J
John Larkin
Guest
On 5 Sep 2004 20:47:00 -0700, tatto0_2000@yahoo.com (Wong) wrote:
John
Aren't B and C the same node?
John
J
James D. Veale
Guest
You might want to check out
http://www.streamlight.com
http://www.flashlights.com
Streamlight makes a 2 AA Luxeon flashlight
and a dimmable 3 AAA Luxeon headlight. I believe the flashlight
has a DC-DC voltage converter, so it runs well on NiMH rechargeables.
"BruceW..1" <sorry@noDirectEmail.com> writes:
http://www.streamlight.com
http://www.flashlights.com
Streamlight makes a 2 AA Luxeon flashlight
and a dimmable 3 AAA Luxeon headlight. I believe the flashlight
has a DC-DC voltage converter, so it runs well on NiMH rechargeables.
"BruceW..1" <sorry@noDirectEmail.com> writes:
J
John Miller
Guest
Wong wrote:
directly connected.
--
John Miller
Email address: domain, n4vu.com; username, jsm
A diplomat is a man who can convince his wife she'd look stout in a fur
coat.
If the ASCII drawing is correct, B and C will always be the same; they are
directly connected.
--
John Miller
Email address: domain, n4vu.com; username, jsm
A diplomat is a man who can convince his wife she'd look stout in a fur
coat.
N
nospam
Guest
"BruceW..1" <sorry@noDirectEmail.com> wrote:
http://www.linear.com/prod/datasheet.html?datasheet=736
Looks like a useful part for this application. Unfortunately like most
switchers for portable applications it is only available in tiny surface
mount packages.
The Linear Technology LT1618
http://www.linear.com/prod/datasheet.html?datasheet=736
Looks like a useful part for this application. Unfortunately like most
switchers for portable applications it is only available in tiny surface
mount packages.
M
Michael A. Covington
Guest
Do you have a connection to ground in your circuit? Electronics Workbench
(Multisim) and similar simulators need one, in order to calculate voltages.
(Multisim) and similar simulators need one, in order to calculate voltages.
R
Randy Day
Guest
Wong wrote:
applied at point B. The resistance between B and C
is 0 ohms, so Vc will always equal Vb.
If you connect B to 5v, you're putting a 0 (that's zero)
ohm resistance in parallel with the upper 2k resistor.
What does your 'voltage divider rule' say about this?
If you connect B to A (0v), you're putting a 0 (that's zero)
ohm resistance in parallel with the *lower* 2k resistor.
What does your 'voltage divider rule' say about this?
This is correct, as long as *no voltage* is being
applied at point B. The resistance between B and C
is 0 ohms, so Vc will always equal Vb.
The voltage chart is correct for the circuit as drawn.
If you connect B to 5v, you're putting a 0 (that's zero)
ohm resistance in parallel with the upper 2k resistor.
What does your 'voltage divider rule' say about this?
If you connect B to A (0v), you're putting a 0 (that's zero)
ohm resistance in parallel with the *lower* 2k resistor.
What does your 'voltage divider rule' say about this?
J
John Larkin
Guest
On 6 Sep 2004 03:04:46 -0700, tatto0_2000@yahoo.com (Wong) wrote:
It would if nothing else is connected to it. But when you apply a hard
voltage source to the junction, the source wins.
Please don't top post.
John
It would if nothing else is connected to it. But when you apply a hard
voltage source to the junction, the source wins.
Please don't top post.
John
J
Jamie
Guest
eh?
Point B and C are connected! why shouldn't they be the same?
just think about that.
if Point B is applied voltage from a source its ovbious that
Point C will look the same.
Wong wrote:
Point B and C are connected! why shouldn't they be the same?
just think about that.
if Point B is applied voltage from a source its ovbious that
Point C will look the same.
Wong wrote:
J
Joerg
Guest
Hi,
ground plane. I would probably spring for a relayout with a full ground
plane even if that means one or two more layers on the boards. The other
issue with this unit might be EMC, especially with a plastic enclosure.
Regards, Joerg
http://www.analogconsultants.com
hard to make a RF/controller combination work reliably without a full
ground plane. I would probably spring for a relayout with a full ground
plane even if that means one or two more layers on the boards. The other
issue with this unit might be EMC, especially with a plastic enclosure.
Regards, Joerg
http://www.analogconsultants.com
R
Randy Day
Guest
Navid Naghdi wrote:
This ain't alt.get.your.homework.done.for.free, son.
Crack open your textbook, show us *your* design and
we'll critique it...
<sigh> Is it that time of year already?
This ain't alt.get.your.homework.done.for.free, son.
Crack open your textbook, show us *your* design and
we'll critique it...
I
Ian Stirling
Guest
In sci.electronics.design BruceW..1 <sorry@nodirectemail.com> wrote:
peak current at 350ma.
at a battery voltage of 2.4V, rather than 1.2V.
You can probably get away with a step-up only device, 2 fresh alkaline AA
cells won't provide enough current at ~3.5V to kill the luxeon device, even
neglecting diode drops.
Synch rectification will buy you a little bit, but not much.
It'll put out a lot more light at low average currents if you keep the
peak current at 350ma.
For most of the SMPS chips available, they are significantly more efficient
at a battery voltage of 2.4V, rather than 1.2V.
You can probably get away with a step-up only device, 2 fresh alkaline AA
cells won't provide enough current at ~3.5V to kill the luxeon device, even
neglecting diode drops.
Synch rectification will buy you a little bit, but not much.
I
Ian Stirling
Guest
In sci.electronics.design Ian Stirling <root@mauve.demon.co.uk> wrote:
2 AA 1.5V cells, and 1AA 3V cell, for emergencies.
What may also be useful would be a 3 cell device.
2 AA 1.5V cells, and 1AA 3V cell, for emergencies.
T
the Wiz
Guest
zoid999@excite.com (Navid Naghdi) wrote:
More about me: http://www.jecarter.com/
VB3/VB6/C/PowerBasic source code: http://www.jecarter.com/programs.html
Freeware for the Palm with NS Basic source code: http://nsb.jecarter.com
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
Email here: http://www.jecarter.com/contactme.htm
Sounds like you need to review the concepts of series and parallel...
More about me: http://www.jecarter.com/
VB3/VB6/C/PowerBasic source code: http://www.jecarter.com/programs.html
Freeware for the Palm with NS Basic source code: http://nsb.jecarter.com
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
Email here: http://www.jecarter.com/contactme.htm
D
Don Klipstein
Guest
In article <413ce387$0$24441$ed2619ec@ptn-nntp-reader03.plus.net>, Ian
Stirling wrote in part:
maximized at instantaneous currents somewhat less, maybe around 200 mA.
For white and blue ones, the efficiency is maximized at even lower
instantaneous currents around 100 mA or less.
If your average current is around or over 50 mA and the Luxeon is a
white one, I recommend steady rather than pulsating current. But if the
average current is only a few milliamps, then you are better off using
pulses with a higher instantaneous current - perhaps 50-100 mA.
- Don Klipstein (don@misty.com)
Stirling wrote in part:
I have found the efficiency of red, orange and yellow Luxeons to be
maximized at instantaneous currents somewhat less, maybe around 200 mA.
For white and blue ones, the efficiency is maximized at even lower
instantaneous currents around 100 mA or less.
If your average current is around or over 50 mA and the Luxeon is a
white one, I recommend steady rather than pulsating current. But if the
average current is only a few milliamps, then you are better off using
pulses with a higher instantaneous current - perhaps 50-100 mA.
- Don Klipstein (don@misty.com)
M
Michael A. Covington
Guest
Which professor assigned this as your homework?
This is not a very difficult problem. I'm not sure why you're asking for
help.
"Navid Naghdi" <zoid999@excite.com> wrote in message
news:26278ab4.0409061301.43bc2d8f@posting.google.com...
This is not a very difficult problem. I'm not sure why you're asking for
help.
"Navid Naghdi" <zoid999@excite.com> wrote in message
news:26278ab4.0409061301.43bc2d8f@posting.google.com...
R
Rich Grise
Guest
Rich Webb wrote:
3-lobed rotor of a Wankel engine, but rounded, of course. I remember
when I was quite young that there was an announcement that scientists
had discovered that the earth bulged, but that the bulge is south of
the equator. And it's kind of elongated at the north pole. One thing
that makes this kinda cool for me is that one time in the USAF I was
BSing with some guy who turned out to be in on the early missile tests
where they discovered the bulge. He said that there was this one series
of flights that kept landing short and to the south of where they had
calculated. (or short and north, whatever). He also said that in one
of their experiments they put a whole rocket in orbit, like, one stage.
At the time, I had thought that that was impossible, like everybody
else. Presumably, it's still up there.
Cheers!
Rich
A profile view of the earth, exaggerated, would look like the
3-lobed rotor of a Wankel engine, but rounded, of course. I remember
when I was quite young that there was an announcement that scientists
had discovered that the earth bulged, but that the bulge is south of
the equator. And it's kind of elongated at the north pole. One thing
that makes this kinda cool for me is that one time in the USAF I was
BSing with some guy who turned out to be in on the early missile tests
where they discovered the bulge. He said that there was this one series
of flights that kept landing short and to the south of where they had
calculated. (or short and north, whatever). He also said that in one
of their experiments they put a whole rocket in orbit, like, one stage.
At the time, I had thought that that was impossible, like everybody
else. Presumably, it's still up there.
Cheers!
Rich
J
Joe
Guest
Rodney,
For great circle distance computations it goes like this:
Distance = 69.1 x (180/pi) x arccos | sin(lat1) x sin(lat2) + cos(lat1) x
cos(lat2) x cos(long2 - long1) |
M
Michael A. Covington
Guest
"billy_evil" <billy_evil@yahoo.com> wrote in message
news:bbd2a5b4.0409061853.1cf01d6b@posting.google.com...
news:bbd2a5b4.0409061853.1cf01d6b@posting.google.com...
Size of the registers.
B
Bob
Guest
I can't do it. I really want to, though.
Bob
G
Gary Richardson
Guest
[snip]
You might try my ascii schematic drawing program. I think you will find it
easier to use than Andy's and it has a few more features.
It's at www.fidalgo.net/~garyr/pyascii/
The executable and associated files are in PyAscii_04_Win9x.zip (~ 2 MB)
The source files are in PyAscii_04_source.zip
Just click on the filename to start the download.
Gary Richardson
You might try my ascii schematic drawing program. I think you will find it
easier to use than Andy's and it has a few more features.
It's at www.fidalgo.net/~garyr/pyascii/
The executable and associated files are in PyAscii_04_Win9x.zip (~ 2 MB)
The source files are in PyAscii_04_source.zip
Just click on the filename to start the download.
Gary Richardson