Various Transistors Tested for Ic and Vce(sat)

[Watson A.Name - Watt Sun, Dark Remover]

I built the simple LED V Boost circuit at
http://www.elecdesign.com/Files/29/5886/Figure_01.gif 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 <at> 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@@

 

[Active8]

On Sat, 3 Jan 2004 20:03:43 -0800, Watson A.Name - "Watt Sun, Dark

I built the simple LED V Boost circuit at
http://www.elecdesign.com/Files/29/5886/Figure_01.gif 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.

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

 

[Tim Williams]

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

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

Tim

 

[Active8]

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

Tim

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.

 

[Jim Thompson]

I built the simple LED V Boost circuit at
http://www.elecdesign.com/Files/29/5886/Figure_01.gif 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.

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

Pretty sad "design".

...Jim Thompson

 

[Jim Thompson]

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

Pretty sad "design".

...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

 

[Baphomet]

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

 

[Jim Thompson]

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

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

 

[Watson A.Name - Watt Sun, Dark Remover]

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

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

Tim

--

--
@@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 <at> 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@@

 

[Watson A.Name - Watt Sun, Dark Remover]

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

Pretty sad "design".

Well, yeah - hey it's simple. The URL for the whole project,
including a technical explanation of circuit, is at
http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5886

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

...Jim Thompson

--
@@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 <at> 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@@

 

[Watson A.Name - Watt Sun, Dark Remover]

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

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 <at> 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@@

 

[Baphomet]

Is this a homework exercise?

As is much of life ;-)

 

[Watson A.Name - Watt Sun, Dark Remover]

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

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 <at> 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@@

 

[Jim Thompson]

[email protected] mentioned... [snip]

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

Is this a homework exercise?

Yes ;-)

...Jim Thompson

 

[Watson A.Name - Watt Sun, Dark Remover]

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

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 <at> 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@@

 

[Jim Thompson]

[email protected] mentioned... [snip]

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

Pretty sad "design".

Well, yeah - hey it's simple. The URL for the whole project,
including a technical explanation of circuit, is at
http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5886

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

...Jim Thompson

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

 

[Baphomet]

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

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.

 

[Jim Thompson]

[email protected] mentioned... [snip]

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

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.

(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

 

[Baphomet]

[email protected] mentioned... [snip]

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

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.

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

Will a slide rule do? ;-)

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

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

 

[Jim Thompson]

Will a slide rule do? ;-)

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".

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

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