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mrdarr...@gmail.com wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly specified
parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
Thanks,
Michael
No, it wouldn't work at all, unless what you have in
mind is different than what you seem to be saying.
Give us a schematic of what you are thinking about.
Ed
assembly from broken harddisks, and attaching 2 ledsOn Dec 19, 11:37 pm, ehsjr <eh...@NOSPAMverizon.net> wrote:
mrdarr...@gmail.com wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly specified
parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
Thanks,
Michael
No, it wouldn't work at all, unless what you have in
mind is different than what you seem to be saying.
Give us a schematic of what you are thinking about.
Ed
Homemade shake-generator (plastic can, coils of wire outside, magnet
inside), bridge rectifier (Schottky?), capacitor, boost converter, LED
Michael
I have done what you intended, removing the magnet/coil
get a stronger magnet, and/or use more turns in the coil.Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Well you can't do that with silicon (look at Vbe vs Ic)and you may have someEeyore <rabbitsfriendsandrelati...@hotmail.com> wrote:
mrdarr...@gmail.com wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
Vbe ?
Yes.
Read up on device physics !Funny. I would have thought they are common.
Yup.Guess I was wrong.
Put more turns on the coil. Easy. And use Schottky diodes.Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
On Dec 19, 8:59 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 18:49:06 -0800, mrdarrett wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly
specified parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at
saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
You probably won't be able to detect the difference in collector current
between Vbe = 0 and Vbe = 0.1, at least with a Silicon transistor. Even
a Germanium transistor really needs a Vbe of around 0.3V. So there's not
much difference here between using a 2N3904 and a lump of clay.
You ask for the impossible. Explain what you _really_ want to do, and
someone may be able to help you out.
Funny. I would have thought they are common. Guess I was wrong.
Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Michael
use a op-amp to increase the level.
And in addition to what Graham said, a regular diode will do just fine tomrdarrett@gmail.com wrote:
Funny. I would have thought they are common.
Read up on device physics !
Guess I was wrong.
Yup.
Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I can't
use normal diodes (0.7V drop... oh well...)
Put more turns on the coil. Easy. And use Schottky diodes.
Graham
Its simply a matter of biasing the transistor to a suitable operating pointOn Dec 19, 8:59 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 18:49:06 -0800, mrdarrett wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly
specified parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at
saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
You probably won't be able to detect the difference in collector current
between Vbe = 0 and Vbe = 0.1, at least with a Silicon transistor. Even
a Germanium transistor really needs a Vbe of around 0.3V. So there's not
much difference here between using a 2N3904 and a lump of clay.
You ask for the impossible. Explain what you _really_ want to do, and
someone may be able to help you out.
Funny. I would have thought they are common. Guess I was wrong.
Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Michael
What an amazingly stupid comment !use a op-amp to increase the level.
Yes, I did. And I have the 'S level' to prove it.Study regular physics before you get to device physics...
Jamie wrote:
use a op-amp to increase the level.
What an amazingly stupid comment !
How many op-amps run on 100mV ?
Graham
What a twit you are..!
GO FUCK YOURSELF.Eeyore wrote:
Jamie wrote:
use a op-amp to increase the level.
What an amazingly stupid comment !
How many op-amps run on 100mV ?
Graham
What a twit you are..!
why don't you include the text I replied to, you
british ignoramus.
Jamie wrote:
Eeyore wrote:
Jamie wrote:
use a op-amp to increase the level.
What an amazingly stupid comment !
How many op-amps run on 100mV ?
Graham
What a twit you are..!
why don't you include the text I replied to, you
british ignoramus.
GO FUCK YOURSELF.
I thought so.
mrdarr...@gmail.com wrote:
On Dec 19, 11:37 pm, ehsjr <eh...@NOSPAMverizon.net> wrote:
mrdarr...@gmail.com wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly specified
parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
Thanks,
Michael
No, it wouldn't work at all, unless what you have in
mind is different than what you seem to be saying.
Give us a schematic of what you are thinking about.
Ed
Homemade shake-generator (plastic can, coils of wire outside, magnet
inside), bridge rectifier (Schottky?), capacitor, boost converter, LED
Michael
I have done what you intended, removing the magnet/coil
assembly from broken harddisks, and attaching 2 leds
antiparallel to the coil ends.
No need for rectifying, or boosting, just wiggle the coil
were it used to be, and the leds will light just fine.
Also interesting is, to shortcircuit the coil, and try to move
it, it acts as if inserted in syrup.
If you want more voltage from it use a small transformer.
using the primary as output, you get all the voltage you want.
You're kidding, right?Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Michael
use a op-amp to increase the level.
The comment was for the OP.Tim Wescott wrote:
Study regular physics before you get to device physics...
Yes, I did. And I have the 'S level' to prove it.
http://en.wikipedia.org/wiki/Scholarship_Level I only got 'Merit' though
due to the astonishing lack lack of electronics in that year's paper.
Semiconductor Physics was one of my favourite courses at UCL. Everyone
else positively HATED it.
Graham
I appreciate that. I was just adding my tuppence worth.Eeyore wrote:
Tim Wescott wrote:
Study regular physics before you get to device physics...
Yes, I did. And I have the 'S level' to prove it.
http://en.wikipedia.org/wiki/Scholarship_Level I only got 'Merit' though
due to the astonishing lack lack of electronics in that year's paper.
Semiconductor Physics was one of my favourite courses at UCL. Everyone
else positively HATED it.
The comment was for the OP.
Universities can have some funny ideas !And I liked the semiconductor physics classes, too -- the only things
that kept me from diverting to a chip designer was that at the time
Portland State University thought "chip" meant "digital" and I'd already
decided I wanted to do control systems.
On 2008-12-20, Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Michael
use a op-amp to increase the level.
You're kidding, right?
No, I'm not kidding.
like this?Jasen Betts wrote:
On 2008-12-20, Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:
Anyhow... I was thinking of making some sort of super-tiny electric
generator (basically just a magnet loosely moving inside a coil of
wire), and boosting that up to, oh, 1 volt or so, to light up an LED.
Another challenge would be to rectify the tiny current... guess I
can't use normal diodes (0.7V drop... oh well...)
Michael
use a op-amp to increase the level.
You're kidding, right?
No, I'm not kidding.
0.1V might be a challenge but I did get one to work at 0.2V withoutOn Fri, 19 Dec 2008 18:49:06 -0800 (PST), mrdarrett@gmail.com wrote:
On Dec 19, 4:19 pm, Tim Wescott <t...@seemywebsite.com> wrote:
On Fri, 19 Dec 2008 13:45:04 -0800, mrdarrett wrote:
Anyone recommend any NPN transistors with around 0.1-0.3VBE sat. ?
I did a mouser search but apparently Vbe sat. isn't a commonly specified
parameter... ?
Thanks,
Michael
Base to emitter voltage at saturation?
Yes, that.
Or do you mean Vce_sat, the _collector_ to emitter voltage at saturation?
No, not that.
Zetex and others make the latter in small sizes. The former can't be
done in silicon.
Ah.
Mr. Larkin had an interesting idea. If I wanted to say power a boost
converter (0.1 V to 1V) could I just feed the 0.1V to the base of my,
eh, 2N3904 NPN and it would work (at just incredibly low efficiency,
since it's not in saturation)?
0.1 volts on the base of a bipolar wouldn't do much of anything.
A 0.1 volt input boost converter would be a challenge. The easy way
would be to bootstrap it with a battery. Or a solar cell.
There are also zero volt threshold MOSFETs, Mouser has them (or at leastYou might be able to make an oscillator, at 0.1 volts, from a
depletion-mode gaasfet. Maybe.
That really angered me as a kid. Almost every cookbook containedToo bad you can't get tunnel diodes any more.