Re: 12 LED resistance circuit help

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

>
>"John Fields" <jfields@xxxxxxxxxxxxxxxxxxxxx> wrote in message
>news:4run61185tuf10b6o6rvuo10bhh6fqf7ia@xxxxxxxxxx
>> On Sun, 24 Apr 2005 18:12:30 GMT, "Anthony Fremont"
>> <spam@xxxxxxxxxxxx> wrote:
>>
>> >
>> >"John Fields" <jfields@xxxxxxxxxxxxxxxxxxxxx> 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 60µA, 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 data*** 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, *** 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.
>>
>> ---
>> *** 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, *** 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
.