Transistor booster design

Blocking oscillator boost converter:

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John

Reply to
John Larkin
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He is probably referring to the auto query engine (still going on every 3 minutes), but it's been IP filtered.

The problem is that both inductors are on and off at the same time, so it could not be more than 50% efficient.

Reply to
linnix

The IP belongs to google. After redirecting it to a big male enhencement picture, the search seems to be a little bit slower. The google engine is too busy looking at the picture? Any google Engineer here, not busy looking at other pictures?

If anyone else see the picture, I apologize.

Reply to
linnix

[snip]

Nope! I was making a rude comment about your circuit design "capabilities" ;-)

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

I know it's not great, but cost effective. No need to over-engineer a disposable product. As I said earlier, it will be packed with a battery. Why build a circuit to out-last a battery.

By the way, google stopped, after 2706 hits and over 2500 analysis on this circuit. Where do I send the bill?

Reply to
linnix

I suggest you "google" robots.txt

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John Devereux
Reply to
John Devereux

OK, thanks. But if I list a private directory, couldn't someone intentionally search them as well?

Reply to
linnix

WRONG.

Reply to
Winfield Hill

The file is only a "hint" to search engines, but they all should obey it. So I believe the directory would not be listed in google, but a person could still get to it if they know the URL.

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John Devereux
Reply to
John Devereux

But linnix said, "I know it's not great, but cost effective. No need to over-engineer a disposable product."

So it doesn't matter that he has no clue ;-)

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

OK, yes, there are out of phase. But power loss from the lower inductor will be significant.

I guess we can't hire you guys to design disposable products.

Reply to
linnix

"Cost effective" does not mean that it has to be "junk".

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

That's your opinion, thank you. As long as the junction degrades much slower than the battery, it is an acceptable and practical solution. I believe it is the case, and I will build some more prototype to check it out. I have one that works long enough to be usable for me.

Unlike John, you have not offer any alternative yet.

Reply to
linnix

It's a transformer with two windings, demonstrated by the "T1" on each. The windings are not equal, being a pretty hefty step-down in to the emitter. The feedback winding can be in the base, too, just about as good. A bit of series resistance in the base may be needed to better define peak base current, but a slick custom transformer could handle that, between copper ohms and leakage inductance.

One of the many cool things about a blocking oscillator it that the transformer is driven to saturation every time it's used, making optimum use of the core.

This should be very efficient if designed right.

Blocking oscillators were common in WWII vintage radars and tube-era test equipment, in and some of the early transistor stuff. But it didn't take long for transistors to get cheaper than transformers.

John

Reply to
John Larkin

I'm trying to make you think for yourself rather than just proffering the proper way to do it. Think of me as that professor that gave you a "D". He should have given you an "F" ;-)

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

OK, sound reasonable. I'll give it a try.

Reply to
linnix

Didn't we call the electromagnetic version of the blocking oscillator a ... vibrator?? Anybody remember that at the last hurrah of the wacuum tube they had ... solid state vibrator replacements???

Jim

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"If you think you can, or think you can\'t, you\'re right."
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Reply to
RST Engineering (jw)

Thank you for the grade. The circuit I posted is not my original design, so I won't feel bad about not using it. I can prototype both to try them out. We will have enough rooms for both (and more) circuits in the final chip, and then decide what to activiate. If we decide to use John's idea (whether it's his original design or not), we will send me enough beer and pizza to make him happy.

I will post the final chip design eventually. I don't think the customer would mind, since nobody else would be crazy enough to make this chip anyway. The customer is not in the chip business and they are only interested in one very specific application.

Reply to
linnix

Ok - I stand corrected - and I'm glad that you do enjoy. I agree that fun is understanding whys and why nots - but it is not limited to that, for me. You can enjoy reading about Esaki's work, but can't get the diodes for 7 cents to play with. But you can play with 2N2222's in the negative resistance region. And get a kick out of it. :-)

Understood.

Ed

Reply to
ehsjr

The problem with this approach is that even if your prototype(s) survive, when you go to production you may get a different batch of transistors which may not. You would not be trying so hard to be cheap if you were not considering high volume production for this. So in my opinion it is actually *more** important to have reliability in this situation than for some high-value custom industrial product. The potential for disaster is huge, since this is not the kind of product that can afford a service visit from an engineer to fix! You could end up with thousands of units out there, *all* of which fail.

Having said that, I admit I have lost track of which circuit is being criticised. The one I see here:

... does seem to have base protectiion diodes, so I guess it's OK with respect to junction zener damage.

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John Devereux
Reply to
John Devereux

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