M
Mike Berger
Guest
If they're National, they're probably 2N numbers.
sreenath wrote:
sreenath wrote:
R
Reinhard Zwirner
Guest
sreenath schrieb:
specifications for one single customer. In common those transistors have
uncommon type numbers.
On the other hand, there may be a solution for your problem. When you
look into an old NS transistor data book, you won't find detailed data
for type numbers - you'll find them for processes! Of course there is a
table with some 'coarse' data for National's transistor types (like
2N2222),
but details can be found under "process 19". Perhaps the colour marking
corresponds to the number of the process.
HTH
Reinhard
There is a reason: if those transistors were produced with some special
specifications for one single customer. In common those transistors have
uncommon type numbers.
On the other hand, there may be a solution for your problem. When you
look into an old NS transistor data book, you won't find detailed data
for type numbers - you'll find them for processes! Of course there is a
table with some 'coarse' data for National's transistor types (like
2N2222),
but details can be found under "process 19". Perhaps the colour marking
corresponds to the number of the process.
HTH
Reinhard
R
Rich Webb
Guest
On Fri, 4 Nov 2005 18:30:55 -0800, "Scott Kelley" <scottk@iccom.com>
wrote:
waves that are indistinguishable from sine waves are OK), so take the
single shot (not repetitive) sample rate (say 40 Msps for a popular
model) and divide the Nyquist freq by five: 4 MHz. That's certainly OK
for audio and quite a bit more. Just know what it is you're getting.
Digital displays are fairly cheap and easy (as compared to the monster
CRTs and supporting electronics of a generation ago) so consider that on
a real portable scope you're paying for the sampling and the signal
processing, not so much the user interface -- and you'd pay just about
as much for an equivalent capability if the GUI was offloaded to a PC.
If you need to be "battery portable" the price goes up a bit but if you
can get along with a power cord, Tek and HP both have very capable
digital scopes in the $1200 - $2K range that are small enough to take
along with you. If you really need battery portable, add Fluke's
ScopeMeters to the mix along with the other two.
--
Rich Webb Norfolk, VA
wrote:
Figure you'll want to see at least the fifth harmonic (unless square
waves that are indistinguishable from sine waves are OK), so take the
single shot (not repetitive) sample rate (say 40 Msps for a popular
model) and divide the Nyquist freq by five: 4 MHz. That's certainly OK
for audio and quite a bit more. Just know what it is you're getting.
Digital displays are fairly cheap and easy (as compared to the monster
CRTs and supporting electronics of a generation ago) so consider that on
a real portable scope you're paying for the sampling and the signal
processing, not so much the user interface -- and you'd pay just about
as much for an equivalent capability if the GUI was offloaded to a PC.
If you need to be "battery portable" the price goes up a bit but if you
can get along with a power cord, Tek and HP both have very capable
digital scopes in the $1200 - $2K range that are small enough to take
along with you. If you really need battery portable, add Fluke's
ScopeMeters to the mix along with the other two.
--
Rich Webb Norfolk, VA
Guest
http://slashdot.org/article.pl?sid=05/11/04/2316238&threshold=5#13955473
..
..
http://www.google.com/search?q=Distance-Learning+John-Bear
A
Art
Guest
Definately stay away from the Tenma Brand supplied by MCM Electronis.
Totally useless unless you like the storage DMM features or work only with
audio signals, most of the time they do not sync even at vertical
frequencies and are useless at horiz frequencies, exp in HD monitors or RF
circuitry.
"Rich Webb" <bbew.ar@mapson.nozirev.ten> wrote in message
news:rg8om15v0d045ia63qc83llvktsn9jren9@4ax.com...
Totally useless unless you like the storage DMM features or work only with
audio signals, most of the time they do not sync even at vertical
frequencies and are useless at horiz frequencies, exp in HD monitors or RF
circuitry.
"Rich Webb" <bbew.ar@mapson.nozirev.ten> wrote in message
news:rg8om15v0d045ia63qc83llvktsn9jren9@4ax.com...
T
The Alien
Guest
Paybacks are hell! Go get 'em "Jim"!!! hehehe!
On Fri, 24 Oct 2003 12:46:35 -0700, Jim Thompson
<invalid@invalid.invalid> scratched with their pencil:
------------------------------------------------
Autobot This Spammers!
<A HREF="mailto
ostmaster@[127.0.0.1]"></A>
mailtoostmaster@127.0.0.1
(to reply to actual address, dispense the dots before
and after sirname.
On Fri, 24 Oct 2003 12:46:35 -0700, Jim Thompson
<invalid@invalid.invalid> scratched with their pencil:
------------------------------------------------
Autobot This Spammers!
<A HREF="mailto
ostmaster@[127.0.0.1]"></A>mailto
ostmaster@127.0.0.1(to reply to actual address, dispense the dots before
and after sirname.
S
slodgey
Guest
I have been using a Fluke Scopemeter 97 for about 8yrs. They are
excellent but expensive. I think the newer models are even better. The
one I have has a link for the PC but I think it costs me extra.
excellent but expensive. I think the newer models are even better. The
one I have has a link for the PC but I think it costs me extra.
Guest
There are some very nice devices like this on the market, however, the
speed of most of these limits their use to audio work for the most
part. I really wouldn't want to use any that I had access to for
digital work. Most of these are produced by small garage firms, and
usually advertise for sales in publications like 'Nuts & Volts'. These
of of limited use, but in certain situation they are 'the handiman's
friend', just like Duct Tape.
A common feature on many of these is the ability to display in either
the time domain or the frequency domain (Fourier Transform). This is a
surprisingly useful feature in audio and analog communications work,
particularly when working in the field and you have to carry and entire
lab in your suitcase!
Sadly I don't own one, so when I travel to the field to do work for the
FAA or some other organization, the only off-the-shelf instrumentation
I carry with me is a Tek pocket oscilloscope (owned by my employer), a
laptop and prom burner (for implementing embedded code changes in the
field), an inexpensive Wavetek DMM, a small set of handtools, a small
soldering iron, and a few home made kludges that often prove useful in
my field of work.
You'd be amazed at how useful a simple 9-volt battery with clip on test
leads soldered to it can be for tracing and polarizing comm lines,
forcing logic states (with a current limiting resistor) and a myriad of
other uses.
Kindest regards, Harry C.
..
speed of most of these limits their use to audio work for the most
part. I really wouldn't want to use any that I had access to for
digital work. Most of these are produced by small garage firms, and
usually advertise for sales in publications like 'Nuts & Volts'. These
of of limited use, but in certain situation they are 'the handiman's
friend', just like Duct Tape.
A common feature on many of these is the ability to display in either
the time domain or the frequency domain (Fourier Transform). This is a
surprisingly useful feature in audio and analog communications work,
particularly when working in the field and you have to carry and entire
lab in your suitcase!
Sadly I don't own one, so when I travel to the field to do work for the
FAA or some other organization, the only off-the-shelf instrumentation
I carry with me is a Tek pocket oscilloscope (owned by my employer), a
laptop and prom burner (for implementing embedded code changes in the
field), an inexpensive Wavetek DMM, a small set of handtools, a small
soldering iron, and a few home made kludges that often prove useful in
my field of work.
You'd be amazed at how useful a simple 9-volt battery with clip on test
leads soldered to it can be for tracing and polarizing comm lines,
forcing logic states (with a current limiting resistor) and a myriad of
other uses.
Kindest regards, Harry C.
..
Guest
jay_beveridge@hotmail.com wrote:
made 12v drill pack.
charge, but it might be higher than this.
There is a better way, which is to run your 6v devices off half of the
batteries, then off the other half. The (trivial) downside is you need
to charge them as 2 packs of 6v, ie your charger to battery connection
will have 3 wires not 2. This way you'll get twice as long run times on
6v loads, and ditto with <6v.
If you just need 6v and 12v out, no regulator is then required. For 9v
run it off 12v via 3x diodes in series, for 5v off 6v via one diode.
NT
good idea
Cordless drills usually use sub-c cells, I'd go with those - or a ready
made 12v drill pack.
voltage regulator.
cars run ITRO 14.4v with engine on. I forget what V NiCds need to
charge, but it might be higher than this.
yep
yep.
There is a better way, which is to run your 6v devices off half of the
batteries, then off the other half. The (trivial) downside is you need
to charge them as 2 packs of 6v, ie your charger to battery connection
will have 3 wires not 2. This way you'll get twice as long run times on
6v loads, and ditto with <6v.
If you just need 6v and 12v out, no regulator is then required. For 9v
run it off 12v via 3x diodes in series, for 5v off 6v via one diode.
NT
C
CWatters
Guest
<meow2222@care2.com> wrote in message
news:1131710891.557739.159230@g43g2000cwa.googlegroups.com...
be enough headroom to make a decent constant current source if you only have
14.4V
news:1131710891.557739.159230@g43g2000cwa.googlegroups.com...
They need a constant current source not a constant voltage. There might not
be enough headroom to make a decent constant current source if you only have
14.4V
J
JosephKK
Guest
Spehro Pefhany wrote:
start) capabilities vary with price.
--
JosephKK
quality (harmonics, frequency accuracy, etc.,) and reactive load (motor
start) capabilities vary with price.
--
JosephKK
J
JosephKK
Guest
Winfield Hill wrote:
--
JosephKK
sine waves, including fractional horsepower to 250 horsepower.
--
JosephKK
J
JosephKK
Guest
Jon Elson wrote:
--
JosephKK
and report back to us.
--
JosephKK
S
Spehro Pefhany
Guest
On Fri, 11 Nov 2005 21:50:27 GMT, the renowned JosephKK
<joseph2k@lanset.com> wrote:
http://www.phase-a-matic.com/PDF/SPL-2005-C.pdf
Note that it only yields 0.5 to 0.67 of rated horsepower.
Here, from another company, is an explanation of what a static phase
converter is:
http://www.phaseconverter.com/what-is-static.html
And another one:
http://www.boost-energy.com/boost/phaseconverters_ap.asp
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
<joseph2k@lanset.com> wrote:
?? Those are usually called VFDs.
Here is a familiar example of a static phase converter:
http://www.phase-a-matic.com/PDF/SPL-2005-C.pdf
Note that it only yields 0.5 to 0.67 of rated horsepower.
Here, from another company, is an explanation of what a static phase
converter is:
http://www.phaseconverter.com/what-is-static.html
And another one:
http://www.boost-energy.com/boost/phaseconverters_ap.asp
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
J
JosephKK
Guest
Don Lancaster wrote:
phase is still less than 50 A, no worse than starting every element of an
electric stove and oven at the same time. Of course motor start surges are
an issue, but successful VFD vendors have taken this in to account.
--
JosephKK
PFC switchers for 1 kW to 10 kW are better still. 10 HP at 240 single
phase is still less than 50 A, no worse than starting every element of an
electric stove and oven at the same time. Of course motor start surges are
an issue, but successful VFD vendors have taken this in to account.
--
JosephKK
J
JosephKK
Guest
awright wrote:
at the manufacturer, the press , and all your friends, associates,
neighbors, and acquaintances. Selling short lived pieces of crap must be
punished.
--
JosephKK
the washer is a piece of crap. do not buy that brand for years and scream
at the manufacturer, the press , and all your friends, associates,
neighbors, and acquaintances. Selling short lived pieces of crap must be
punished.
--
JosephKK
Guest
CWatters wrote:
Doesnt necessarily have to be constant, as long as its limited. Of
course they cant be charged from a V source like lead acids.
If the NiCds needed 13v minimum, one could probably work with that,
using eg a low dropout current limiting regulator. But I dont know what
V is needed.
There is one workaround if theres not enough headroom: charge the pack
as 2x 6v packs. This means breaking the connection halfway along the
battery chain - eg with a piece of card - and current limiting the
charge for each 6v section.
NT
Doesnt necessarily have to be constant, as long as its limited. Of
course they cant be charged from a V source like lead acids.
If the NiCds needed 13v minimum, one could probably work with that,
using eg a low dropout current limiting regulator. But I dont know what
V is needed.
There is one workaround if theres not enough headroom: charge the pack
as 2x 6v packs. This means breaking the connection halfway along the
battery chain - eg with a piece of card - and current limiting the
charge for each 6v section.
NT
C
CWatters
Guest
<meow2222@care2.com> wrote in message
news:1131750479.692905.240910@g47g2000cwa.googlegroups.com...
cheap.
news:1131750479.692905.240910@g47g2000cwa.googlegroups.com...
Yes that would be the best way to go. You can buy chargers for that really
cheap.
P
Paul Perry
Guest
If you record audio from a TV & look at the envelope of the
signal, you will see that the peak signal levels during the program
is the same as durin the commercials. But, during the commercials,
the signal is heavily compressed, to put more average audio power in.
So what I think may be happening here, is the TV audio is being
compressed ALL the time (makes no difference to the commercials, but
brings up quiet passages in the normal priogram material). this
enables the volume level setting to be backed off & the
commercials no longer appear relatively loud.
I feel sorry for anyone who owns a TV though.
signal, you will see that the peak signal levels during the program
is the same as durin the commercials. But, during the commercials,
the signal is heavily compressed, to put more average audio power in.
So what I think may be happening here, is the TV audio is being
compressed ALL the time (makes no difference to the commercials, but
brings up quiet passages in the normal priogram material). this
enables the volume level setting to be backed off & the
commercials no longer appear relatively loud.
I feel sorry for anyone who owns a TV though.
P
Paul Perry
Guest
I notice that some universities put material on the web (sometimes at
least as comprehensive as the average text). That way, it can be
updated whenever the need arises. I was a secondhand book dealer for
many years & you can tell that most books were very lightly read.
The vast majority of texts are completely unnecessary, & the stuff
that changes from year to year could easily be coveredby a few web
references today.
As for 'timeless' stuff like calculus.. each year the books are
fatter, more colorful, and more dumbed down, on the average.
I'm not sure where the pressure for "me too" average texts comes from,
probably more ego than greed.
When it comes to a basic practical analog text, Horowitz & Hill
"The Art of Electronics" will do me fine. I can fill the gaps from
the web, no problem.
least as comprehensive as the average text). That way, it can be
updated whenever the need arises. I was a secondhand book dealer for
many years & you can tell that most books were very lightly read.
The vast majority of texts are completely unnecessary, & the stuff
that changes from year to year could easily be coveredby a few web
references today.
As for 'timeless' stuff like calculus.. each year the books are
fatter, more colorful, and more dumbed down, on the average.
I'm not sure where the pressure for "me too" average texts comes from,
probably more ego than greed.
When it comes to a basic practical analog text, Horowitz & Hill
"The Art of Electronics" will do me fine. I can fill the gaps from
the web, no problem.