of some sort?

Directly connecting Miso/Mosi/sck/reset to the parallel port can
lead to the inadvertant escape of the all important magic smoke!

If

you feel a little adventurous, there's a simple ISP you can make,

do

basically what you have in the schematic and just add resistors.

Of course, if you're using a Pony or something, just ignore me and
I'll go away 8)

Call me paranoid but, that schematic shows the ISP lines going
directly to our Mega. Are you going directly from a parallel cable
to the Mega or are you using a programmer of some sort?

Directly connecting Miso/Mosi/sck/reset to the parallel port can
lead to the inadvertant escape of the all important magic smoke! If
you feel a little adventurous, there's a simple ISP you can make, do
basically what you have in the schematic and just add resistors.

Of course, if you're using a Pony or something, just ignore me and
I'll go away 8)

--- In Electronics_101@..., "Don Kinzer" <dkinzer@e...>
wrote:

I had a need to program some 64Kx8 Flash devices so I decided to

hook

up an ATmega16 and use it to read and write the Flash. I put
together a quick web page describing what I did including links to
schematics and code which can be found at the link below.

The AVR code was written in C and compiled using the GNU C

compiler

that is part of WinAVR. The other software component is a Win32
console app written in C and compiled using MSVC.

--- In Electronics_101@..., "upand_at_them"
<upand_at_them@y...> wrote:

Is that a power supply bolted to the top-left corner of your
breadboard, or just switches? And what's the metal post at the top-
right corner?

In the lower left corner of the breadboard there is a bracket that
holds a DB-9F connector, a momentary switch (for reset, typically), a
6mm power jack (for a wall wart supply) and a switch for the power.

In the upper left corner, an LM7805 is fastened to the aluminum base
of the breadboard (it's located just above the blue capacitor). The
regulator's input is provided by a wall wart plugged into the power
jack and it supplies power to the breadboard.

The metal post sticking up in the top left corner is a ground pin
that is attached to a banana plug which is plugged into the 5-way
binding post. The binding post is connected to ground so this pin
provides a convenient place to attach a 'scope probe ground or meter
lead, etc.

I have several breadboards set up like this and find it quite handy.

Is that a power supply bolted to the top-left corner of your
breadboard, or just switches? And what's the metal post at the top-
right corner?

Mike


--- In Electronics_101@..., "Don Kinzer" <dkinzer@e...>
wrote:

I had a need to program some 64Kx8 Flash devices so I decided to

hook

up an ATmega16 and use it to read and write the Flash. I put
together a quick web page describing what I did including links to
schematics and code which can be found at the link below.

The AVR code was written in C and compiled using the GNU C compiler
that is part of WinAVR. The other software component is a Win32
console app written in C and compiled using MSVC.

--- In Electronics_101@..., Stefan Trethan
<stefan_trethan@g...> wrote:
...

I try to avoid CNC by heavily going into SMD, limiting the drilling

to

connectors
and such. if you only convert all the 2-legged ones to smd you can

still

use your stock
of ics and special parts - but greatly reduce drill effort.

<much discussion of making PCBs and such deleted>

I was very reluctant to get into SMDs. It seemed like a bad fit for
my aging eyes and deteriorating steadiness of hand. But I made the
jump and now find the thought of using through hole stuff dismaying.
I will do anything to avoid drilling and love the simplicity of
SMDs. They are very easy to use - I feel they are easier than
through hole stuff once you get the technique down. There is lot
less mass to heat up so soldering is less damaging to the parts. I
can put a board together a lot faster as there is no bending or
cutting. Positioning the parts takes a little care but with the well
described techniques, its no problem at all.

You can also prototype with SMDs by using surfboards or making your
own equivalent.

On the subject of making PCBs or not. Its really worth the effort to
make my own. My perfboard creations were a disasster. I'd
inevitably wire it up wrong no matter how carefull I was and then
have a complete mess fixing it. With making my own boards, I still
make design errors but assembly errors are pretty much a thing of the
past for me. Plus, you get a professional looking product out of it.

Anyway, each to his own.

Phil

<
tmpl=story&cid=562&ncid=738&e=1&u=/ap/20040416/ap_on_hi_te/ambient_dis
plays>

or is this like $2 worth of parts and a good line????

It does bring up the question of indicators. With the digital age,
we are seeing more numeric indicators when qualitative is more
important quantitative. But that's nothing new...

Phil

I have no intention of doing anything with that stuff if I can help it. Sure,
the old parts are reportedly getting harder to find, I hear, but I have
plenty of parts to mess with, and while some of the newer stuff may be
exceedingly nifty, I don't see a _need_ for it. I'm not after minimum size,
and feel that overall the major thrust of SMD is convenience in manufacturing
more than anything else -- manufacturing in large quantity, which I'm not
doing.

you may be right there, one advantage is manufacturing.. but not only in large quantity,
also in small quantity it is nice if you don't need to drill holes, bend wires, cut wires.

I find it faster to use and throughhole parts are definitely going to be hard to find in the
near future. (and smd is cheaper too.. but i was told that this is no "how to do it cheap" list)

Perhaps. I don't use all that many of them, and in fact have found some in a
box that I've had for years, and never opened.

I have no such box ;-)

If you are facing working with a rather unknown pcb software, making a
layout, sending it out and paying a lot, waiting weeks... i know this makes
you use protoboards. But if you are experienced with the layout software and
have a good pcb setup you just print it out,

This assumes the use of a laser printer?

yes.

fuse it,

Are you talking about toner transfer here?

yes.

peel it,

And here?

still TT.

etch it,

Yeah, not time-consuming if you happen to have everything already set up to
use, and don't have to go through all of that process...

correct, if you have to get everything ready you might just choose not to make a board.

drill it,

Another time-consuming aspect of it, unless you have a CNC setup or similar
(something that's on my list to do).

I try to avoid CNC by heavily going into SMD, limiting the drilling to connectors
and such. if you only convert all the 2-legged ones to smd you can still use your stock
of ics and special parts - but greatly reduce drill effort.

ready. no more than an hour.

I suspect that it would take me considerably longer than that.

Only becaus you haven't set it up and are used to it.

I've been salvaging / scrapping stuff for a lot of years. :-)

me too.. need more storage space. definitely.

If it is possible without too much investment i will try to preserve the
whole frequency range. maybe i just add another direct output from the 038
with 50Ohms, you won't need high amplitude there, or dc offset.

What part would you use to do that?

a resistor. just like in the datasheet. and a bnc connector of course.
the max 038 has 3V amplitude or so on a low impedance output, and a seperate TTL out.

In a meter? First I've heard of that.

Metex has it all, but you can only adjust in steps.
they have crammed in all from Cap. meter, inductance meter, transistor, temp.,
diode, frequency, sig out, logic test,
of course all the RMS amp and volt, ohm stuff and a beeper into a standard size handheld meter...

But there are of course limitations... especially 3,5digit..
I only use it for these special functions, like the desktop meters (with LED display) more.
(fluke 8000). i also highly recommend norma meters, 4 1/2 digit, really fast and high quality..

Tell me more about this?

Counter, using a CPLD, you have a oscillator (i hope i find a more precise one some day)
and you then program your counter in there.
of course you can interchange gate and input so you get period display (you have different
gate times inside by dividers). then you can also add a counter for the thumbwheel (out of
a microwave ;-) ) and let it count n gate times (selectable) before it inverts the output.
you simply buffer the output to protect the cpld and that should be it then.

really not much difference between a counter and a programmable generator.

I have coded the counter function already, and there is still space for a generator i think.
Now i am doing the hardware (when i have time) because i want to do some tests
before continuing the programming.
It's a damn small package these cplds did came in (ebay so i couldn't select plcc).
The toner transfer works fine down to 6,66 mil (2 dots at 300dpi) but the metric spacing
of the tqfp100 leads to errors (uneven spacing).

I'm also not sure if the package can take the heating of the led current, will see.
If it doesn't work i need to scan the display and do the hardware again.

That's a key, figure out what you want to use it for first! :-)

Of course i know what i want to do with it, because otherwise i wouldn't notice a particular tool is missing.
I just don't want to cut corners and then have to make a new unit next week when i need other
functions.


ST

I have a few XR2206 chips around. Dirt simple. The signal generator I
use the most is based on an XR2206. It's an ugly thing but it always
does what I want and can sweep over a couple of decades. It has AM and
FM inputs.

this was the other chip i meant... i think this one is good to 1Mhz?

Do you have a schematic of the thing and want to provide it?


ST

On Friday 16 April 2004 01:50 pm, Stefan Trethan wrote:

<...>

The design was fun, I used an op amp and provided for a variable DC
offset in there. Also a logic-level output for sending slower pulses into
TTL. The board was one of those plug-in boards (44-pin edge connector)
sold for prototyping work. I've been messing with this stuff for a *long*
time and STILL haven't seen the need to make boards for stuff, unless I
was going to do a lot of some particular circuit, and it hasn't worked
out that way.

That only depends on how well your process is set up. I tended to make
circuits without prined boards in the past, but now it is not really more
time demanding to make a board, and it is really much more convenient.

I don't tend to see it that way. And making a circuit-specific board is fine
if you have a design that's nailed down, and you know it's going to work as
it is. I was fiddling with things and changing things as I went along...

also you can hardly use smd on those proto boards.

I have no intention of doing anything with that stuff if I can help it. Sure,
the old parts are reportedly getting harder to find, I hear, but I have
plenty of parts to mess with, and while some of the newer stuff may be
exceedingly nifty, I don't see a _need_ for it. I'm not after minimum size,
and feel that overall the major thrust of SMD is convenience in manufacturing
more than anything else -- manufacturing in large quantity, which I'm not
doing.

(And i can make boards cheaper than buying the proto boards)

Perhaps. I don't use all that many of them, and in fact have found some in a
box that I've had for years, and never opened.

If you are facing working with a rather unknown pcb software, making a
layout, sending it out and paying a lot, waiting weeks... i know this makes
you use protoboards. But if you are experienced with the layout software and
have a good pcb setup you just print it out,

This assumes the use of a laser printer?

fuse it,

Are you talking about toner transfer here?

peel it,

And here?

etch it,

Yeah, not time-consuming if you happen to have everything already set up to
use, and don't have to go through all of that process...

drill it,

Another time-consuming aspect of it, unless you have a CNC setup or similar
(something that's on my list to do).

ready. no more than an hour.

I suspect that it would take me considerably longer than that.

And you have the benefit that it looks really good.

That's not a particularly relevant factor for me.

I didn't see that as being useful in what I intended to be an item of
bench test equipment. For a musical instrument, yeah, but that would be
a different project then.

I want it as a test bench item. I used the frequency sweep in the past to
make quick and easy bode plots (amplitude).

Ok, I can see where that would be useful. Maybe.

Of course i can live without but if i can include it.. well..
most of the commercial generators have f sweep so it might be a good idea.

(I agree the amp. modulation is maybe less useful but i can imagine uses
if i try hard)

That would take a very fast and expensive op amp, to be sure. Why go
up that high in terms of frequency? When I get up there I usually want
some fixed frequency and will likely use one of those crystal oscillator
modules I have a pile of here.

I don't have a pile of crystals just now.

I've been salvaging / scrapping stuff for a lot of years. :-)

If it is possible without too much investment i will try to preserve the
whole frequency range. maybe i just add another direct output from the 038
with 50Ohms, you won't need high amplitude there, or dc offset.

What part would you use to do that?

Seems like a good idea to do that, and much easier if i can keep the amp.
slow.

Yes.

What are you going to use it for that you want to go all the way up to
20 MHz?

I need a generator, i have none.. all i have is a 1Hz to 5kHz generator in
a multimeter, TTL.

In a meter? First I've heard of that.

I'm on a tight budget so all is moving between homebrew and ebay....

I've also had little to spend on this sort of thing most of the time.

You see i don't need the 20Mhz now, since i obviously don't know how to
design 20Mhz circuits ;-).
But who knows what exactly the future will bring, things are definitely
going faster and faster.

Yeah, well, just because computer speeds are getting up into the UHF range
doesn't mean that I'm going to take my hobby endeavors there, I'm happy
enough to work with audio...

I'm thinking about adding a ttl out the the counter i am just programming,
i have a fast crystal in there already, a thumbwheel encoder and a 8 digit
display so i reckon it is not hard to allow for using the counter the other
way around. This will satisfy all need for high frequency clock signals,
precise and TTL.

Tell me more about this?

So if it works out i only need the generator for sine and higher amplitude
things.

That's a key, figure out what you want to use it for first! :-)

thanks for making me think about what makes sense to build and what not,
sometimes i overshoot the target.

It's easy to do when you're sitting there playing with ideas, and lose track
of what you would or wouldn't do with most of those features.

I am just not seeing the reactive component; the TRIAC does not cause
a phase shift in the relationship between voltage and current. I think
only the load can do that.

maybe there is none..

but if i look at the current at the input the maximum of the current is on a other
time than the maximum of the voltage. i would define that as phase offset.

ST

--- In Electronics_101@..., "Murat Ceylan" <hector@g...>
wrote:

Hello Everyone,

I'd like to build a signal generator that is not too professional

but good

enough for general use i.e. that can produce sine, sawtooth and square
waveforms in 1-50kHz range or so with reasonable reliability. Do

you happen

to have any schematics, suggestions, assembly tips etc.?

Many thanks in advance,
Murat

--
NEU : GMX Internet.FreeDSL
Ab sofort DSL-Tarif ohne Grundgebühr:

I have a few XR2206 chips around. Dirt simple. The signal generator I
use the most is based on an XR2206. It's an ugly thing but it always
does what I want and can sweep over a couple of decades. It has AM and
FM inputs.

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--- In Electronics_101@..., Stefan Trethan
<stefan_trethan@g...> wrote:

A TRIAC is a switching device which will generate harmonics in the
power drawn from the mains. Some of the power may be reactive power
but most is real power that light your bulb. The voltage and current
are both in phase even if waveform is a distorted.

No, the main voltage is not distorted. if you measute before the triac
there is a phase offset for every phase angle not 0 or 2*pi (more or

less).

I am just not seeing the reactive component; the TRIAC does not cause
a phase shift in the relationship between voltage and current. I think
only the load can do that.

I doubt you get the intersil part for free so why bother?

Because this was a bunch of years ago, when the parts you refer to weren't
available, and I doubt that I could've gotten it for free anyhow. Not that
it was all that expensive, it was sold at Radio Shack for a while and
could't have been more than a couple of dollars.

sure, i only want to say the max038 costs some eur30 to 50 or so if you buy it,
and the interesil much less, but if you can get the maxim for nothing this is no
problem.

The design was fun, I used an op amp and provided for a variable DC offset in
there. Also a logic-level output for sending slower pulses into TTL. The
board was one of those plug-in boards (44-pin edge connector) sold for
prototyping work. I've been messing with this stuff for a *long* time and
STILL haven't seen the need to make boards for stuff, unless I was going to
do a lot of some particular circuit, and it hasn't worked out that way.

That only depends on how well your process is set up.
I tended to make circuits without prined boards in the past, but now it is not
really more time demanding to make a board, and it is really much more convenient.

also you can hardly use smd on those proto boards.
(And i can make boards cheaper than buying the proto boards)

If you are facing working with a rather unknown pcb software, making a layout,
sending it out and paying a lot, waiting weeks... i know this makes you use protoboards.
But if you are experienced with the layout software and have a good pcb setup you just
print it out, fuse it, peel it, etch it, drill it, ready. no more than an hour.

And you have the benefit that it looks really good.

I didn't see that as being useful in what I intended to be an item of bench
test equipment. For a musical instrument, yeah, but that would be a
different project then.

I want it as a test bench item.
I used the frequency sweep in the past to make quick and easy bode plots (amplitude).
Of course i can live without but if i can include it.. well..
most of the commercial generators have f sweep so it might be a good idea.

(I agree the amp. modulation is maybe less useful but i can imagine uses if i try hard)

That would take a very fast and expensive op amp, to be sure. Why go up that
high in terms of frequency? When I get up there I usually want some fixed
frequency and will likely use one of those crystal oscillator modules I have
a pile of here.

I don't have a pile of crystals just now. If it is possible without too much investment
i will try to preserve the whole frequency range. maybe i just add another direct
output from the 038 with 50Ohms, you won't need high amplitude there, or dc offset.
Seems like a good idea to do that, and much easier if i can keep the amp. slow.

What are you going to use it for that you want to go all the way up to 20 MHz?

I need a generator, i have none.. all i have is a 1Hz to 5kHz generator in a multimeter, TTL.
I'm on a tight budget so all is moving between homebrew and ebay....

You see i don't need the 20Mhz now, since i obviously don't know how to design 20Mhz circuits ;-).
But who knows what exactly the future will bring, things are definitely going faster and faster.

I'm thinking about adding a ttl out the the counter i am just programming, i have a fast
crystal in there already, a thumbwheel encoder and a 8 digit display so i reckon it is not
hard to allow for using the counter the other way around.
This will satisfy all need for high frequency clock signals, precise and TTL.
So if it works out i only need the generator for sine and higher amplitude things.

thanks for making me think about what makes sense to build and what not, sometimes i overshoot the target.

ST