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Old 13th August 2003, 08:22 AM   #11
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Default Re: I agree with Charlie........

Quote:
Originally posted by Jocko Homo
Add SE's nonsense to the list.
Hey, I don't claim to be perfect like Charles here. And I don't go around like Charles trying to tell people not to post anything unless they "*really* know" what they're talking about.

Quote:
Hey Steve......you might try building something for a change instead of running down everyone else. Especially people who know a lot more than you do.
The running down was already done by Charles in his reply to jcx.

I'm simply pointing out that those who talk about open-loop emitter followers shouldn't be going around impugning others for posting something which may be erroneous and trying to tell them not to post anything unless they *really* know what they're talking about.

As for building something, I did try to build me one of them open-loop emitter followers that Charles recommended only to find out that they don't exist.

se
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Old 13th August 2003, 02:40 PM   #12
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Default Re: Re: I agree with Charlie........

Quote:
Originally posted by Steve Eddy

As for building something, I did try to build me one of them open-loop emitter followers that Charles recommended only to find out that they don't exist.

se
Steve, for a guy with encyclopedic knowledge of everything from Cooper pairs to altered states of conciousness, you sure seem to have a hard time reading. Let me help you out with this one. For an example of an open-loop follower, please refer to the data sheet for the Burr-Brown BUF634:

http://focus.ti.com/lit/ds/symlink/buf634.pdf

The first sentence in the section "Application Information" reads as follows:

"Figure 1 is a simplified circuit diagram of the BUF634 showing its open-loop complementary follower design."

They even give the schematic, so if you *really* want to build an open-loop follower, you could do so. Or you could just buy one from DigiKey.

On the other hand if you wanted a closed-loop follower, please refer to the data sheet for a National LMH6559 for an example:

http://www.national.com/ds/LM/LMH6559.pdf

On the first page you will find the information, "The LMH6559 is a high-speed, closed-loop buffer...configured internally for a loop gain of one."

Now they don't offer a schematic, so if you want to build one of these but are having trouble figuring out how this thing works, just post on this forum and I'm sure that somebody with some knowledge like Jocko or John Curl (Fred unfortunately left in disgust) will be glad to help you out.

But all of this is really silly. In case you haven't realized it, you've "hijacked" this thread. The original poster had a specific question regarding the construction of a specific circuit. None of this is helpful or illuminating to him (or anyone else, for that matter).

For you to drag in one of your old arguments from a thread on a completely different forum (Audio Asylum) is out of line and uncalled for. This argumentative behavior that generates heat and no light is exactly why you have been banned from some forums. It is exactly why new rules have been created on other forums. It is exactly why so many people on this forum wish the moderators would ban you.

If you have something helpful to add to the original poster's question, please do so. Otherwise, I'm sure everyone would appreciate it if you refrained from posting altogether.

Charles Hansen
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Old 13th August 2003, 02:43 PM   #13
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Default Oh, I almost forgot...

That was the last time I will ever reply to one of your posts on the DIY Audio forum. Since all you like to do is argue, making any replies just drags the argument out. Nobody comes to these places to listen to arguments (except apparently you). So go ahead and argue away, all by yourself.

Charles Hansen
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Old 13th August 2003, 02:48 PM   #14
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Default I agree with Charlie......again......

Steve, if I knew as little as you seem to, I wouldn't draw attention to myself.

Arguing with you is about as productive as screaming at the freeloading cat that lives on my patio: it occasionally makes me feel good, but accomplishes nothing.

Jocko
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Old 13th August 2003, 04:06 PM   #15
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Angry Knowledge doesn't count..........

I got an Email from a very knowledgable
poster saying he was tired of arguing with people who knew nothing and were confrontational. He said he doesn't plan to post anymore and this a great loss as i have downloaded every circuit he posted.

Do I see a trend here?
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Old 13th August 2003, 04:32 PM   #16
jcx is offline jcx  United States
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Will someone point out what I did wrong?

I calculated the +Vcc2 DC value with the 2.2K series R18, assuming J2_Id = Q4_Ic ~ 15 mA (guessing that HZ15 is a 15 V zener - but since the current is set by (|Vcc1|-Q3_Vbe)/(R11+R3), everything is nearly ratiometric)

when I try to put 15 mA through the 2.2K R18 I get 33V, which is greater than the total supply voltage so I assume something must be satrutated, like J2, with the excess current comming from the forward biased gate-source diode
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Old 13th August 2003, 04:51 PM   #17
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Default Sorry JCX....

I was overly harsh in my previous posting. Please accept my apologies for over reacting.

When I look at a circuit, I primarily look at the overall topology and tend to ignore the component values. The topology is (as I previously posted) a complementary source follower driving a complementary emitter-follower. There is nothing whatsoever wrong with this circuit topology.

If we use the posted values, we do indeed find some oddities. Following your assumption (which seems a reasonable one) that HZ15 is a 15 volt zener, then it does appear that there will be something close to 15 mA of current coming from the current sources.

This is too much for these particular FETs, which are better off running in the range of 2 mA to 6 mA or so. There is also the problem that you correctly pointed out the voltage drop across the 2.2 k decoupling resistors in the power supply.

You reached the conclusion that the FETs had a reverse bias from gate-to-source, were only acting as forward-biased diodes, and should be removed from the circuit. I think this is jumping to an unwarranted conclusion. Even if the circuit were built with the values shown it wouldn't reverse-bias the FETs. It would, however, have some other problems.

I would instead assume that a typo was made somewhere along the way, and that the 750 resistors in the current sources should really be 7500 ohms. Or that the 2.2 k resistors in the power supply should really be 220 ohms. It's clear to me that the circuit was drawn by someone who has a good understanding of things. He may have made a typo, or the originator of this thread may have made a typo, but let's not throw out the baby with the bathwater.

I also disagree with many of the assertions you made in your earlier post, but I don't think getting into an argument of your opinion versus my opinion of the circuit is going to help the original poster get his circuit built.

Best regards,
Charles Hansen
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Old 13th August 2003, 05:38 PM   #18
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Angry Re: Knowledge doesn't count..........

Quote:
Originally posted by Fred Dieckmann
I got an Email from a very knowledgable
poster saying he was tired of arguing with people who knew nothing and were confrontational. He said he doesn't plan to post anymore and this a great loss as i have downloaded every circuit he posted.

Do I see a trend here?

Hi Fred,
It was not me who wrote you that e-mail but I could have been it as I agree 100 % with the sender.
I stopped posting at 999 posts as I had enough of the quarrels here but did resume posting as there was some confusion about my clock and ASR.
I get enough of commercial postings like "my clock is better than yours" and guys knowing it better all the time, posing as an expert.
I was under the impression this forum was for exchanging ideas and experiences NOT for proving who is "right" or has the "best" circuit.

In closing I am looking at my equipment and trying to sum up which ideas I got from this forum in exchange to mines...
In fact the result is very meager as I can only think of ultra-soft recovery diodes. An idea inspired by your high-speed diode thread.
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Old 13th August 2003, 06:46 PM   #19
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Default Re: Knowledge doesn't count..........

Quote:
Originally posted by Fred Dieckmann
I got an Email from a very knowledgable
poster saying he was tired of arguing with people who knew nothing and were confrontational. He said he doesn't plan to post anymore and this a great loss as i have downloaded every circuit he posted.
So it's ok to be confrontational provided you know something? Or apparently at least believe you know something? I'll jot that down for future reference. Thanks.

se
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Old 13th August 2003, 06:50 PM   #20
SY is offline SY  United States
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Guys, I'd really appreciate it if you'd stick to the technical issues and cut out the sniping. The technical portions are interesting and well-argued. The sniping back-and-forth is silly and childish. Let me add that if you want to argue about something that you posted in another forum, that other forum would be a more appropriate place for it.
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