Chip with simple program for Toy

[Lord Garth]

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:X2Xae.25888$AE6.11870@tornado.texas.rr.com...

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

How come the full cost of a programmer and the micro's entire learning
curve gets factored in every time a micro is mentioned as a solution?
It's a one time cost, just like the rest of anyones test equipment or
education. I spent less than $75.00 on my programming hardware and the
dev tools were free from Microchip. My scope cost me more than $400
fifteen years ago and it was used then. Nobody worries about the
thousands of dollars needed for the rest of the stuff you need to
effectively tinker in electronics, just the $50 for the programmer like
it's some kind of major show-stopper. IME, debugging time for this
project would be virtually non-existent and the end result would be more
useful since it would have a much greater dynamic range on the time
constant.

As was mentioned here long ago, and is still true, "Use a PIC" is much too
generic of a 'solution'. It doesn't teach much about electronic hardware
and of those that suggest a PIC as a solution, maybe one has followed
through
with schematics AND source code.

Look at the PIC question today, the OP asks why the software he DL doesn't
see the programmer he built. He links a page but we don't have a clue if he
etched a PCB of space wired the thing. He has not gotten back with any
updates. It's typical.

 

[Anthony Fremont]

"Lord Garth" <LGarth@Tantalus.net> wrote in message
news:1vXae.459$m85.345@newssvr30.news.prodigy.com...

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:X2Xae.25888$AE6.11870@tornado.texas.rr.com...

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

How come the full cost of a programmer and the micro's entire
learning
curve gets factored in every time a micro is mentioned as a
solution?
It's a one time cost, just like the rest of anyones test equipment
or
education. I spent less than $75.00 on my programming hardware and
the
dev tools were free from Microchip. My scope cost me more than $400
fifteen years ago and it was used then. Nobody worries about the
thousands of dollars needed for the rest of the stuff you need to
effectively tinker in electronics, just the $50 for the programmer
like
it's some kind of major show-stopper. IME, debugging time for this
project would be virtually non-existent and the end result would be
more
useful since it would have a much greater dynamic range on the time
constant.


As was mentioned here long ago, and is still true, "Use a PIC" is much
too
generic of a 'solution'. It doesn't teach much about electronic
hardware
and of those that suggest a PIC as a solution, maybe one has followed
through
with schematics AND source code.

I know that I have provided PIC code for more than one person on usenet.
Whenever I suggest using a PIC to someone, you can consider it a given
that I intend to help them with their code and circuitry if they choose
to try it.

Look at the PIC question today, the OP asks why the software he DL
doesn't
see the programmer he built. He links a page but we don't have a clue
if he
etched a PCB of space wired the thing. He has not gotten back with
any
updates. It's typical.

Given the circuit he chose to build, I'm not surprised that it doesn't
work. I would agree that it's "typical" of a good many newbie posts
regardless of whether they're using a PIC. At any rate, his problem has
nothing to do with a PIC chip, yet.

 

[Lord Garth]

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:9hYae.25898$AE6.3605@tornado.texas.rr.com...

"Lord Garth" <LGarth@Tantalus.net> wrote in message
news:1vXae.459$m85.345@newssvr30.news.prodigy.com...

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:X2Xae.25888$AE6.11870@tornado.texas.rr.com...

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

How come the full cost of a programmer and the micro's entire
learning
curve gets factored in every time a micro is mentioned as a
solution?
It's a one time cost, just like the rest of anyones test equipment
or
education. I spent less than $75.00 on my programming hardware and
the
dev tools were free from Microchip. My scope cost me more than $400
fifteen years ago and it was used then. Nobody worries about the
thousands of dollars needed for the rest of the stuff you need to
effectively tinker in electronics, just the $50 for the programmer
like
it's some kind of major show-stopper. IME, debugging time for this
project would be virtually non-existent and the end result would be
more
useful since it would have a much greater dynamic range on the time
constant.


As was mentioned here long ago, and is still true, "Use a PIC" is much
too
generic of a 'solution'. It doesn't teach much about electronic
hardware
and of those that suggest a PIC as a solution, maybe one has followed
through
with schematics AND source code.

I know that I have provided PIC code for more than one person on usenet.
Whenever I suggest using a PIC to someone, you can consider it a given
that I intend to help them with their code and circuitry if they choose
to try it.

Look at the PIC question today, the OP asks why the software he DL
doesn't
see the programmer he built. He links a page but we don't have a clue
if he
etched a PCB of space wired the thing. He has not gotten back with
any
updates. It's typical.

Given the circuit he chose to build, I'm not surprised that it doesn't
work. I would agree that it's "typical" of a good many newbie posts
regardless of whether they're using a PIC. At any rate, his problem has
nothing to do with a PIC chip, yet.

I'm not anti PIC, my burner handles many devices including PIC. I feel
that if it can replace between 6 to 10 ICs or if you need one of their
more advanced features like PIC with USB, then it's okay. I'd have to
admit that their Harvard architecture is odd compared to von Neumann
architecture. I understand the efficiency, it's reminiscent of AOS vs. RPN.

The versions and capabilities are many that one is easily overwhelmed by
the variety. That's one reason why I would like to see a Z-80 running a
TCP/IP stack. It would show that a '70's device still has uses.

 

[Don Kelly]

"Larry Brasfield" <donotspam_larry_brasfield@hotmail.com> wrote in message
news:0mEae.80$QL5.4830@news.uswest.net...

"Don Kelly" <dhky@peeshaw.ca> wrote in message
news:a7Eae.1121148$8l.65597@pd7tw1no...
"Larry Brasfield" <donotspam_larry_brasfield@hotmail.com> wrote in
message
news:U5wae.22$QL5.1414@news.uswest.net...
"CNM" <charles.macleod@gmail.com> wrote in message
news:19123424.0504230929.efc95c8@posting.google.com...
Why does the effciency of my low voltage transformer very much
decrease (to eg 10%) when increasing the frequency to around 40000hz.
Why does this increase in frequency affect the efficiency value so
much?

The most likely reason is that eddy current losses
in the core go up and magnetizing current goes up.
In effect, the shunt inductance of the transformer
goes down as frequency goes up when eddy
currents become signficant. Those currents are
(nearly) in phase with the applied voltage and
represent a loss.
--------
Actually the "magnetising" or inductive component of the current
decreases
because of lower flux density for a given voltage, at higher frequencies
(The inductance won't decrease much if at all) .but the total exciting
current increases due to hysteresis and eddy current loss increases.

I agree with your correction on terminology. I was
incorrectly referring to the shunt current term as
"magnetising current". As for inductance not being
reduced, I have to disagree. If you consider that
eddy current prevents flux from penetrating into
the interior of the laminations, you should be able to
see that the effective area of the core is reduced.
-----------

Eddy currents are due to the flux enclosed in the eddy current path.. True -
they do act to oppose the flux, as do currents in any other transformer
secondary-you see this in an increased primary current to balance.

This effect shows up as a non-polynomial relation
between impedance and frequency, such that the
impedance rises approximately as sqrt(frequency).
If you take the imaginary part of the impedance in
any part of that curve, you will find that inductance
(defined as that component divided by radians/S)
is indeed decreasing with frequency.
--------

Non-linear for sure- however I'll take your word for the rest- I've only
worked with 60Hz transformers. However, just a thought, at higher
frequencies, the effect of the various capacitances comes into play so an
R-L series or parallel model is inadequate.
--
Don Kelly
dhky@peeshaw.ca
remove the urine to answer
-----

This
increased loss current will coupled with skin effects will also lead to
higher I^R loss.

Yes.

You probably have a transformer designed for
line frequency with the lamination thickness set
accordingly. At 40 KHz, that thickness is way
too large.
-----------
Right on- design a 40KHz transformer for 40KHz- don't use a 60Hz
transformer
and expect good operation. It is more than just lamination thickness, it
is
excessive iron.volume as well as capacitive effects. It is a wonder if a
60Hz transformer is not completely useless at 40KHz.

Agreed.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[ZForce]

<RonGrossi382879@yahoo.com> wrote in message

NNTP-Posting-Host: 172.147.84.56

X-Trace: posting.google.com 1114395545 13101 127.0.0.1 (25 Apr 2005 02:19:05
GMT)
X-Complaints-To: groups-abuse@google.com

 

[John Larkin]

On 25 Apr 2005 00:22:19 -0700, williamdob@hotmail.com (william) wrote:

I'm from Belgium ( somewhere in Europe ) ,

I think I've heard of that. It's a small city in Spain, right?

can anyone tell me where I
can buy electronic components on-line in the US ?

Mouser and Digikey are both good. Just .com both names.

thx ( dank u )

Welcome.

John

 

[Anthony Fremont]

"Lord Garth" <LGarth@Tantalus.net> wrote in message news:byYae.498

I wrote:

Given the circuit he chose to build, I'm not surprised that it
doesn't
work. I would agree that it's "typical" of a good many newbie posts
regardless of whether they're using a PIC. At any rate, his problem
has
nothing to do with a PIC chip, yet.


I'm not anti PIC, my burner handles many devices including PIC. I
feel
that if it can replace between 6 to 10 ICs or if you need one of their

6 to 10? That sounds like you may be just a tad bit resistant to using
them. ;-)

more advanced features like PIC with USB, then it's okay. I'd have to
admit that their Harvard architecture is odd compared to von Neumann
architecture. I understand the efficiency, it's reminiscent of AOS
vs. RPN.

Coming from an assembly programming background (on Von Neumann stuff of
course), it was a bit strange to me at first too. PICs, however, are a
godsend for me. They let me build the kind of stuff that I always
wanted to do, without having to dedicate my life to hardware design.
I've also been able to get projects working that I could never have done
the "traditional" way.

The versions and capabilities are many that one is easily overwhelmed
by
the variety. That's one reason why I would like to see a Z-80 running
a
TCP/IP stack. It would show that a '70's device still has uses.

I believe the Rabbit might interest you then. I haven't played with
them, but AIUI they are very much like the Z-80 instruction set and they
come with a TCP/IP stack. They're too expensive for me though.

 

[John Phillips]

On Mon, 25 Apr 2005 15:49:53 +0800, ZForce wrote:

RonGrossi382879@yahoo.com> wrote in message

etc. (snipped)

If you guys wake up and sign up for news.individual.net; you will never
get most of this crap.

 

[John Fields]

On Sat, 23 Apr 2005 10:42:53 -0700, "Larry Brasfield"
<donotspam_larry_brasfield@hotmail.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:qluk61lf2c2m6u277u034u9654lclp41fo@4ax.com...
On Sat, 23 Apr 2005 00:31:26 -0700, "Larry Brasfield"
donotspam_larry_brasfield@hotmail.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:0chi619a9bmorr8pt1pt5qu5ok498dhnv3@4ax.com...
On Fri, 22 Apr 2005 09:42:24 -0700, "Larry Brasfield"
donotspam_larry_brasfield@hotmail.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:560i61tfmof8mhjis826fj5q3dcghb53of@4ax.com...
...
The power needed to drive a buzzer will be many
times larger than what needs to be picked off to
activate another circuit, (many mW versus uW).
---
Depends. The OP's advocating using the signal driving the buzzer to
also drive the LED in an opto, which will be milliwatts VS milliwatts.

I was not addressing use of the optoisolator in that
position. However, if the current taken through the
opto LED is limited to a few 100 uA, such usage
would still be a small fraction of the buzzer power.
As you point out, CTR would be reduced, but no
more than a few uA of output would be needed.

---
That's not the point. As you've already stated, large value pullups
or pull-down resistors may be used in the remote in order to conserve
battery power during switching, and it's precisely that which makes
using an opto in other than a saturated mode problematical. Consider:

+V
|
[100k]
|
+----->Eout
|
O |
|<-
O |
|
GND

In this case, if the load on Eout is insignificant, (CMOS, say) Eout
will be either +V or, assumong GND is at 0V, 0V.

However, in this case:

+V
|
[100k]
|
+----->Eout
|
C A
B <--[LED]
E K
|
GND

Eout will depend on the collector-to-emitter resistance of the
transistor, and if it isn't driven low enough (if the current through
the LED isn't high enough) Eout may not cross the switching threshold
of the driven device.

I've seen commercial uses of photo-transistors
used as switches with 1M pullups. The transistors
themselves do fine at such levels, suffering only
slight beta reduction. Saturation resistance is
very nearly inversely proportional to excess
base current (or the equivalent photocurrent
for a phototransistor), so I see no reason to
expect the problem you allude to here.

---
Without adequate drive the phototransistor will never go into
saturation, so whether the output of the opto can pull the driven load
down (or up) far enough to cross the switching threshold becomes the
problem.
---

As for using the phototransistor in a mode
other than saturated (or nearly off), I have
not suggested that. It might be useful, when
the receiver can deal with a non-switching
input, but that is not the case for the position
I suggested the opto for.

---
I know you haven't suggested that, but it may well be the position the
opto finds itself in if there's not enough photocurrent to drive its
output into saturation. That is, operating linearly, its
collector-to-emitter resistance may be too high to cause the driven
device's switching threshold to be exceeded.
---

The problem can also be exacerbated by the use of cheap conductive
rubber switches which require a substantially lower value pullup.

I thought pullup values would go up in that case,
at least when expressed in Ohms. What makes
you say they would go lower?

---
Yes, you're right. I got it backwards.
---

Additionally, if the remote used pull-down resistors, the opto's
transistor would be operating as a follower which, with only a 3V
supply available in the remote, would complicate matters even more.

The output transistor can be, and often is, used as a two
terminal switch. Even if a base-emitter resistor is added
to control switching speed or leakage, (not needed here),
it can be used that way. Whether it pulls high or low is
not a complication and no follower need be created.

---
That's not the point. If the driven device uses pull-downs and
expects its input to be driven high, then the opto's output (the
emitter) becomes a follower, of necessity.

You might be right though, if the LED drive current is high enough,
but with the microamp drive levels you're proposing, I don't think so.

Run this:

Version 4
SHEET 1 880 680
WIRE -192 208 -192 176
WIRE -192 400 -192 288
WIRE -112 176 -192 176
WIRE -16 400 -16 272
WIRE 32 176 -32 176
WIRE 32 272 -16 272
WIRE 288 240 224 240
WIRE 288 272 288 240
WIRE 288 400 288 352
WIRE 384 176 224 176
WIRE 384 192 384 176
WIRE 384 400 384 272
FLAG 384 400 0
FLAG 288 400 0
FLAG -192 400 0
FLAG -16 400 0
SYMBOL Optos\\4N25A 128 240 R0
SYMATTR InstName U1
SYMBOL voltage 384 176 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 3
SYMBOL res 272 256 R0
SYMATTR InstName R1
SYMATTR Value 100k
SYMBOL voltage -192 192 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 4.5
SYMBOL res -16 160 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R2
SYMATTR Value 100k
TEXT -226 506 Left 0 !.tran 0 .1 0

All of these problems go away with the mechanical contacts of a reed
relay.

Most or all of them go away on their own.

---
I disagree. Doing it your way requires knowing the values of the
pullups and/or pull-down resistors, the contact resistance of the
switch(es), the switching thresholds of the driven device, the drive
level and voltage available from the buzzer to drive the OPTO LED (if
that's how you were planning to do it) and...

My way only requires me to know what the drive voltage to the buzzer
is, or if there's an ALARM ON signal available, what its voltage is.
---

I agree that the reed relay is simpler to apply. For that
reason alone, it may well be most suitable for the OP's
project. My suggestion about an optoisolator in its
place is more like a feasable alternative than any kind
of compelling improvement. Reed relays are fragile
and, if their leads are not carefully heat-sunk during
soldering, they can fail quickly or slowly as a result.
---
Yeah, right! I can just see millions of through-hole reed relays
going through wave-solder machines with little heat sinks attached to
their leads, LOL. Worse yet, millions of surface-mount units going
through soldering ovens with no heat sinks attached...

Ok, that's funny. I was thinking of the bare reed
switches which, due to their glass envelope, are
fragile. Obviously, they are not so fragile when
packaged.

That, together with a dislike of moving parts, made
me think it might be an attractive alternative.

I guess that's not so funny.

---
Take a look at the contact life specs of any reed relay hot switching
microamps and you'll probably get a grin on your chops when you
consider how many centuries worth of garage openings and closings that
comes out to!^)

--
John Fields
Professional Circuit Designer

 

[Lord Garth]

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:v62be.25967$AE6.3244@tornado.texas.rr.com...

"Lord Garth" <LGarth@Tantalus.net> wrote in message news:byYae.498
I wrote:

Given the circuit he chose to build, I'm not surprised that it
doesn't
work. I would agree that it's "typical" of a good many newbie posts
regardless of whether they're using a PIC. At any rate, his problem
has
nothing to do with a PIC chip, yet.


I'm not anti PIC, my burner handles many devices including PIC. I
feel
that if it can replace between 6 to 10 ICs or if you need one of their

6 to 10? That sounds like you may be just a tad bit resistant to using
them. ;-)

more advanced features like PIC with USB, then it's okay. I'd have to
admit that their Harvard architecture is odd compared to von Neumann
architecture. I understand the efficiency, it's reminiscent of AOS
vs. RPN.

Coming from an assembly programming background (on Von Neumann stuff of
course), it was a bit strange to me at first too. PICs, however, are a
godsend for me. They let me build the kind of stuff that I always
wanted to do, without having to dedicate my life to hardware design.
I've also been able to get projects working that I could never have done
the "traditional" way.

The versions and capabilities are many that one is easily overwhelmed
by
the variety. That's one reason why I would like to see a Z-80 running
a
TCP/IP stack. It would show that a '70's device still has uses.

I believe the Rabbit might interest you then. I haven't played with
them, but AIUI they are very much like the Z-80 instruction set and they
come with a TCP/IP stack. They're too expensive for me though.

I thought the Rabbit was too expensive as well. I have a similar product
I bought from Sparkofun, it was about $60. Under the RJ-45 is a 20MHz
processor. It outputs in parallel but I've not yet taken the time to work
with
it.

 

[Larry Brasfield]

"mjohnson" <crvmp3@hotmail.com> wrote in message
news:1114433079.129715.277360@f14g2000cwb.googlegroups.com...

The alarm clock is powered by two AAA batteries and has a piezo buzzer
so I don't think there's any AC involved.

The piezo device requires AC to do anything
above DC. The sound you hear from it is at
the same frequency applied to the buzzer.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Terry Pinnell]

"mjohnson" <crvmp3@hotmail.com> wrote:

The alarm clock is powered by two AAA batteries and has a piezo buzzer
so I don't think there's any AC involved.

That doesn't necessarily follow. Piezo buzzers come in two flavours:

1. Basic component, requiring connection to an external oscillator
(which, of course, delivers AC).

2. With built-in oscillator, requiring DC.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Larry Brasfield]

"Terry Pinnell" <terrypinDELETE@THESEdial.pipex.com> wrote in message
news:2i1q61lhm647heaq25d0v05c45mmle01vd@4ax.com...

"mjohnson" <crvmp3@hotmail.com> wrote:

The alarm clock is powered by two AAA batteries and has a piezo buzzer
so I don't think there's any AC involved.

That doesn't necessarily follow. Piezo buzzers come in two flavours:

1. Basic component, requiring connection to an external oscillator
(which, of course, delivers AC).

2. With built-in oscillator, requiring DC.

Of course, AC is involved then, too.

Mr. Johnson has already mentioned observing 395 mV on the
buzzer when it is sounding. That is not likely to be enough to
run the latter kind of buzzer, so I conclude that his buzzer is
being fed with narrow pulses at whatever voltage the clock's
logic device is powered by.

It is also apparent that the repeated advice he has been given
to measure the AC signal on the buzzer has not been taken.
That ought to reduce interest in this thread, I would think.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Larry Brasfield]

"mjohnson" <crvmp3@hotmail.com> wrote in message
news:1114448695.577717.123340@l41g2000cwc.googlegroups.com...

I guess I'm not sure how to measure the AC then. My multimeter has an
ACV seeting for 200 and 750. I might not understand how to use the
meter. Is that what what I use to measure the VC and do I measure it
across at the two leads attached to the buzzer?

If that is 200 and 750 VAC, you'll have to observe
carefully to see the few volts likely across that buzzer.
It may not go that low if it is a moving needle type.

I suggest that you put a small diode in series with your
meter, use the same DC setting you got the 395 mV
with, and measure in both directions across the buzzer.
You will probably see several volts when it sounds.
That will represent approximately the peak voltage
applied, minus a small diode drop (400 - 500 mV).

Sorry for my ignorance...

No need for that. Please understand that my earlier
comment was a little frustration showing due to an
excess of speculation when what is really needed is
some real data.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[John Fields]

On Mon, 25 Apr 2005 00:43:35 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message

snipped a bunch more side-stepping and invective/ad-hominem crap

---
Translation: "The sonofabitch nailed me, so I'll just shout one more
insult and pretend he didn't. And now for something completely
different..."
---

---
HC4066, about 50 cents, cap about a dime, resistors about a nickle,
diodes about a nickle so, for a one off, that's about $0.70.

Didn't you have a pot in your design?

---
Yeah, but it was a nicety. For the cost-conscious, and if the period
isn't all that critical, 510k +/- 5% will be just fine.
---

PCB, transistor, relay is a wash for either system.

Probably wouldn't need a transistor to drive the relay as long as
5V@25mA will do it. Why not a nice SSR instead?

---
Oh, I don't know... Maybe because that's not what the OP of the thread
in sed you referenced asked for?
---

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

How come the full cost of a programmer and the micro's entire learning
curve gets factored in every time a micro is mentioned as a solution?

---
Because if you haven't bought/built one and you haven't been through
the process, then you'll have to buy/build one and go through the
process if you want to play.
---

It's a one time cost, just like the rest of anyones test equipment or
education.

---
Yes, of course, but it's a one-time cost and an ongoing effort which
will will be unwarranted if the goal at hand is to build a one-off
widget with a total cost of, say, $10 or less.
---

I spent less than $75.00 on my programming hardware and the
dev tools were free from Microchip. My scope cost me more than $400
fifteen years ago and it was used then. Nobody worries about the
thousands of dollars needed for the rest of the stuff you need to
effectively tinker in electronics, just the $50 for the programmer like
it's some kind of major show-stopper.

---
The keyword there is 'tinker'. If that's _your_ bent, then fine.
Spend away. Understand however, that that's not _everyone's_ cup of
tea and that some folks only want a simple, inexpensive, easily
realizable solution for a problem peculiar to them. Asking them to
spend _anything_ on hardware which is going to gather dust after the
project is finished is, at best, stupid. As is asking them to spend
time learning how to use it, and to acquire the software skills
necessary to bring the "project" to completion.
---

IME, debugging time for this
project would be virtually non-existent and the end result would be more
useful since it would have a much greater dynamic range on the time
constant.

---
If you think the OP was wrong in asking for what he wanted, then why
don't you get your ass over to sed and tell him about it instead of
sitting here playing self - aggrandising games and kvetching about
every goddam thing under the sun?

Hint: He doesn't _want_ to be able to change the timing, he just
wants something that'll give him a contact closure, repeatedly, every
hour or so.
---

You figure it out.

Your cost may be a little less assuming a PIC 12Fxxx (~1.20 single qty),
but a 4 bit micro would change that.

---
YAFI, LOL! Suggest away, and don't forget to include the cost of the
programmer and the dev tools, and the time required to learn how to
use them and to learn the instruction set.
---

Outside of the minor cost
difference, I still feel that the micro offers far more potential for a
better end result.

---
"Minor cost difference"? You're either trying to sneak some shit in
there or you can't do, or haven't done, the arithmetic, so I'll do it
for you: Since the transistor, the base resistor, the clamp diode,
the relay and the PCB are a wash, what's left is $1.20 for your
suggested PIC way VS about $0.63 for my way.

That comes to:


$1.20
-$0.63
------
$0.57

which is about 1/2 as expensive as your way. "Minor cost difference"?
I think not.


Hmmm... Where did I read this:

"BTW, I feel that a microcontroller would be a simpler, cheaper, more
reliable (iow better) solution to the problem of resetting the network
appliances on a regular basis. What do you think?"

1. Cheaper? I've just proven that it's not cheaper in onesies, and I
doubt that with that huge cost differential it could be made cheaper
in volume.

2. Simpler? Since the ľC way would require a large investment in time
in order to climb the learning curve, that can hardly be considered a
simpler solution for a one-off.

3. More reliable? I don't have a good handle on the reliability of
either way, so if you have some numbers to back up your position, post
them.

4. What do I think? I think you're full of shit.

--
John Fields
Professional Circuit Designer

 

[John Fields]

On Mon, 25 Apr 2005 02:07:01 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

Given the circuit he chose to build, I'm not surprised that it doesn't
work. I would agree that it's "typical" of a good many newbie posts
regardless of whether they're using a PIC. At any rate, his problem has
nothing to do with a PIC chip, yet.

---
To whom and to what are you referring, specifically?

--
John Fields
Professional Circuit Designer

 

[Bob Eldred]

"CNM" <charles.macleod@gmail.com> wrote in message
news:19123424.0504230929.efc95c8@posting.google.com...

Why does the effciency of my low voltage transformer very much
decrease (to eg 10%) when increasing the frequency to around 40000hz.
Why does this increase in frequency affect the efficiency value so
much?

Core loss is a part of it and core loss goes up with frequency, but flux
density goes down with increasing frequency which helps to ameliorate core
loss. Whatever the core losses are at a given frequency, they would be much
worse if the flux density were maintained at its low frequency value.

Another important loss is driving of the winding capacitance by the
resistance of the windings and by the impedance of the leakage inductance.
This can be a very important loss factor because the AC resistance of the
copper (not impedance) goes up frequency because of skin effect and may
become excessive at 40KHz. The capacitance was most likely ignored in a line
frequency transformer design but can be significant in a 40KHz transformer.
Furthermore higher voltage windings often have higher capacitances and
smaller wire with higher resistance exacerbating the loss effects.

Leakage inductance is the inductance that does not link the primary to the
secondary and therefore no transformer coupling occurs across it. It's just
a series impedance in the way of transferring power across the transformer.
It drives the winding capacitances as mentioned but also is in series with
the load reducing the transfer. Like all inductances, it's impedance
increases with frequency.
Bob

 

[Andrew Holme]

Maddy wrote:

I have the following eqpt
a.Gyro with RS232 or RS422 output (NMEA word $HEHDT ...)
b.Log with RS232 output (NMEA word $GPRMC ...)
c.Standard GPS NMEA output
I want to give these to a single computer with only two serial ports.
I want to combine all these signals and feed them to the computer as a
single input.
Thanks
ps I live in India where nautical electronic hardware is hardly
available. So would prefer a software or circuit diagram which can be
made.

Will they be transmitting data simultaneously?

Do you need bi-directional links i.e. does the computer need to send data /
commands to them?

 

[Anthony Fremont]

"John Fields" <jfields@austininstruments.com> wrote in message

---
Oh, so now you're an authority on the OP?

Only so far as what he posted. I thought he made his skill level fairly
clear.

Whether it was obvious to him or not wouldn't have made a particle of
difference as long as he used a 2N4401, as was shown on the schematic.

That's completely beside the point. Just like the fact that it wouldn't
have worked anyway.

What I think is interesting is that for all your whining about a typo
you had a chance to catch a much more serious _technical_ error, yet
you didn't.

And you think that is something to brag about? LMAO I'm not the one
touting myself as a "professional circuit designer". I'm in it for the
hobby and I've never pretended any different. Perhaps you should have
told the OP that your circuit was untested and unsimulated, because even
I made the mistake of figuring that you actually posted stuff that you
knew would work. I will certainly view your schematics from the proper
perspective from now on.

I didn't feel the need to jump in and make a scene though.

---
You say that now, but earlier you felt that:

"Hey Fields, are you ever going to acknowledge/correct your mistake in
S.E.D about max collector current on the 2N4401?
sheez...."

was better than, say, "BTW, John, you stated in sed that the maximum
collector current for a 2N4401 is 0.6mA. I believe that should be
0.6A." ?

First off the sheez part wasn't addressed to you. You might have
deduced that from the punctuation. Secondly I was being sarcastic, you
should have been able to tell that from the entire context of my post.
At any rate, you are the one setting the precident around here of
jumping down someones throat when you don't like the accuracy of their
posts. Or did you already forget about the photocell and resistor
fiasco in your unending love/hate relationship with Larry? BTW, I don't
think my comment was all that bad, certainly not an FU or anything like
that. I noticed that Mike pointed out your error and you didn't
respond. I thought you might like to know about it. It certainly
woke you up didn't it. :-D

At any rate, the sole reason that I even mentioned you was because you
had already made your attempt at setting me up. Given your typical
behavior lately, I knew what was coming next. I figured my way of
pointing out your mistake was just beating you to the punch. Obviously
I was correct, since you are now so pissed over it.

I certainly didn't cuss you out over it though.

So, on top of everything else, you're either a liar or you have
selective memory lapse problems.

Where did I lie?

I figured you'd catch it or someone else would.

---
Someone else did. Non-confrontationally, BTW

That was his choice. Like you, I reserve the right to respond when and
how I want.

No biggy.

---
One would think...
---

Certainly not
like the sacrilege of misappropriating the word "current" in S.E.B, I
see.

---
It wasn't the word 'current', it was the phrase 'current hogging'.

And?

article. Big fucking deal.

As a matter of fact, it is a BFD now. You wrongly cussed me out,
now
you should apologize. Or do you think you are above that?

---
What I think is that you're trying to mitigate your error by
saying,
"See, everybody makes the same kinds of mistakes I do.", and
there's
no reason for me to apologize to you for flaming you about that.

I don't want an apology for pointing out my mistakes, I want one for
cussing me out after I pointed out your mistake.

---
Had you chosen to point it out in a civil manner I would have
acknowledged in kind but, since you chose not to, fuck you.
And you'll get no apology. Don't like it, sue me.

No need to sue, you are doing enough damage to your business and
reputation all by yourself.

I admit my mistake yet again, when will it be enough for you?

---
Your first admission was sufficient for me, but you seem to feel a
need to keep admitting it, ad nauseam, so the question really should
be: When will it be enough for _you_?

You accused me of weaving and bobbing, so I figured that I hadn't been
plain enough for you.

You, on the other hand, are bobbing and weaving and ducking
around
saying that what you meant by current hogging (a commonly
accepted
technical term) was "power hogging", or some such other nonsense
and
trying to excuse your error by saying that I'm in the same boat
that
you're in, LOL.

I admitted that current was the wrong word, WTF do you want me to
do?

---
I dont care _what_ you do.

I guess that's only as long as I don't say "current" when I really
mean
"power".

---
You misunderstand me. "I don't care what you do" means precisely
that. Make mistakes, don't make mistakes, it makes no difference to

me. Choosing to comment one way or the other is my prerogative and is
not based on caring about what you do, it's based on fixing the error.

Then, why did my comment upset you? I was only prompting you to fix
your error. I didn't call you any names, or use an cuss words so why
did you find it so upsetting?

Do you really think that I don't know the difference between
current
and
power, or that the current thru all components in a series circuit
is
the same?

---
You do now...

I think I knew it 25 or 30 years ago.

---
Yes, well, if you don't use it you lose it.

I think I can still tell the difference between current, power and
energy. I think you know that too or you'd be filling your posts with
links to all my past errors.

I really didn't expect the pedant police to jump all over it.

---
Shit happens...
---

Next time I'll be more careful.

---
Good.

whatever

---
Weak.

Not half as weak as someone that feels a need to dominate a basics
newsgroup just cuz they're an expert in the field.

The simple fact remains that one LED WILL DISIPATE MORE POWER THAN
THE
OTHER DUE TO DIFFERING Vf's. RIGHT???

---
Right.
---

At least we can agree on something.

THE END RESULT IS EXACTLY THE
SAME AS IF ONE DEVICE HOGGED MORE CURRENT, RIGHT???

---
Wrong. That's the same as saying that getting from point A to point
B
via a road that doesn't exist is the same as getting from point A
to
point B via road that does exist.

Your falacious analogy aside, the end result is a smoked part. The
same
as when you put too much current thru it. I defy you to tell the
difference in a post-mortem exam.

---
You just can't let it go, can you?

Fact is, in a post-mortem exam the second LED would be very closely
examined and could yield some clues as to what happened to the toasted
LED. For instance, if the LED failed open and the second LED's Vf,
If, and light output were in spec once it was fired up again, then the
failure of the first LED could have been a wire bond failure or who
knows what else at a current substantially _below_ Ifmax.

Just for grins, why don't you work out the power dissipation of each
of two LEDs in series, one with Vfmin and the other with Vfmax with
nominal If going through both of them and see if that causes the high
Vf LED to dissipate more than its maximum rated power?
---

I have admitted my
error numerous times now. Now, what is your problem?

---
I have no problem.
---

Other than your inability to apologize for cussing someone out and
calling them names.

---
On the contrary, I'm perfectly capable of apologizing when it's
warranted.
---


I'm not saying that you're in the same boat as me, I am saying
that
you
make mistakes too. What I'd like to know is:

Would you rather have someone point it out nicely, or would you
rather
them try to trip you up so that you can dig yourself in deeper?
Let
me
know so that I may properly appease you in the future.

---
Neither my appeasement nor your sarcasm is necessary. Besides, I
don't know why you're so offended by what you thought was a trick
question since, trick question or not, it certainly woke you up
quickly enough!
---

Too bad you didn't "wake up" to your "trypo" until after cussing me
out.

---
Again, had you chosen to point it out in a civil manner I would have
acknowledged in kind but, since you chose not to, fuck you.

Perhaps if you acted a little more civil around here, I would be
inclined to be nicer to you. As it stands, you certainly are
demonstrating that you deserve far less courtesy than I've shown you.

BTW, I feel that a microcontroller would be a simpler, cheaper,
more
reliable (iow better) solution to the problem of resetting the
network
appliances on a regular basis. What do you think?

---
Is that a trick question?

no

---
HC4066, about 50 cents, cap about a dime, resistors about a nickle,
diodes about a nickle so, for a one off, that's about $0.70.

PCB, transistor, relay is a wash for either system.

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

You figure it out.

--
John Fields
Professional Circuit Designer

 

[Anthony Fremont]

"John Fields" <jfields@austininstruments.com> wrote in message
news:fe8q61pdi7787n4c5c2sqvsqhj77nb9vrf@4ax.com...

On Mon, 25 Apr 2005 00:43:35 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message

snipped a bunch more side-stepping and invective/ad-hominem crap

---
Translation: "The sonofabitch nailed me, so I'll just shout one more
insult and pretend he didn't. And now for something completely
different..."

However you wish to see it John, though I didn't use any cuss words.

---
HC4066, about 50 cents, cap about a dime, resistors about a nickle,
diodes about a nickle so, for a one off, that's about $0.70.

Didn't you have a pot in your design?

---
Yeah, but it was a nicety. For the cost-conscious, and if the period
isn't all that critical, 510k +/- 5% will be just fine.

I'd go with jumpers on a micro. They're cheap and highly configurable.

PCB, transistor, relay is a wash for either system.

Probably wouldn't need a transistor to drive the relay as long as
5V@25mA will do it. Why not a nice SSR instead?

---
Oh, I don't know... Maybe because that's not what the OP of the thread
in sed you referenced asked for?

An SSR doesn't qualify as a relay?

A one off for a micro is gonna cost you the micro, a programmer, a
learning curve and programming and debugging time.

How come the full cost of a programmer and the micro's entire
learning
curve gets factored in every time a micro is mentioned as a solution?

---
Because if you haven't bought/built one and you haven't been through
the process, then you'll have to buy/build one and go through the
process if you want to play.
---

The same goes for test equipment, soldering stuff etc.... It's just one
more tool that you need, nothing more. A good PIC programmer is less
than $100. Compared to the $150 I spent on my audio frequency generator
that I almost never use, it's a great investment.

It's a one time cost, just like the rest of anyones test equipment or
education.

---
Yes, of course, but it's a one-time cost and an ongoing effort which
will will be unwarranted if the goal at hand is to build a one-off
widget with a total cost of, say, $10 or less.

But it would be worth buying a DMM, a soldering iron, solder, etching
stuff etc.....?

I spent less than $75.00 on my programming hardware and the
dev tools were free from Microchip. My scope cost me more than $400
fifteen years ago and it was used then. Nobody worries about the
thousands of dollars needed for the rest of the stuff you need to
effectively tinker in electronics, just the $50 for the programmer
like
it's some kind of major show-stopper.

---
The keyword there is 'tinker'. If that's _your_ bent, then fine.
Spend away. Understand however, that that's not _everyone's_ cup of
tea and that some folks only want a simple, inexpensive, easily
realizable solution for a problem peculiar to them. Asking them to

Well, I guess that I see PIC chips like you see 74xx's

spend _anything_ on hardware which is going to gather dust after the
project is finished is, at best, stupid. As is asking them to spend
time learning how to use it, and to acquire the software skills
necessary to bring the "project" to completion.

Burning yet another straw man, you really are a fire bug. I don't
recall asking anyone to spend money on equipement to be used once. As I
"self agrandised" before, if I was adamently suggesting a PIC to
someone, I'd be offering some help to go with it. You can make of that
what you wish.

IME, debugging time for this
project would be virtually non-existent and the end result would be
more
useful since it would have a much greater dynamic range on the time
constant.

---
If you think the OP was wrong in asking for what he wanted, then why
don't you get your ass over to sed and tell him about it instead of
sitting here playing self - aggrandising games and kvetching about
every goddam thing under the sun?

Er um, because I don't want to. You really ought to stop trying to
control things around here. Ordering people around on usenet is not
likely to win you many friends.

Hint: He doesn't _want_ to be able to change the timing, he just
wants something that'll give him a contact closure, repeatedly, every
hour or so.
---

You figure it out.

Your cost may be a little less assuming a PIC 12Fxxx (~1.20 single
qty),
but a 4 bit micro would change that.

---
YAFI, LOL! Suggest away, and don't forget to include the cost of the
programmer and the dev tools, and the time required to learn how to
use them and to learn the instruction set.

Programmers and dev tools don't count. We've already covered this.
They are in the same category as all other dev tools and electronics
equipment you own.

Outside of the minor cost
difference, I still feel that the micro offers far more potential for
a
better end result.

---
"Minor cost difference"? You're either trying to sneak some shit in
there or you can't do, or haven't done, the arithmetic, so I'll do it
for you: Since the transistor, the base resistor, the clamp diode,
the relay and the PCB are a wash, what's left is $1.20 for your
suggested PIC way VS about $0.63 for my way.

That comes to:


$1.20
-$0.63
------
$0.57

which is about 1/2 as expensive as your way. "Minor cost difference"?
I think not.

It's certainly not half as expensive when you factor in a board and the
rest of the common parts. The difference quickly shrinks to ~10% or
less, now doesn't it? It's really not very attractive watching an
engineer play games with numbers like he's doing Enron's books.

Hmmm... Where did I read this:

"BTW, I feel that a microcontroller would be a simpler, cheaper, more
reliable (iow better) solution to the problem of resetting the network
appliances on a regular basis. What do you think?"

1. Cheaper? I've just proven that it's not cheaper in onesies, and I
doubt that with that huge cost differential it could be made cheaper
in volume.

Admittedly for one off, it's pretty hard to be cheaper using an 8-bit
micro. A 4-bit proc would do the job, and it would be cheaper. BTW,
your quoted prices were a bit low as shown on Digikey, so things aren't
as bad as you wish to make it seem. Of course your price was 70 cents
yesterday and now it's only 63 cents, so why am I not surprised?
According to Digikey, the fairchild 4060 is 77 cents in single qty, the
ST part is 55 cents each.

2. Simpler? Since the ľC way would require a large investment in time
in order to climb the learning curve, that can hardly be considered a
simpler solution for a one-off.

What about the electronics learing curve? It's only about 1000 times
larger, be for real. That's the same old tired mantra formerly sung by
"professional tube circuit designers" when whining about having to learn
yucky old transistor theory.

3. More reliable? I don't have a good handle on the reliability of
either way, so if you have some numbers to back up your position, post
them.

4. What do I think? I think you're full of shit.