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On Friday 17 February 2006 10:32 am, Stefan Trethan wrote:

On Fri, 17 Feb 2006 16:27:23 +0100, Dave Mucha <dave_mucha@...>
wrote:

I wanna know who paid for all those relays !

Dave

I expect some company somewhere that didn't use it, then someone got them
for free or very cheap and offered them on ebay for him to buy (or he
might have been that person skipping ebay).

Some time back I got given a box, that was kind of interesting...

Three big (and very thick) boards, each board having three rows of relays on
them, and a bunch of other stuff. One row was 24V coils, the rest were all
48V coils -- I think it was something to do with phone equipment? Each relay
has either 4 or 6 sets of double-throw contacts. The box also had a whole
mess of thumbwheel switches on the front panel, and some other goodies.

Dunno what I'm gonna do with any of that stuff, yet. :-)

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Thursday 16 February 2006 01:28 pm, rtstofer wrote:

Nobody sits down and wire wraps a few hundred chips to build a CPU.

Yeah they do. I forget where but do a search on "homebrew CPU webring" and
you'll find some people that IMNTBHO are really *crazy*... :-D

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Thursday 16 February 2006 12:29 pm, fnatmed wrote:

Also check these out ...



D=14.topic

The first couple of these look familiar, the first one in particular probably
being the site I was thinking of, having bumped into it before...

Got a couple of group 27 deep cycle batteries here that I'm working on, this
should be interesting, to see what I can do with them, since they've been
so sadly neglected.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Fri, 17 Feb 2006 16:27:23 +0100, Dave Mucha <dave_mucha@...> wrote:

I wanna know who paid for all those relays !


Dave

I expect some company somewhere that didn't use it, then someone got them for free or very cheap and offered them on ebay for him to buy (or he might have been that person skipping ebay).

ST

How about doing it with relays:



8-)

Leon

I wanna know who paid for all those relays !

Dave

--- In Electronics_101@..., Ray Drouillard <rayd@...>
wrote:

Leon Heller wrote:

How about doing it with relays:



8-)

Leon

Someone has way too much time on his hands. Someone buy this poor

guy a

Z80, for cryin' out loud! LOL



Ray

He "cheated" and used semiconductor memory. I guess 32kx8 relays is
a little impractical.

On the old Bendix Dynapath NC controls (circa 1968) they used a 300
BIT magnetostrictive delay line as a serial memory. They put pulses
into a tube containing mercury and read them out on the other end.

Richard

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On Fri, 17 Feb 2006 09:17:11 +0100, Ray Drouillard <rayd@...> wrote:

How about doing it with relays:

8-)

Leon

Someone has way too much time on his hands. Someone buy this poor guy a

Z80, for cryin' out loud! LOL




Ray

LOL, you suppose he received a few anonymous letters already with nothing in it but a z80 chip?

The static ram puts a real dampener on the monster.

ST

Leon Heller wrote:

How about doing it with relays:



8-)

Leon

Someone has way too much time on his hands. Someone buy this poor guy a Z80, for cryin' out loud! LOL



Ray





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heh. Op-amps aren't cheating. They are often the easiest way to get things done, but they aren't cheating.

My senior project had a bunch of the things. I used a few of them to take the signal from an electret mike and amplify it. Then, I used another chip for automatic gain control. Then I fed the results into a delta modulation circuit. I used an op-amp for the comparator, but it was too bloody slow. Oops... gotta replace it with a real comparator.

Then, I did some digital processing to turn the digitized voice into some pulses, and fed that into an LED. Using a TTL gate worked OK, but I ended up using a couple 2n2222 NPN transistors in darlington configuration.

So, if an op-amp will work for you, use it.

Then, I tried to use an op-amp current-to-voltage converter to amplify the signal from the PIN photo diode. Too bloody slow again. I looked up a FET amplifier circuit that's designed for the purpose. Maybe *that's* cheating. I used someone else's circuit for my project. <ahem> But they did tell us not to reinvent the wheel.


So the moral of the story is to use as much off-the-shelf stuff as you can -- and that includes already designed and tested circuit diagrams.



Ray Drouillard



Steve wrote:

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If it works, it's not cheating. Do what works for you.

It can be argued that it isn't the most elegant solution, or that it isn't the most efficient use of resources. Still, if it works, and you can do it without hiring a bunch of help that you would otherwise need, then it's the most efficient solution for you.

I have gone back and forth on the issue. A computer can do a lot that would take a pile of discretes and ICs, but you have a whole lot of overhead to carry around. I could program a 486 machine to control my Jeep's electronic fuel injection system, but who wants to boot up a computer just to take a spin? Also, if you're out there in traffic, the term "blue screen of death" takes on a whole new meaning.

So it all comes down to the design specifications and the resources available.


Ray Drouillard




lcdpublishing wrote:

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Hi friendly Moderator,
I've been working as an electronics tech for 10 years and am pretty
comfortable troubleshooting digital logic.

My weakest area is analog signals. I'd like to see some stuff on
transistors, what makes an oscillator as opposed to an amp, and so on.
Some stuff on filtering analog (audio) signals would also be nice!

dave

--- In Electronics_101@..., "ghidera2000"
<ghidera2000@...> wrote:
(snip)

Second issue is obtaining that power from the loop and this is where
I'm on shakey ground. I'm assuming that there will be enough voltage
drop across the transistor to run a 5V regulator. I have 5V LT1121's
for battery powered circuits (low dropout - only about .32 volts at
<4mA load) and quiescent current down in the fractional uA range.

(snip)

Every loop powere circuit I gave seen used a shunt regulator (usually
an integrated zener type function) to drop a constant voltage from the
loop that is used for powering the circuit. If the circuit also
regulates the current, there needs to be a current regulating device
in series with this regulator, and a current sense resistor also
inseries with the shunt regulator, although, with some versions, the
sense resistor can be inside the regulated voltage, so its drop is
measurable between the rails. An example of a shuint regulator
capable of at least 20 ma, but that can regulate with much less than 4
mA would be an LM431.

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

Hmmm.....

And here was wondering the other day why products seem to get more

crappy

all the time...

I guess I just don't see that. Other than a recently purchased
Toshiba laptop that is a real piece of crap, I haven't had any
problems with any of my electronic gadgets in a very long time.
Certainly no problem with WinXP.

I have everything from a PDA to 9 PCs to a full blown wood shop plus
all the usual suspects; TVs, microwave, DVD player, etc. It all
works and it works every day.

Oh well, i have no idea why that could be. Probably not enough

processing

power in there, needs a few more lines of code. ;-)

Well, you're using a computer to get to the forum. In the old days
it would take an envelope and a stamp.

But then, i guess you need to have a MBA these days to know good
engineering from bad enginering, right?

Absolutely! Left to themselves, engineers would never finish a
design. There would always be one more feature.

At no time in history has productivity (Gross Domestic Product /
hours worked) been higher. And, in the US, it is the highest in the
world. All due to changes in technology. It must be technology
because the people are not nearly as well educated as their retiring
parents.

So better let the MBA people decide what they prefer to sell us.

Every component has a mean time to failure. The combination of more
components always leads to a shorter total mean time to failure. I
don't do the analysis (and probably can't) but my guess is that a
one chip solution is inherently more reliable than a 50,000
transistor solution (assuming that many are required). Less power,
less heat, lower failure rate; all good reasons to use a micro over
discrete components. Kind of like your display power supply.

The problem is the programmers. "If builders built buildings like
programmers write programs, the first woodpecker to come along would
destroy civilization!"

The other day someone posted a question about making sequential
lights of one kind or another. A trivial project with a micro; a
major PITA with SCRs, UJTs and transisor flops. You mean use a
coupling capacitor between stages to get edge triggering? What's
that?

I'm not going to change anyone's view. It doesn't really matter
because this is just a hobby and I don't really care how other
people build their circuits. But, I will always use a micro if I
have the opportunity. I'm old, I'm tired and I'm lazy.

Richard

--- In Electronics_101@..., "lcdpublishing"
<lcdpublishing@...> wrote:

Hi guys,

This is one of "those" questions and I do not mean to start a battle
or flame war or any of that such nonesense.

However, the more I tinker with micros, the more I am discovering I
can do a lot with them, whereas trying to do some things with
discretes would be impossible (based on what little I know).
Somehow I am getting the feeling that using them is cheating - of
which I don't mind as long as I can achieve the end-goal - a working
gizmo!

So, I guess my question would be to those that know both (Micros and
discretes) and do you consider using micros as cheating in some way.

Again, please don't interpret this as the start of the "great
debate" between which is "right and wrong". I am a software guy
first, so I naturally would follow the path of a software solution
as I already know how.

Anyway, thoughts? Comments?

Chris

It is all about getting the job done. Certainly no one considders
using transistors cheating instead of using tubes.

Micros are not as fast descretes and digital is often not as fast as
analogue.

There are times you must use one technology over another.

but, the bottom line is to use the one that works.

Dave

Hmmm.....

And here was wondering the other day why products seem to get more crappy all the time...

Can't repair it, doesn't work half the time, fails early the other half, has a zillion of useless features nobody needs nor wants, controls so complicated over menus or 5th and 6th functions per button half the population doesn't know how to operate it, things crashing more often than a beta version of windows, .....

Oh well, i have no idea why that could be. Probably not enough processing power in there, needs a few more lines of code. ;-)
But then, i guess you need to have a MBA these days to know good engineering from bad enginering, right?
So better let the MBA people decide what they prefer to sell us.

ST

These days using a microcontroller in an electronic
circuit is the prefered method, at least in the
commercial world.

A microcontroller lowers the part count and therefore
the cost of assembly of the circuit board.

Upgrades no longer require the redesign of a circuit
to produce the "mark II" version. Now you simply
reprogram the microcontroller.

Microcontrollers allow more sophisticated features and
controls.

All round, commercial projects prefer to use
microcontrollers. Hobbyists can suit themselves, of course.

signalsnatcher

Current location - Woollongong - Steel City Australia

Interested in - improvised communication networks, cabled and wireless data transmission, telemetry, remote control and associated technologies.



___________________________________________________________
Yahoo! Photos ??? NEW, now offering a quality print service from just 8p a photo

Ah-hah! I see where your are coming from and what you mean. I also
think you answered part of my question that I didn't ask!

Here is an example that got me started with this whole mess going
back probably 9 months or so ago. I wanted to make a tachometer for
a machine and I think I poked my head in this group is to learn how
to do it. There were component solutions and micro solutions to the
problem offered to me. The micro solutions made the most sense to
me as I understood the logic. As for the component side of the
equation, one micro could do the work of several "needed" components
to accomplish the same task - thus, with the micro, the part count
would be less (based on what little I know so far).

There are somethings I have been doing lately that I can't imagine
it even being possible without a micro. This is what led me to ask
this question in the first place.

Believe me when I say, I have no preference of one over the other.
Being a "Green weenie", I would use a spark plug in a circuit if I
thought it would make the thing work in the end!

Thanks guys

Chris




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

Yes, in a way, i do think so.

A micro is in some ways a general purpose tool. It is very

complicated

because of this, and often brings with it way more complexity than

is

needed to solve the problem.

You are into machining, so i will liken it to something there.

Imagine a

person wishing to drill a hole into a piece of wood. He is not

into this

stuff and really only wants to drill this one hole. A micro is

like

getting a cnc mill for it. It will drill the hole, and much more,

but a

simple hand drill would have done the trick. it takes loads of

time to

learn to operate the mill, but once you know how to use it you can

drill

any hole there is to be drilled with it. Now, with micros, the

thing is,

the mill has become almost as cheap as the hand drill!

So you see, micros add complexity, cost, potential of failure,

effort at

writing the software, ......

If you don't know how to make the "easy" solution with a few

standard

components that need no programming using the micro is a solution

for you.

Anything that works for you, well, works for you!
But please, if you are going to sell something, don't torture the

rest of

the world with a unnecessarily complicated and impossible to

repair

solution if there's a much easier way (remember my post about

that

backlight inverter?).

IMO a good engineering solution must always be appropriate for

the

situation, and therefore must not be unnecessarily complicated,

which

micros often are for me.


So, using a micro just because you don't know the simpler way

without _IS_

sort of cheating IMO.
OTOH where a micro offers a clear advantage (useful functionality,

much

simpler circuit, reduced cost) it should be used, but not just

because you

don't know how to do without.


ST



On Thu, 16 Feb 2006 18:26:35 +0100, lcdpublishing
<lcdpublishing@...> wrote:

Hi guys,


This is one of "those" questions and I do not mean to start a

battle

or flame war or any of that such nonesense.


However, the more I tinker with micros, the more I am

discovering I

can do a lot with them, whereas trying to do some things with

discretes would be impossible (based on what little I know).

Somehow I am getting the feeling that using them is cheating - of

which I don't mind as long as I can achieve the end-goal - a

working

gizmo!


So, I guess my question would be to those that know both (Micros

and

discretes) and do you consider using micros as cheating in some

way.

Again, please don't interpret this as the start of the "great

debate" between which is "right and wrong". I am a software guy

first, so I naturally would follow the path of a software

solution

as I already know how.


Anyway, thoughts? Comments?


Chris

ROTFLMAO! I love it "a monolithic, dynamically reconfigurable,
analog/digital signal transmorgrifier"!

I never was one for following the "formal rules" to meet an "end
goal", so in the case of electronics as I am learning it, if it
works, and the smoke stays inside - it's a great big success!

Chris



--- In Electronics_101@..., "rtstofer" <rstofer@...>
wrote:

--- In Electronics_101@..., "lcdpublishing"
<lcdpublishing@> wrote:

Hi guys,

This is one of "those" questions and I do not mean to start a

battle

or flame war or any of that such nonesense.

However, the more I tinker with micros, the more I am

discovering

I

can do a lot with them, whereas trying to do some things with
discretes would be impossible (based on what little I know).
Somehow I am getting the feeling that using them is cheating -

of

which I don't mind as long as I can achieve the end-goal - a

working

gizmo!

So, I guess my question would be to those that know both (Micros

and

discretes) and do you consider using micros as cheating in some

way.

Again, please don't interpret this as the start of the "great
debate" between which is "right and wrong". I am a software guy
first, so I naturally would follow the path of a software

solution

as I already know how.

Anyway, thoughts? Comments?

Chris

It's about winning, not how the game is played! My formal

education

is primarily with discretes, like transistors and things. So, I
know a little about those devices. But, I don't prefer analog.

The

math is more than I want to deal with. Laplace, Fourier, Maxwell -

they all caused me a lot of strain in college. But I ate digital
alive. I understood latches, registers, gates, Karnaugh, Mealy

and

Moore state machines - I loved it!

My interests still lie in digital hardware design. Things I could
never dream of building with TTL are a piece of cake with an

FPGA.

Is it cheating that I use one chip, several thousand lines of code
and produce a working computer? Nope! That's the way it's done.
Nobody sits down and wire wraps a few hundred chips to build a

CPU.

I've done a project with 96 packages, I don't want to do it

again.

By the way, that was a ripoff of the original PONG game - 96 SSI

and

MSI devices.

I think the key to micro versus discrete is 'stepwise refinement'

a

term coined by Niklaus Wirth and related to computer programming.
But, it's the same in hardware. First we design something that
works; then we add features. Maybe we throw the code away and do

it

right on the second pass. But, we had something working right
away. 'Stepwise refinement'!

On some rare occasions, a project isn't fully defined right up
front. Even more rare is the possibility that the interface isn't
well known, or even linear over our region of interest. So,
certainly it makes sense to sit down and design the perfect,
minimal, discrete design. Heck, we'll probably get it right the
first time. In fact, just order the PCBs right away! Not...

Don't consider it a micrcontroller or microcomputer. Think of it

as

a monolithic, dynamically reconfigurable, analog/digital signal
transmorgrifier. That way it doesn't sound so softwareish.

Richard