1. Home
  2. General Electronics
  3. Various Transistors Tested for Ic and Vce(sat)

Various Transistors Tested for Ic and Vce(sat)

I built the simple LED V Boost circuit at

formatting link
except I used a BC338 for Q1 and added a 100 uF across the battery which is really a power supply. I paralleled three LEDs because at higher currents the single LED would overheat. I used a socket for Q2 so that I could test various transistors.

Here are the various transistors and the total supply current for each at 1.5VVDC. Nothing but the transistor was changed between tests. The idea here is to show how much better the low Vce(sat) transistors do in a flyback type circuit where a lot of current is switched.

2N3904 = 48 mA Can you spell W-I-M-P ??

2N4401 = 98 mA Supposed to handle a half amp.

BC338 = 132 mA Is good up to an Ic of 800 mA.

ZTX651 = 186 mA This has a max Ic of 2A

I couldn't test the BC639, 2SD965, and NTE11, etc., because the collector is the center pin and I would have to rewire the socket. I'll try these later, because they should do even better.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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
Loading thread data ...

Make a little converter board the reroutes the pins for you so you don't have to rewire the circuit every time you go from cbe to bce. or add a separate socket :)

--
Best Regards,
Mike
Reply to
Active8

Pffbbt.. just bend the pins around so they swap..don't short them :)

Tim

-- "That's for the courts to decide." - Homer Simpson Website @

formatting link

Reply to
Tim Williams

heh, heh. Try plbht. That's how I heard an IT mgr spelling it. I think he got it from the educational section (cartoons.)

I never did like bending leads around like that.

--
Best Regards,
Mike
Reply to
Active8

Can you write a technical description of how that circuit works?

Pretty sad "design".

...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

Please collect data as follows...

Measure beta of each device at the current you observed, with VCE=0.7

Also record duty cycle for each device.

...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

You've sure got that right. What the hell kind of circuit is that? No wonder the L.E.D. overheats!

Reply to
Baphomet

Yep, You can get upwards of 500mA peak into the LED with the "right" transistor.

I was just trying to introduce the concept of "analysis" into circuits of this sort.

Watson has hung his hat on VCE(sat) and that's only a small portion of the variability he's observing.

I am certain that Watson, and most lurkers here, *cannot* analyze (i.e. predict performance in advance of building) this circuit.

Fred Bloggs: Please hold your tongue so that I can incite some thinking... if you simply spit out the answer all my attempts at teaching people to think will be lost.

...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

In article , snipped-for-privacy@charter.net mentioned...

Like to see you try that with toobs!! ;-P

-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:###

formatting link
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).
formatting link
You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it:
formatting link

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

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

Well, yeah - hey it's simple. The URL for the whole project, including a technical explanation of circuit, is at

formatting link

If Electronic Design isn't the authority, then who else can you trust? ;-)

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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

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

Is this a homework exercise?

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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

As is much of life ;-)

Reply to
Baphomet

In article , snipped-for-privacy@no.spam.us mentioned...

Overheat? With a 2N3904? How? The 2N3904 might, since it's such a wimp.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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

[snip]

Yes ;-)

...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 | |

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

Reply to
Jim Thompson

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

I don't have a SPICE prog. Like Steve Ciarcia says, my favorite programming language is solder.

Hey the thing's sitting there, working. For the inductor, I used a Mouser #580-22R104.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###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

[snip]

Electronic Design an authority? ROTFLMAO!

Particularly got a kick out of "There's a limitation..." ;-)

That's nothing more than an *inaccurate* hand-waving.

The purpose of asking for the data-taking was to cause your mind to do a little correlation and then some further thought ;-)

For instance... what *is* saturation and what determines when a transistor will come out of saturation?

...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

a

the

each

transistors

wonder

Jim Thompson wrote

"Yep, You can get upwards of 500mA peak into the LED with the "right" transistor".

No mention was made of the 2N3904...just the "right" (or wrong depending upon your point of view) transistor.

Reply to
Baphomet

[snip]

(1) I didn't have in mind using Spice. Use pencil and paper. Remember that stuff?

(2) What is the definition of "working"... as you *predicted* before building it, or that it just happens to light the LED ?:-)

...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

Will a slide rule do? ;-)

I think the definition of this particular circuit working is when you see a plume of smoke rising from the L.E.D. and hear it screaming for mercy :-)

Reply to
Baphomet

Sure! I used to teach a course in how to use a slide rule. I still have my K&E in its green "leather" case with a belt clip ;-) Also a

*round* Post and a plastic "Acumath".

It *does* lack of predictability, but I suspect that's fixable.

I can eyeball the thing and see how it works, but it'll probably be tomorrow before I can put pencil-to-paper... I'm madly scrambling to finish a design review report.

...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

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.