1.5v to 3.3v LED circuit
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1.5v to 3.3v LED circuit
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LED Man
Guest
Posted: Sat Feb 19, 2005 6:10 am    Post subject: 1.5v to 3.3v LED circuit Reply with quote
Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit, or
single chip device

TIA

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Robert Monsen
Guest
Posted: Sat Feb 19, 2005 6:10 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
LED Man wrote:
Quote:
Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit, or
single chip device

TIA

http://tinyurl.com/5843f

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.
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Jonathan Kirwan
Guest
Posted: Sat Feb 19, 2005 3:16 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
On Sat, 19 Feb 2005 03:31:40 GMT, LEDMan@3v.invalid (LED Man) wrote:

Quote:
Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit, or
single chip device

An NPN, a 1.5V AA battery, two resistors, a capacitor, a diode and a simple,
hand-wound threaded toroidal. D2 can be a diode-connected 2N3904, a 1N4148, or
a Schottky like a 1N5817-1N5819.

V+ V+ V+
| | |
| | |
| )|. .|( (about 50" of
| )| |( magnet wire
| )| T1 |( for both
| + )| |( windings)
--- | |
- B1 | | D2 R2
--- \ +---|>|---+---/\/\---,
- / R1 | | 220 |
| \ 2200 | | |
| / | | |
| | |/c Q1 | --- ~
| '------| 2N3904 --- C1 \ / ~
| |>e --- 100uF --- LED
| (B1 > 1V) | | |
| | | |
gnd gnd gnd gnd

It will drain a AA battery fairly completely, before quitting.

Jon

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RST Engineering (jw)
Guest
Posted: Sat Feb 19, 2005 10:53 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
Jon...

I have a hell of a time with ASCII schematics. Could you possibly post a
"real" schematic to alt.binaries.schematics.electronic?

Jim



"Jonathan Kirwan" <jkirwan@easystreet.com> wrote in message
news:g0nd1197fcaof5kb1je9i90vpe1irqdgbs@4ax.com...
Quote:
On Sat, 19 Feb 2005 03:31:40 GMT, LEDMan@3v.invalid (LED Man) wrote:

Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit, or
single chip device
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CWatters
Guest
Posted: Sun Feb 20, 2005 12:29 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
"RST Engineering (jw)" <jim@rstengineering.com> wrote in message
news:111erncf6rkh4ab@corp.supernews.com...
Quote:
Jon...

I have a hell of a time with ASCII schematics.

copy into notepad and then format -> font -> "fixedsys"
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Rich Grise
Guest
Posted: Sun Feb 20, 2005 2:25 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
On Sat, 19 Feb 2005 18:29:20 +0000, CWatters wrote:

Quote:

"RST Engineering (jw)" <jim@rstengineering.com> wrote in message
news:111erncf6rkh4ab@corp.supernews.com...
Jon...

I have a hell of a time with ASCII schematics.

copy into notepad and then format -> font -> "fixedsys"

You should be able to set your newsreader for a fixed font. I use
Courier.

Cheers!
Rich
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RST Engineering (jw)
Guest
Posted: Sun Feb 20, 2005 3:10 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
I have Courier as my default font and I still have a hell of a time reading
an ASCII schematic. Sorry.

Jim



"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.02.19.20.25.30.17968@example.net...
Quote:
On Sat, 19 Feb 2005 18:29:20 +0000, CWatters wrote:


"RST Engineering (jw)" <jim@rstengineering.com> wrote in message
news:111erncf6rkh4ab@corp.supernews.com...
Jon...

I have a hell of a time with ASCII schematics.

copy into notepad and then format -> font -> "fixedsys"

You should be able to set your newsreader for a fixed font. I use
Courier.

Cheers!
Rich

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Jonathan Kirwan
Guest
Posted: Sun Feb 20, 2005 6:06 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
On Sat, 19 Feb 2005 08:53:09 -0800, "RST Engineering \(jw\)"
<jim@rstengineering.com> wrote:

Quote:
I have a hell of a time with ASCII schematics.

Is it an inability to recognize the symbols?

I guess I'm asking this because it took me exactly zero time to see and
understand an ASCII schematic the first time I saw one and I've had very little
trouble ever after, so I'm honestly curious about what makes this difficult for
some -- I completely lack the personal experience to understand the trouble, so
I'd appreciate any clues about what you perceive and don't perceive.

Meanwhile, I'll try and load over a schematic in some format you can see. I
have a few other things to take care of before I struggle with that, though.

Jon
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petrus bitbyter
Guest
Posted: Sun Feb 20, 2005 6:10 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
"LED Man" <LEDMan@3v.invalid> schreef in bericht
news:1gs7o6k.2zw8mq1hphlgwN%LEDMan@3v.invalid...
Quote:
Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit, or
single chip device

TIA



http://www.qsl.net/yo5ofh/hobby%20circuits/led_circuits.htm
http://users.cableaz.com/~cappels/dproj/ledpage/leddrv.htm
http://www.discovercircuits.com/PDF-FILES/ac14fls.pdf
http://repairfaq.ece.drexel.edu/sam/bledl1.gif

Just some google results. There are much more of them.

petrus bitbyter
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Rich Grise
Guest
Posted: Sun Feb 20, 2005 1:53 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
On Sat, 19 Feb 2005 13:10:59 -0800, RST Engineering (jw) wrote:

Quote:
I have Courier as my default font and I still have a hell of a time reading
an ASCII schematic. Sorry.


I'll have to throw in with petrus here, then. What's the hard part?

Do your ASCII schematics not look like this one?:
http://www.neodruid.net/images/ASCII_Art.jpg

Good Luck!
Rich
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RST Engineering (jw)
Guest
Posted: Sun Feb 20, 2005 9:18 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
No, they don't. The link you sent was quite readable. The schematic in
this newsreader was highly compressed in the x dimension and absolutely
unreadable. However, as I sit here and look, the fact that I've got my
settings to Courier doesn't seem to make a difference. Just looking at this
font I can tell it is a variant of Helvetica, or Arial, or whatever other
san-serif font you want to call it.

I need to do some more investigation as to why it looks like this. Or
perhaps only the OUTGOING messages look like this...

Thanks,

Jim


"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.02.20.07.53.24.623692@example.net...


Quote:
Do your ASCII schematics not look like this one?:
http://www.neodruid.net/images/ASCII_Art.jpg

Good Luck!
Rich
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RST Engineering (jw)
Guest
Posted: Sun Feb 20, 2005 9:23 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
Lordy, Outlook Express makes you change the font in no less than THREE
places in order to force messages to Courier. THe default fixed width, the
default proportional width, and the little checkbox on the "advanced" tab to
default all incoming messages to the default settings.

Windoze does it again.

Thanks for the help, Rich...

Jim


"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.02.20.07.53.24.623692@example.net...
Quote:
On Sat, 19 Feb 2005 13:10:59 -0800, RST Engineering (jw) wrote:

I have Courier as my default font and I still have a hell of a time
reading
an ASCII schematic. Sorry.


I'll have to throw in with petrus here, then. What's the hard part?

Do your ASCII schematics not look like this one?:
http://www.neodruid.net/images/ASCII_Art.jpg

Good Luck!
Rich
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Lord Garth
Guest
Posted: Sun Feb 20, 2005 10:30 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
"RST Engineering (jw)" <jim@rstengineering.com> wrote in message
news:111hars36bo1t7a@corp.supernews.com...
Quote:
Lordy, Outlook Express makes you change the font in no less than THREE
places in order to force messages to Courier. THe default fixed width,
the
default proportional width, and the little checkbox on the "advanced" tab
to
default all incoming messages to the default settings.

Windoze does it again.

Thanks for the help, Rich...

Jim


If you use OE and the font is not set to default to a fixed width font, you
can
select 'view' then move down to 'text size' then move to 'fixed' to see it
on the
ASCII art on the fly.
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Clarence_A
Guest
Posted: Sun Feb 20, 2005 11:34 pm    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
Quote:
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.02.20.07.53.24.623692@example.net...
Do your ASCII schematics not look like this one?:
http://www.neodruid.net/images/ASCII_Art.jpg
Good Luck!
Rich
"RST Engineering (jw)" <jim@rstengineering.com> wrote in message

news:111hah4ii32gk4d@corp.supernews.com...
Quote:
No, they don't. The link you sent was quite readable. The
schematic in
this newsreader was highly compressed in the x dimension and
absolutely
unreadable. However, as I sit here and look, the fact that I've
got my
settings to Courier doesn't seem to make a difference. Just
looking at this
font I can tell it is a variant of Helvetica, or Arial, or
whatever other
san-serif font you want to call it.

I need to do some more investigation as to why it looks like
this. Or
perhaps only the OUTGOING messages look like this...

Thanks, Jim

GMAB
Why bother to explain, He's a top poster, his inability to
understand anything is clear. He thinks upside down! (:>)
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Watson A.Name - \"Watt Su
Guest
Posted: Mon Feb 21, 2005 2:15 am    Post subject: Re: 1.5v to 3.3v LED circuit Reply with quote
"Jonathan Kirwan" <jkirwan@easystreet.com> wrote in message
news:g0nd1197fcaof5kb1je9i90vpe1irqdgbs@4ax.com...
Quote:
On Sat, 19 Feb 2005 03:31:40 GMT, LEDMan@3v.invalid (LED Man) wrote:

Looking to drive a white superbright led (1-4) from 1.5v to 2.5v
battery, led requires 3.3v @ 20ma, is there a suitable small circuit,
or
single chip device

An NPN, a 1.5V AA battery, two resistors, a capacitor, a diode and a
simple,
hand-wound threaded toroidal. D2 can be a diode-connected 2N3904, a
1N4148, or
a Schottky like a 1N5817-1N5819.

V+ V+ V+
| | |
| | |
| )|. .|( (about 50" of
| )| |( magnet wire
| )| T1 |( for both
| + )| |( windings)
--- | |
- B1 | | D2 R2
--- \ +---|>|---+---/\/\---,
- / R1 | | 220 |
| \ 2200 | | |
| / | | |
| | |/c Q1 | --- ~
| '------| 2N3904 --- C1 \ / ~
| |>e --- 100uF --- LED
| (B1 > 1V) | | |
| | | |
gnd gnd gnd gnd

It will drain a AA battery fairly completely, before quitting.

I really despise those who suggest that the 2N3904 is capable of doing
this job adequately. With that wimpy transistor, you will be lucky to
get enough current to power the LED at 8mA. Use a 2N4401 or the BC337.
Or if you want to get a lot more current, try the 2SD965 or NTE11. If
you can get some disposable flash cameras from your neighborhood
drugstore or photo shop, the flash inverter uses this kind of
transistor, and makes a great source for free transistors.

The above circuit is okay, but since the LED _is_ a diode, you don't
need the D2 and C2 filter cap, just connect the LED across the emitter
and collector. And R1 will have to be lower, probably 1k, if you use
something better than the 2N3904. The 2N3904 won't cut it with even a
470, it'll just get hot and poof. And whatthe hell is R2 there for?
That's just wasting power and ruining the efficiency!

> Jon
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