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Various Transistors Tested for Ic and Vce(sat)

In article , snipped-for-privacy@invalid.invalid mentioned...

Well, that's why I included the smiley.

IIRC, saturation is the point where Ic has reached its maximum value, and further increases in Ib won't increase Ic. THe .7 or so V between emitter and base (assuming an NPN) is a half volt or more greater than the < .2V collector to emitter, so the collector-base junction is on the verge of being forward biased. So more and more collector current 'leaks' into the base.

When the collector-base junction is no longer forward biased, then the transistor is no longer in saturation.

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Reply to
Watson A.Name - "Watt Sun, Dar
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In article , snipped-for-privacy@invalid.invalid mentioned...

Authority? These were submitted to them by readers, ElecDesign had little to do with them. That's why I put the smiley in there.

When Vce(sat) at higher currents is low, it minimizes the amount of power wasted in the transistor. Better efficiency.

I've said that transistors like the 2N3904 don't have good beta holdup at higher currents. The 2N4401, BC338, and ZTX651 have increasing beta holdups at higher currents.

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Reply to
Watson A.Name - "Watt Sun, Dar

[snip]

ISTR that the editor glowingly endorsed the "design".

You are *wrong* in using the term "beta holdup at higher current". But if you had said the 2N3904 has a lower beta than the ZTX651 you would have been correct.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
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Reply to
Jim Thompson

[snip]

^^^^^^^^^^^^^^^^^ CAN'T increase collector current due to OTHER circuit restraints.

Re-evaluate your statement for the case of VCE = 10V, for instance.

Actually more *base* current "leaks" into the collector, killing the base drive.

That is a correct statement.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

Hi Jim,

Electronic Design used to have a design hints contest, and one of the hints contained this design snippet:

+5V | | O | O | +------some gate or another... | O | O | | GND

-Chuck Harris

Jim Thompson wrote: TFLMAO!

Reply to
Chuck Harris

Labelled as what, an incendiary trigger mechanism?

No it's the self destruct off the Enterprise (buttons more than 6 ft apart please), needs two people to authorise.

Reply to
Mjolinor

I have used something very close to that on a low power micro circuit. The big difference was that the switches were the normally open and normally closed sections of a single snap switch. The micro input capacitance held the last closure voltage until the other switch closed the first time. No bounce and no current consumption, except for capacitive charging current. And noise immune in both states.

--
John Popelish
Reply to
John Popelish

Where is your sense of adventure? Don't your power supplies have over current shutdown? ;-)

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

I have posted BetaCurves.pdf on the S.E.D/Schematics page of my website.

I have run beta (DC, beta=IC/IB) curves for the four transistors that Watson tried in his (yet another :) LED driver.

I show beta curves versus current for various VCE conditions.

Hope this is useful.

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson

How is it immune to noise?

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Reply to
Tom Del Rosso

ed has, at the top of every cover,

The Authority on Emerging Technologies for Design Solutions

which is pretty fatheaded considering the actual contents. Most of the articles are product flacks, and the Design Briefs are usually stupid.

The technology articles often emphasize how hard it is to design stuff, so you'd be better off just buying it. Pease is down to one or two interesting columns per year.

And after we almost recovered from everything being a 'solution', now every other ad screams 'Size Matters'

Snarl. Need more coffee.

John

Reply to
John Larkin

When he taps it you're supposed to kneel and kiss the ring.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

Yeah, it's too bad about Pease. Too much time in Tibet.

Is it even possible for people occupied as writers to have anything to say about design that you would find useful?

It's what you do with your solution that counts.

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Reply to
Tom Del Rosso

There ya go! ROTFLMAO!

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

John/Watson/Watt Sun can hack to his heart's content. But what Watson needs is a little experience in manufacturing to functionality with minimum cost ;-)

I object to "explanations" that don't fit the facts. So I will post my objections, and correct the explanations, so that those lurkers wishing to learn can do so.

Actually, I prefer a world where virtually no one understands *why* things work... keeps me employed ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

[snip]

But some are down-right hilarious!

Yep. He's getting like me, talking more about the Potassium tablets he's taking than circuits ;-)

Hee! Hee!

We just got one of those coffee machines (Cuisinart) that puts the coffee into a vacuum-bottle carafe. Works great. I'm having a cup right now that was made 4.5 hours ago... still hot and tasty, not bitter!

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.
Reply to
Jim Thompson

I just walk a block down 9th Avenue to The Beanery. They start foaming up a latte as soon as they see me walk in the door.

John

Reply to
John Larkin

In either the up or down state, the input signal is connected directoy to a supply bus, so capacitively coupled noise goes there, instead of into the micro. If I used a single switch and a high value resistor (to save battery current) capacitive noise could easily get to the micro when the switch was open.

Reply to
John Popelish

Gotcha. I thought you meant momentary both ways with a center return, more like the preceding example with the 2 buttons.

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Reply to
Tom Del Rosso

In article , snipped-for-privacy@invalid.invalid mentioned...

Well, here's a 6021 toob that has wire leads, but you can just see a little bit of them on the left.

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Better pic, and some data
formatting link 

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###Got a Question about ELECTRONICS?   Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted.  *All* email sent to it 
goes directly to the trash unless you add NOSPAM in the 
Subject: line with other stuff.  alondra101  hotmail.com
Don't be ripped off by the big book dealers.  Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com  You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Reply to
Watson A.Name - "Watt Sun, Dar

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