Driver to drive?

They always told me 'there is no such thing as peak to peak voltage'. At one
instant, there is a positive peak voltage, and at some other instant, there is
a negative peak voltage, but the voltage is a function, and only has one value
at an instant in time. Now lets argue about whether the product of rms voltage
and rms current is rms power or average power.....
 
Mark Evans wrote:

That's because the human brain is good at speach recognition...
Click to expand...
even better at speEch recognition....

--
e-crime and computer evidence conference
2005 - Coumbus Hotel, Monaco
http://www.ecce-conference.com/
 
Hi Frank,

In case the 9V doesn't come on fast enough it may not pulse.

I'd do this with a hex Schmitt trigger such as the 40106, a few RC and a
BSS123 if the opto need lots of oompf. It is cheap and you'd have some
spare inverters to play with. Sorry, don't have an ASCII editor and no
time to draw one up but should be easy. The datasheet shows how to make
one-shots and stuff with these.

Regards, Joerg

http://www.analogconsultants.com
 
Clarence wrote:
"Jean T?r?metz" <jean.teremetz@free.fr> wrote in message
news:8216c56.0410170755.456c8471@posting.google.com...


MORE SPAM and a possible Virus. Don't fall for it.
Click to expand...
let me tell you that I am sick and tired of those
judgmental folks that think I a brutish clod who
actually enjoys bending, refracting, and diffracting
light and forcing to run through little wave guides.

Heck no, I'm a sensitive guy, and I go home at night
and I cry to wife that I will never know at last what
are light and electricity.

--
local optimization seldom leads to global optimization

my e-mail address is: <my first name> <my last name> AT mmm DOT com
 
On 18 Oct 2004 20:57:18 GMT, bobgardner@aol.comma (BobGardner) wrote:

They always told me 'there is no such thing as peak to peak voltage'. At one
instant, there is a positive peak voltage, and at some other instant, there is
a negative peak voltage, but the voltage is a function, and only has one value
at an instant in time. Now lets argue about whether the product of rms voltage
and rms current is rms power or average power.....
Click to expand...
Track down, on a.b.s.e, the following post....

Peak-to-Peak Detector (S.E.D) - Peak-to-Peak-Detector.pdf
From: Jim Thompson Date: Tue, 21 Sep 2004 18:18:54 -0700 Size: 30.9k

...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.
 
"Roy Common" <rbmccammon@mmm.com> wrote in message
news:41744942.9090509@mmm.com...
Clarence wrote:
"Jean TO?or?Metz" <jean.teremetz@free.fr> wrote in message
news:8216c56.0410170755.456c8471@posting.google.com...

MORE SPAM and a possible Virus. Don't fall for it.

let me tell you that I am sick and tired of those
judgmental folks that think I a brutish clod who
actually enjoys bending, refracting, and diffracting
light and forcing to run through little wave guides.
Click to expand...
<snip>

I see a lot of people who shoot electrons down a evacuated tube. Most of them
never provide any useful data. This is not a group who delves into "Basic"
research. Many here build useful things!

Go somewhere playing with physics is a sport.
 
I wanted a nice slow time constant rms agc so I could keep from burning up
speakers. The time const was several seconds, so the peaks would go thru, but
the rms was 'how hot' the voicecoil was.
Set it at 100W and let it ride. Turns out, the rms was always about 3db above
the avg, so that was good enough.
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:pOXcd.15653$nj.5764@newssvr13.news.prodigy.com...
| Hi Frank,
|
| In case the 9V doesn't come on fast enough it may not pulse.
|
| I'd do this with a hex Schmitt trigger such as the 40106, a few RC and a
| BSS123 if the opto need lots of oompf. It is cheap and you'd have some
| spare inverters to play with. Sorry, don't have an ASCII editor and no
| time to draw one up but should be easy. The datasheet shows how to make
| one-shots and stuff with these.
|
| Regards, Joerg
|
| http://www.analogconsultants.com

You are a total and utter bastard.

At the prescribed end of the world you would break into the meeting between
the president of the USA (whomever that might fucking be) and his TOP
scientific advisors and say......

'I can do that with a 40106 and a few RC'

They would laugh quietly and have you removed from the room.

You would dial a taxi and go and install a 40106 and a few RC somewhere or
another and the crisis would be over.

What's it like to be seriously dangerous and where can I get the datasheet?

DNA
 
"Bob Dang" <msucka0xff@programmer.net> wrote in message
news:528ec373.0410181542.6c227525@posting.google.com...
Greets,
After searching until near exhaustion, I cannot find an electronics
vender that sells a general purpose wire wrap prototyping board. My
specs call for a Wirewrap Board having female connectors on top to
plug chips and such into with male feedthrough pin posts on the
underside (~13.0 mm) with a grounding plane. It needs to be a board
that one could apply a wire wraping tool against the pole points on
the underside with some wire to create custom design circuits. It is
similar to a bread board, but the main difference being that the wire
connections are made on the underside of the board. Most of my general
searchs have turned up tons of "PCB/PWB layout service" shops, but no
actual part. If you could point me in the general direction...
Thanks,
-Bob
Click to expand...
I think Augat used to make these, but not many people wirewrap any more.

Tam
 
Hi Bob,

Although I am not at all a fan of wire wrap and would not prototype with
it ever, I remember that this was the way it used to be done for boards:
You bought a normal experimenters board, ideally with a plane on top and
bottom, one for VCC and one for GND. Then sockets would be placed and
the corner pins (or whichever were supply and ground) were soldered to
the respective plane. That kind of held the socket in place. You could
also solder the other corners gently to the via for more rigidity,
making sure that no solder ever crept onto the wrap area of the posts.
That's why some people did this soldering from top.

The problem might be where to find these sockets with the long wrap
posts. They look like regular high quality machined IC sockets from the
top and have thick square posts at the bottom, about 3/4" or so in
length. In the early 80's you could buy them at any major distributor
but I haven't seen one in more than a decade. It may be necessary to
hunt for them on ebay or ask around this newsgroup. There are some folks
here who used to do a lot of wire wrap.

Regards, Joerg

http://www.analogconsultants.com
 
Hi Genome,

What's it like to be seriously dangerous and where can I get the datasheet?


Nothing seriously dangerous about that. Anybody should be able to do it
Click to expand...
with a 40106. A decent understanding of electronic design is required
though. The recipes are on page 3-390:

http://focus.ti.com/lit/ds/symlink/cd40106b.pdf

If that ain't enough, pick up a copy of AoE ;-)

Regards, Joerg

http://www.analogconsultants.com
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:m3Zcd.7344$6q2.3784@newssvr14.news.prodigy.com...
| Hi Genome,
|
| >What's it like to be seriously dangerous and where can I get the
datasheet?
| >
| >
| Nothing seriously dangerous about that. Anybody should be able to do it
| with a 40106. A decent understanding of electronic design is required
| though. The recipes are on page 3-390:
|
| http://focus.ti.com/lit/ds/symlink/cd40106b.pdf
|
| If that ain't enough, pick up a copy of AoE ;-)
|
| Regards, Joerg
|
| http://www.analogconsultants.com

OK, Thanks.

DNA
 
"Hassan" <hasan5012@yahoo.com> wrote in message
news:26acb996.0410181114.ce62dd6@posting.google.com...
Hello;
I want to design a switching power supply with:
Vin=24 Vdc and Vo=15V @ 7A
I am looking for a switcher IC something like LM2678 with integrated
controller and Power Mosfet. But LM2678 has a maximum current
limitation of 5A.
Does any body know an IC which I can use for this project? I mean
something with a controller and power Mosfet just in a package.

Thank you in advance
Hassan
Click to expand...
I use an IC that has the controller and a 1.5 amp drive transistor in it.
To get the extra amps, I add a power Mosfet to it. I drew a circuit using
the IC and a power Mosfet, to do what you want. You can see it at
http://www.fncwired.com/StepDnEx/
If you have any questions, please ask.
Brian
 
Hi,


[...]
I thought it would be impossible to find the actual capacitor, but the
leads
are fairly large near the header, and can be traced with the naked
eye. There
is indeed one sitting right before each header, and it is 47uf @ 25v.
Click to expand...
Rats. That makes thing harder.

[...]

And given that the capacitance is now known (47uf@25v=47uf@12v here
right?)
Click to expand...
It doesn't work like that I'm afraid. The '25V' on the capacitor means
the capacitor is rated for a maximum of 25V. It still has the valur of 47uf.

based on that how would one calculate the speed at which it discharges
with
a given resistor value @ 12v?
Click to expand...
This page may help -
http://www.play-hookey.com/dc_theory/rc_circuits.html - or just google
"rc discharge equation". Seeing there is a real capacitor there, the
calculations become a bit trickier. I'd crunch the numbers myself but i
don't have time right now.
And in this scenario, I guess we also need to know how fast the signal
is
pulsated?
Click to expand...
Yes.

As I'm assuming if the capacitor is not discharged fast
enough,
and the transistor has a certain threshold before it switches off, the
pulses coming off the transistor will be longer. Logic correct?
Click to expand...
Yes. One danger is that the transistor may operate in the linear region,
where it is neither fully on nor fully off. This means it will get much
hotter then if it was switched fully on or fully off. In a sealed
plastic box, this could cause problems.
What kind of box? Metal?


Plastic, 1" x 1" x 2".
Click to expand...
I'm not expert, but it sounds like that could be asking for trouble.
Maybe a cheap metal box would be the way to go?



4) hook up the circuit as follows




12V
|
|
|
FAN +

FAN -
|
|
|
|
|
120 ohms | Collector
___ |/
+12V from MB------|___|-----|
Base |
| Emitter
|
|
|

0V



Please bear with me for a second, and this might sound silly, but
shouldn’t the resistor connect with one end to the 12v MB and
the other end to 0V? (I think 0v is common ground in computers, that
is the case and every other component shares that ground.)
Click to expand...

It effectivly does!

There is a (small) vltage drop accross the Base-Emitter pins, but
otherwise its connected to 0V through the transistor.


Power Supply
| 12v+
|
|
|
|
|
Motherboard Header |/
12v+ ----------------------| NPN
| |> Transistor
.-. |
| | |
| | |
'-' |
Resistor | |
| |
| | +
| |
| .-.
| (FAN)
| '-'
| | -
| |
| |
___ ___
_ Ground _
| |



Would this schematic work? (Modulating (+) instead of ground?)
Click to expand...
Possibly, but its asking for trouble:

1) Too much base current may flow. The resistor in the first circuit
served to limit the bse current, but also to discharge the capacitor.

2) since you just want to use the NPN transistor as a switch, you are
better off placing the fan between 12V and the collector. I don't have
time to explain why right now, but google "common emitter" "emitter
follower" and "transistor switch".

I can give more details later if needed.

cheers,

Al

Thanks,
Mike
Click to expand...
 
Gentlemen,

thank you all for the comments, I learned a lot.

Sincerely,

Andrey




"Guy Macon" <http://www.guymacon.com> wrote in message
news:10n6phm6j849s57@news.supernews.com...
Andrey <a8421@intergate.bc.ca> says...

what would be wise recommendations for 100 ft long Serial cable.

should it be shielded or not? (from interference point of view it should.
But capacitance per length will go up. ??)

Is there any reason not to use heavier gauge wires?

What would be good cable for extended temperature range (-40C to +70C)
and
outsides (Sun, rain included)

What baud rate? TXD and RXD only, or handshaking?

Cat5 outdoor cable will handle the weather just fine and makes a fine
RS232 cable.

You can put the cable inside a PVC pipe or inside a high-quality
garden hose for protection against weather or physical damage.
Better yet would be a grounded metal pipe.

Interference won't be a big problem. Ground currents might be.
How sure are you that there isn't a voltage between the grounds
at the two ends?

What I would be concerned about most would be lighning strikes.
Do you have a plan to protect your equipment?

You really should consider putting optically Isolated RS-232 to
RS-422/485 Converters on both ends. Start here:
http://www.bb-elec.com/technical_library.asp
http://www.bb-elec.com/product_family.asp?familyid=14

--
Guy Macon <http://www.guymacon.com
Click to expand...
 
On Mon, 18 Oct 2004 20:06:40 -0400, Tam/WB2TT wrote:

"Bob Dang" <msucka0xff@programmer.net> wrote in message
news:528ec373.0410181542.6c227525@posting.google.com...
Greets,
After searching until near exhaustion, I cannot find an electronics
vender that sells a general purpose wire wrap prototyping board. My
specs call for a Wirewrap Board having female connectors on top to
plug chips and such into with male feedthrough pin posts on the
underside (~13.0 mm) with a grounding plane. It needs to be a board
that one could apply a wire wraping tool against the pole points on
the underside with some wire to create custom design circuits. It is
similar to a bread board, but the main difference being that the wire
connections are made on the underside of the board. Most of my general
searchs have turned up tons of "PCB/PWB layout service" shops, but no
actual part. If you could point me in the general direction...
Thanks,
-Bob

I think Augat used to make these, but not many people wirewrap any more.

AOL
Click to expand...
Me, Too!
</AOL>

But here's some sockets:
http://www.sourceresearch.com/frontline-interconnect/103.cfm

One of the places where I worked used so many of the boards you're
describing that they were in stock, i.e., go to the parts counter and
have them issue one. :) Augat was a big supplier, but as Tam/WB2TT wrote,
there's not a lot of market for wirewrap these days.

Good Luck!
Rich
 
Andrey <a8421@intergate.bc.ca> says...
Gentlemen,

thank you all for the comments, I learned a lot.
Click to expand...
But you didn't answer my question; do you have a plan to protect
your equipment from lighning strikes?
 
On Mon, 18 Oct 2004 15:58:32 -0700, Jim Thompson wrote:

On 18 Oct 2004 20:57:18 GMT, bobgardner@aol.comma (BobGardner) wrote:

They always told me 'there is no such thing as peak to peak voltage'. At one
instant, there is a positive peak voltage, and at some other instant, there is
a negative peak voltage, but the voltage is a function, and only has one value
at an instant in time. Now lets argue about whether the product of rms voltage
and rms current is rms power or average power.....

Track down, on a.b.s.e, the following post....

Peak-to-Peak Detector (S.E.D) - Peak-to-Peak-Detector.pdf
From: Jim Thompson Date: Tue, 21 Sep 2004 18:18:54 -0700 Size: 30.9k
Click to expand...
I get a feeling that bobgardner just wants to start a discussion over
whether the term "peak-to-peak" voltage even has meaning in the context of
a time-variant function.

In the interim, I've found the answer to the angels on a head of a pin
dilemma - an infinite number can dance on the head of a pin, since they're
imaginary and don't take up any space. ;-)

Cheers!
Rich
 
From: hybridyne2000@yahoo.com (Steve Sands)

Shamelessly cut and pasted from www.factcheck.org

At the final presidential debate, Bush said Kerry had passed only five
bills during his career, and Kerry said he had passed 56. Actually, we
found eleven measures authored by Kerry have been signed into law,
including a save-the-dolphins law, a law naming a federal building, a
law giving a posthumous award to Jackie Robinson last year, and laws
declaring "world population awareness weeks" in 1989 and 1991.

End----

Wow that's quite a career! If you subtract the completely meaningless
bills, Bush was right declaring 5 bills total for Kerry. That's one
bill every 4 years. One would have to conclude that the Senator's
positions were too extreme for 20 years having both party's in a
majority in congress. This man is not a concensus builder by any
means.

I disagree with your conclusion, I looked this up a while ago and found that
Click to expand...
Senators don't author many bills that get passed. I looked at several ranking
Republican Senators but can't remember their numbers, but do remember they were
not out of line with Kerry's, Maybe someone who has the time can do that
research. Kerry has worked to get a lot of bills passed, even though he did not
author that many. The gist of what I read is that he is a team player and not a
prima donna.

Still, even this 'smo;dering gun' seems made of soap compared to giving my
approval to a boob that looks us in the face and says that 75% of Al Qaida
Leaders have been captured or killed. That lie alone should be enough for all
of us to open the shitcan and throw him out with the trash.

Rocky


I looked this up a while ago and found that
 
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