Chip with simple program for Toy

[Anthony Fremont]

"dB" <dmb06851@yahoo.com> wrote in message
news:1757808.0504232017.529c5041@posting.google.com...

John Bokma <postmaster@castleamber.com> wrote

and due to the resistor, one LED can only have a higher voltage
if another LED has less.

"Due to the resistor"? What a strange thing to say.

The resistor limits the current, it has no direct effect on the
voltage developed across each l.e.d. The actual value across each

Vf _is_ dependant upon current. At extremely low currents, Vf will be
significantly lower than the nominal value. As current increases, so
will Vf. The curve is steep, but it is not vertical.

l.e.d. varies from device to device at any current. The data sheets
give a "typical" Vf and sometimes a max figure.

If it is a detailed datasheet it will also specify a test condition
clause giving the current associated with the stated Vf. Like this one
for example:
http://www.epitex.com/Catalog_PDF/08_Point_source_LED/L590CE-34F.PDF
The datasheet sometimes specifies a minimum Vf as well. The max Vf can
be as much as double the min Vf. Like Ripley says, believe it or not.
;-)

 

[Anthony Fremont]

"dB" <dmb06851@yahoo.com> wrote in message
news:1757808.0504231310.77609fb9@posting.google.com...

"Anthony Fremont" <spam@anywhere.com> wrote
Since there are two LEDs in series, one may hog more current than
the other


In a series circuit the current is equal through each component.

Yeah, I know. I messed up, I should have said power, so sue me. ;-)

 

[Jamie]

aman wrote:

I have seen in some analog circuits that if we need a 2.5 V supply
there is way to do it that generate a 5V square pulse with duty cycle
1/2 and pass it through a low pass filter to get a DC 2.5V.

I was thinking of another way of generating 2.5V. Use a voltage divider
and then use an opamp buffer.

Which of the above 2 ways is a recommended way of generating 2.5V DC?

normally a circuit like that is used to generate - voltages from a

+ source like in battery operated equipment etc. .
if you already have a + supply and that is all you need, then using
a simple Voltage regulator from the main source should work.
something like a resistor and zener combo or a fixed reg. etc..

 

[Jamie]

John Popelish wrote:

aman wrote:

I just need 2.5V to be at one of the inputs of the opamp. I will be
using the virtual ground property of opamp getting 2.5V at the other
input of the opamp also. I dont need practically any current to be
drawn by the load because after opamp theren will be only a schmitt
trigger(comparator). So that you know this is part of an water overflow
detector. Still you think the regulator or voltage divider are good
ideas for this.


A simple two resistor divider may be all you need.
If only an opamp input is connected to it (no current load except the
opamp bias current) a pair of 100k resistors may be stiff enough.
thats what she said!

 

[Andrew Holme]

Maddy wrote:

I have a system giving an RS 232 output with logical 0 at +15V and
logical 1 at -15V. Is this signal safe to connect to the serial port
of a computer? If not how do I use this for a computer input? and to
which pin should I connect it. Please Help! Urgent! Thanks

Your PC serial port is designed to accept voltages which meet the RS232
specification.

Try Googling for keywords like:

RS232 min max voltage
RS232 pc serial port pinout

You will find hundreds of sites answering your question.

 

[Lord Garth]

"Andrew Holme" <andrew@nospam.com> wrote in message
news:d4gd4m$j45$1$8300dec7@news.demon.co.uk...

Maddy wrote:
I have a system giving an RS 232 output with logical 0 at +15V and
logical 1 at -15V. Is this signal safe to connect to the serial port
of a computer? If not how do I use this for a computer input? and to
which pin should I connect it. Please Help! Urgent! Thanks

Your PC serial port is designed to accept voltages which meet the RS232
specification.

Try Googling for keywords like:

RS232 min max voltage
RS232 pc serial port pinout

You will find hundreds of sites answering your question.

The short answer is yes, it is safe.

The longer answer is not to experiment on ports you can't fix like the ports
integrated
into you laptop or motherboard.

 

[Jamie]

cornytheclown@hotmail.com wrote:

Ive seen a lot of industrial controllers such as plcs and they all seem
to use a signal of 4-20 ma in proportion to relay sensor information to
the controller.

My question is .....why 4-20 ma.....why not 1-10 ma or 1-50 ma... what
is the reasoning between using 4-20 milliamps

thanks

4..40 ma is actually the common range for many industrial units, that is

why when you get a little current source hand held, you will noticed
that most of them will at least 40 ma's
the one i use will do up to 100 ma, but i have never used it that high.
its a nice tool if you need to calibrate a device to work with in a
range of (ma) window far from the actual controller that drives it.
steam/plumber fitters and the like must make sure that the valves
for example actuate properly for the described range.
--
currents sourcing is nice because you can assure that you are getting
above some levels of current ambient current caused by adjacent wires in
raceways and the like but, this only applies to small levels of course.
current loops are also used in close loops type of communication
devices so that all devices on the line can monitor current activity so
that it can talk to the other units on the same wire or not collide with
current traffic.
these kind of devices normally need to have one unit as the current
source, the source current device normally tries to maintain the set
current point was devices get added on the line.
most devices use an optical type coupling or a LED or transistor,
depending on the direction of flow. each device creates a lost of
voltage that the current source supplies. at some given point, the
current source will not be able to maintain it as devices are added in
the loop of course, this is where repeaters come into play!
depending on the manf and device, the number of devices can really
get up there, for example RedLion type of serial display of a type i
have in mind usings 20 ma current loop supplied from an 18 volt source,
these units can address up to 100 0..99, but since each device and lose
and average of 0.7 volts in the TX state and 1.7 in the RX state, it
kind of limits the number of devices you can actually have on the loop.

enough of that.
...

 

[John Fields]

On Sun, 24 Apr 2005 09:12:33 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com
wrote in message

Heh. Some advice handed out in the NG is really atrocious, ain't it?

I guess the restatement I made is not good enough. Should I start
another thread and offer a formal apology to the world for making such a
heinous mis-statement about current vs. dissipation?

---
Current VS dissipation isn't where you erred, you stated that
current-hogging was taking place in a series circuit, where currents
are everywhere the same and hogging _can't take place.
---

Maybe I could help
make amends by belittling others, nit-picking posts and posting a bunch
of OT crap?

---
That seems a little extreme. Usually all that's required is an "oops"
or an "aaarrghhh!" or a simple admission of error.
---

Lets see if we can't get on to the road to recovery now. Speaking of
good advice, why are you trying to get a poster to use non-rechargeable
alkaline batteries when he clearly expressed a preference for
rechargeable? Hey Fields, are you ever going to acknowledge/correct
your mistake in S.E.D about max collector current on the 2N4401?
sheez....

---
Fuck you, pinhead. Go to:

http://www.fairchildsemi.com/ds/2N%2F2N4401.pdf

and read the absolute maximum rating for collector current, then
report back with what you find along with a reference to the article,
OK?

--
John Fields
Professional Circuit Designer

 

[Larry Brasfield]

"John Fields" <jfields@austininstruments.com> wrote in message
news:ao8l61ttqshucd4gb8ndt3asj2l74gsq2g@4ax.com...

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.

Agreed.

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.

I think we can noisily agree that using sufficient
current is necessary with the optoisolator and
that it should be more or less saturated when
used to replace a switch.

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.

I think we have merely a terminolgy issue here.
You are willing to call a two terminal circuit a
follower. I use the term for common {emitter,
source, cathode} amplifiers.

However, maybe you think the underlying facts
impact the operation, and that being a follower
limits the voltage in the pullup configuration more
than in the pulldown configuration. In that case,
I suggest you connect a 1T resistor from the
base of the 4N25A in your simulation to ground
and run it, then observe the base voltage. You
may be surprised to see it more positive than the
other two terminals by about a diode drop.

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.

I've only made one explicit statement about the
LED current, suggesting it might be "limited to
a few 100 uA". More on this in a moment.

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

Interesting. It certainly demonstrates the reduction
of CTR at lower currents. When I reduce the LED
current setting resistor to 36K to get about 100 uA
thru the LED, the output saturates nicely. And with
that 1T resistor, the base goes to 3.53 V.

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've already agreed that the relay solution is easier
to apply. My reason for stating so is exactly the
sort of required knowing you mention. For that
reason, (and the capacitance issue I've posted), I
think your solution is entirely appropriate for the
OP's purpose.

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.
....
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!^)

Ok, that's funny too. I could quibble about centuries
being the proper unit of measurement. (What falls
between millenia and eons?) I never claimed my
dislike of moving parts was rational!

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

 

[Anthony Fremont]

"dB" <dmb06851@yahoo.com> wrote in message
news:1757808.0504240718.1ebdb09b@posting.google.com...

"Anthony Fremont" <spam@anywhere.com> wrote

Vf _is_ dependant upon current.

I neither said nor implied that it wasn't.

I guess I misunderstood you when you said:

"The actual value across each l.e.d. varies from device to device at any
current."

At extremely low currents, Vf will be
significantly lower than the nominal value. As current increases,
so
will Vf. The curve is steep, but it is not vertical.

Yes, the curve is in an article on my site. (I can suck eggs.)

You seem to have misundersood my post which was regarding the
ambiguous sentence "However the current should
stay 20 mA, and due to the resistor, one LED can only have a higher
voltage
if another LED has less."

 

[Anthony Fremont]

"John Fields" <jfields@austininstruments.com> wrote in message
newssen61hv1sbf2646pnvv0a7pg7uhdj6i35@4ax.com...

On Sun, 24 Apr 2005 09:12:33 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


"Watson A.Name - "Watt Sun, the Dark Remover""
NOSPAM@dslextreme.com
wrote in message

Heh. Some advice handed out in the NG is really atrocious, ain't
it?

I guess the restatement I made is not good enough. Should I start
another thread and offer a formal apology to the world for making
such a
heinous mis-statement about current vs. dissipation?

---
Current VS dissipation isn't where you erred, you stated that
current-hogging was taking place in a series circuit, where currents
are everywhere the same and hogging _can't take place.
---

I know, that's why I said, "that I should have said power instead of
current". I was going to say "hogging the juice" but changed it to the
incorrect word of current (instead of power) and I really wish that I
had stuck with juice.

Maybe I could help
make amends by belittling others, nit-picking posts and posting a
bunch
of OT crap?

---
That seems a little extreme. Usually all that's required is an "oops"
or an "aaarrghhh!" or a simple admission of error.

I would have, if you'd have just pointed out my mistake like dB did.
Instead, for some twisted reason, you try to set me up with a little
trick question.

---

Lets see if we can't get on to the road to recovery now. Speaking of
good advice, why are you trying to get a poster to use
non-rechargeable
alkaline batteries when he clearly expressed a preference for
rechargeable? Hey Fields, are you ever going to acknowledge/correct
your mistake in S.E.D about max collector current on the 2N4401?
sheez....

---
Fuck you, pinhead. Go to:

http://www.fairchildsemi.com/ds/2N%2F2N4401.pdf

and read the absolute maximum rating for collector current, then
report back with what you find along with a reference to the article,
OK?

OK, Mr. "professional circuit designer", I already did that and that's
why I know you made a mistake. You incorrectly stated that the max
current was ".6mA", IOW 600uA. The correct number is 600mA or .6A, but
it is certainly not .6mA. I realize that's only three orders of
magnitude off, so perhaps that's close enough for you, but it's not for
me. Now awaiting your apology (for leaping to conclusions and then
cussing me out) and your admission of error.

I hope this link works:
http://groups-beta.google.com/group/sci.electronics.design/browse_frm/thread/96bd1581c0bf581d/07d336d4a9dce9b2?q=2n4401+author:john+author:fields&rnum=2&hl=en#07d336d4a9dce9b2

Now.......wasn't that allot more productive than just pointing out the
mistake? Not.

 

[John Fields]

On Sun, 24 Apr 2005 16:52:33 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
newssen61hv1sbf2646pnvv0a7pg7uhdj6i35@4ax.com...
On Sun, 24 Apr 2005 09:12:33 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


"Watson A.Name - "Watt Sun, the Dark Remover""
NOSPAM@dslextreme.com
wrote in message

Heh. Some advice handed out in the NG is really atrocious, ain't
it?

I guess the restatement I made is not good enough. Should I start
another thread and offer a formal apology to the world for making
such a
heinous mis-statement about current vs. dissipation?

---
Current VS dissipation isn't where you erred, you stated that
current-hogging was taking place in a series circuit, where currents
are everywhere the same and hogging _can't take place.
---

I know, that's why I said, "that I should have said power instead of
current". I was going to say "hogging the juice" but changed it to the
incorrect word of current (instead of power) and I really wish that I
had stuck with juice.

Maybe I could help
make amends by belittling others, nit-picking posts and posting a
bunch
of OT crap?

---
That seems a little extreme. Usually all that's required is an "oops"
or an "aaarrghhh!" or a simple admission of error.

I would have, if you'd have just pointed out my mistake like dB did.
Instead, for some twisted reason, you try to set me up with a little
trick question.

---

Lets see if we can't get on to the road to recovery now. Speaking of
good advice, why are you trying to get a poster to use
non-rechargeable
alkaline batteries when he clearly expressed a preference for
rechargeable? Hey Fields, are you ever going to acknowledge/correct
your mistake in S.E.D about max collector current on the 2N4401?
sheez....

---
Fuck you, pinhead. Go to:

http://www.fairchildsemi.com/ds/2N%2F2N4401.pdf

and read the absolute maximum rating for collector current, then
report back with what you find along with a reference to the article,
OK?

OK, Mr. "professional circuit designer", I already did that and that's
why I know you made a mistake. You incorrectly stated that the max
current was ".6mA", IOW 600uA. The correct number is 600mA or .6A, but
it is certainly not .6mA. I realize that's only three orders of
magnitude off, so perhaps that's close enough for you, but it's not for
me. Now awaiting your apology (for leaping to conclusions and then
cussing me out) and your admission of error.

I hope this link works:
http://groups-beta.google.com/group/sci.electronics.design/browse_frm/thread/96bd1581c0bf581d/07d336d4a9dce9b2?q=2n4401+author:john+author:fields&rnum=2&hl=en#07d336d4a9dce9b2

Now.......wasn't that allot more productive than just pointing out the
mistake? Not.

---
Sure, I made a trypo, which is clearly evident from the context of the
article. Big fucking deal.

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.

--
John Fields
Professional Circuit Designer

 

[Anthony Fremont]

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

Sure, I made a trypo, which is clearly evident from the context of the

Clearly evident, are you trying to be funny? There is nothing "clearly
evident" about 0.6mA REALLY meaning 600mA.

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?

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?
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? I really didn't expect the pedant police to jump all over it.
Next time I'll be more careful.

The simple fact remains that one LED WILL DISIPATE MORE POWER THAN THE
OTHER DUE TO DIFFERING Vf's. RIGHT??? THE END RESULT IS EXACTLY THE
SAME AS IF ONE DEVICE HOGGED MORE CURRENT, RIGHT??? I have admitted my
error numerous times now. Now, what is your problem?

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.

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?

 

[Lord Garth]

"alismans" <kayleemac@btinternet.com> wrote in message
news:5fb342c0.0504241127.309527f8@posting.google.com...

I am trying to use the programmer from

http://members.aon.at/electronics/pic/picpgm/index.html

I have built the circuit
picpgm_cable according to the diagram. I have used a
74LS04 instead of 74ALS05 because this is what was
available. I then run the software WinPicPgm and on
the status line at the bottom there is a message
"No pic programmer found".
Can you help me?
thanks!!

At a glance I found this:

"A driver which is necessary to access the parallel port under Windows 2k/XP
is included and loaded automatically by the programmer software (no user
interaction necessary). "

It seems as if your driver isn't loading, look for it in your task manager.
Further, is your
parallel port on 0378h or one of the other two standard addresses?

Is your motherboard BIOS set to use the port as ECP ?

 

[Lord Garth]

"alismans" <kayleemac@btinternet.com> wrote in message
news:5fb342c0.0504241127.309527f8@posting.google.com...

I am trying to use the programmer from

http://members.aon.at/electronics/pic/picpgm/index.html

I have built the circuit
picpgm_cable according to the diagram. I have used a
74LS04 instead of 74ALS05 because this is what was
available. I then run the software WinPicPgm and on
the status line at the bottom there is a message
"No pic programmer found".
Can you help me?
thanks!!

It looks like they assume you know to connect 5 volts and ground
to the 74ALS04...did you power the inverter? It works best when
power is present!

 

[John Fields]

On Sun, 24 Apr 2005 18:12:30 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

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

Sure, I made a trypo, which is clearly evident from the context of the

Clearly evident, are you trying to be funny? There is nothing "clearly
evident" about 0.6mA REALLY meaning 600mA.

---
Well, had you noticed that earlier on in the article I referred to
being able to run a relay with a 100mA coil, and had you noticed that
that relay was in series with the collector-to-emitter junction of the
transistor, it should have been obvious that, in the absence of
current-hogging, that 100mA also had to pass through the transistor's
collector-to-emitter junction in order to cause the relay to function.
Also, I don't think there are any commonly available mechanical relays
with will operate with coil currents on the order of 60ľA, so it
should have been more or less obvious that it was a trypo. Especially
when you consider that just removing the mu fixes everything.
---

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.
---

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.
---

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

---
Shit happens...
---

Next time I'll be more careful.

---
Good.
---

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

---
Right.
---

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.
---

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

---
I have no problem.
---

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!
---

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?

--
John Fields
Professional Circuit Designer

 

[John Fields]

On Sun, 24 Apr 2005 15:22:26 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Sun, 24 Apr 2005 18:12:30 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


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

Sure, I made a trypo, which is clearly evident from the context of the

Clearly evident, are you trying to be funny? There is nothing "clearly
evident" about 0.6mA REALLY meaning 600mA.

---
Well, had you noticed that earlier on in the article I referred to
being able to run a relay with a 100mA coil, and had you noticed that
that relay was in series with the collector-to-emitter junction of the
transistor, it should have been obvious that, in the absence of
current-hogging, that 100mA also had to pass through the transistor's
collector-to-emitter junction in order to cause the relay to function.
Also, I don't think there are any commonly available mechanical relays
with will operate with coil currents on the order of 60ľA, so it
^^

Oops... 600

should have been more or less obvious that it was a trypo. Especially
when you consider that just removing the mu fixes everything.
---

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.
---

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.
---

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

---
Shit happens...
---

Next time I'll be more careful.

---
Good.
---

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

---
Right.
---

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.
---

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

---
I have no problem.
---

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!
---

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?

--
John Fields
Professional Circuit Designer

 

[Anthony Fremont]

"John Fields" <jfields@austininstruments.com> wrote in message
news:4run61185tuf10b6o6rvuo10bhh6fqf7ia@4ax.com...

On Sun, 24 Apr 2005 18:12:30 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


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

Sure, I made a trypo, which is clearly evident from the context of
the

Clearly evident, are you trying to be funny? There is nothing
"clearly
evident" about 0.6mA REALLY meaning 600mA.

---
Well, had you noticed that earlier on in the article I referred to
being able to run a relay with a 100mA coil, and had you noticed that
that relay was in series with the collector-to-emitter junction of the
transistor, it should have been obvious that, in the absence of
current-hogging, that 100mA also had to pass through the transistor's
collector-to-emitter junction in order to cause the relay to function.
Also, I don't think there are any commonly available mechanical relays
with will operate with coil currents on the order of 60ľA, so it
should have been more or less obvious that it was a trypo. Especially
when you consider that just removing the mu fixes everything.

It was obvious to me for all the reasons you mention, that's why I went
and looked at the datasheet yesterday to see. However, it might not
have been obvious to the OP (and it likely wasn't) given his post and
his nym. I didn't feel the need to jump in and make a scene though. I
figured you'd catch it or someone else would. No biggy. Certainly not
like the sacrilege of misappropriating the word "current" in S.E.B, I
see.

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. I admit my mistake yet
again, when will it be 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".

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.

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

---
Shit happens...
---

Next time I'll be more careful.

---
Good.

whatever

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.

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.

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.

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

 

[John Fields]

On Sun, 24 Apr 2005 21:03:39 GMT, "Anthony Fremont"
<spam@anywhere.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:4run61185tuf10b6o6rvuo10bhh6fqf7ia@4ax.com...
On Sun, 24 Apr 2005 18:12:30 GMT, "Anthony Fremont"
spam@anywhere.com> wrote:


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

Sure, I made a trypo, which is clearly evident from the context of
the

Clearly evident, are you trying to be funny? There is nothing
"clearly
evident" about 0.6mA REALLY meaning 600mA.

---
Well, had you noticed that earlier on in the article I referred to
being able to run a relay with a 100mA coil, and had you noticed that
that relay was in series with the collector-to-emitter junction of the
transistor, it should have been obvious that, in the absence of
current-hogging, that 100mA also had to pass through the transistor's
collector-to-emitter junction in order to cause the relay to function.
Also, I don't think there are any commonly available mechanical relays
with will operate with coil currents on the order of 60ľA, so it
should have been more or less obvious that it was a trypo. Especially
when you consider that just removing the mu fixes everything.

It was obvious to me for all the reasons you mention, that's why I went
and looked at the datasheet yesterday to see. However, it might not
have been obvious to the OP (and it likely wasn't) given his post and
his nym.

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

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.

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.
---

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." ?

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

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

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

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'.
---

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.
---

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, 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.
---

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

---
Shit happens...
---

Next time I'll be more careful.

---
Good.

whatever

---
Weak.
---

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.
---

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

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

---
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?

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?

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.

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