magnetic field

On Tuesday, March 6, 2001 11:41:45 AM UTC-7, Randon Loeb wrote:

Trying to build a wireless mike for a guitar, not having much luck:
1. I have substituted MPS2222A tranistor for 2N2222. Is this ok for
this type of application? I was just guessing that the 2222 means they
are similar ;-)
2. How can you measure a coil's inductance? If you make the coil
yourself, can you be sure its "correct" somehow?
3. For testing, I have a 555 timer creating an a sound, that when
hooked up to a speaker sounds like a high pitched tone. at close range,
the tone is heard on FM radio, even without being hooked up to the
transmitter circuitry. Why is this? If the tone is audible, how are
radio waves in the FM band being produced? Is it ok to substitute such
a circuit for an electret mike, which will eventually be a feed from the
guitar or effects board?
4. How can I tell if I'm even getting RF waves out of my circuit? Can
an oscilliscope hooked up to the antenna tell me if i'm atleast getting
oscillation?

This is my first basic circuit that doesn't have led's or sound or
something to allow me troubleshoot and "see" what's happening. Any tips
on how to troubleshoot RF circuits like these?
Thanks

Using hearsay as a source of specific manufacture specifications information is full of misinformation. Spec. sheets are just a click away.

 

[Jasen Betts]

On 2013-04-02, abpccpba@gmail.com <abpccpba@gmail.com> wrote:

On Tuesday, March 6, 2001 11:41:45 AM UTC-7, Randon Loeb wrote:
Trying to build a wireless mike for a guitar, not having much luck:
1. I have substituted MPS2222A tranistor for 2N2222. Is this ok for
this type of application? I was just guessing that the 2222 means they
are similar ;-)

Using hearsay as a source of specific manufacture specifications information is full of misinformation. Spec. sheets are just a click away.

I reckon he's figured it out by now.


--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[Michael Black]

On Thu, 4 Apr 2013, Jasen Betts wrote:

On 2013-04-02, abpccpba@gmail.com <abpccpba@gmail.com> wrote:
On Tuesday, March 6, 2001 11:41:45 AM UTC-7, Randon Loeb wrote:
Trying to build a wireless mike for a guitar, not having much luck:
1. I have substituted MPS2222A tranistor for 2N2222. Is this ok for
this type of application? I was just guessing that the 2222 means they
are similar ;-)

Using hearsay as a source of specific manufacture specifications information is full of misinformation. Spec. sheets are just a click away.

I reckon he's figured it out by now.

And chances are good that if the guy who dug up this old post

looked further, they'd have seen a string of replies that actually helped
him. I can't be bothered checking google, but that's the norm every time
I've checked one of these time warp posts.

But yes, even if he hadn't got an answer back then,he likely would have
had the chance to figure it out after 12 years.

Michael

 

[Fred Abse]

On Sat, 06 Apr 2013 12:00:26 -0400, Michael Black wrote:

But yes, even if he hadn't got an answer back then,he likely would have
had the chance to figure it out after 12 years.

And people wonder why I don't want my posts archived by Google!

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[M.P. Android]

On Thu, 4 Jul 2013 05:38:42 -0700 (PDT), marketing@mediu.ws wrote:

197.160.120.96
Does anybody know why somebody would do this? Is it perhaps in a font

my reader doesn't know?
(The source IP is Egypt, which must be a chaotic place just now).

 

[Michael A. Terrell]

"M.P. Android" wrote:

On Thu, 4 Jul 2013 05:38:42 -0700 (PDT), marketing@mediu.ws wrote:

197.160.120.96
Does anybody know why somebody would do this? Is it perhaps in a font
my reader doesn't know?
(The source IP is Egypt, which must be a chaotic place just now).

Who cares? They are spamming the group.

 

[Jasen Betts]

On 2013-07-04, M.P Android <me@privacy.com> wrote:

On Thu, 4 Jul 2013 05:38:42 -0700 (PDT), marketing@mediu.ws wrote:

197.160.120.96
Does anybody know why somebody would do this? Is it perhaps in a font
my reader doesn't know?

Content-Type: text/plain; charset=us-ascii

I would say that it is a font your reader can't handle,

(The source IP is Egypt, which must be a chaotic place just now).

Google translate suggests it is an advert for a malaysian university,
the language, and the characters, are both arabic.

--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

Hello friend
This clock can be suitable for you

http://gxleds.en.alibaba.com/product/1218748851-219374502/Ganxin_GI6D_1R_1_inch_6_digit_remote_red_small_led_timer.html

 

On Sunday, October 6, 1996 3:00:00 AM UTC-4, John Morrow wrote:

Does anyone know where a person could get a collection of POPULAR
ELECTRONICS FACTCARDS? These FACTCARDS give typical applications for
IC's, display simple circuits, etc. Does Popular Electronics magazine
have a web site where one might get an online version of these fact
cards?

Thank You.

I have a partial collection of Hands on Electronics and Popular Electronics Fact Cards and will be willing to trade copies if you have any. Can also provide you with copy of individual cards but not all since there are about 300 of them.
I'm missing cards 1 through 9, 13 trough 24, 28 through 84, 88 through 93, 118 through 120, 226, 227, 228, and any additional ones after 270 if any.
Anyone interested may contact vcollazo@gmail.com

 

On Wednesday, October 16, 1996 12:00:00 PM UTC+5, Winfield Hill wrote:

Steve White, <stevew@hitl.washington.edu> said...

Michael Covington wrote:

Richard Steven Walz (rstevew@armory.com) wrote:

: Since I see Roland Hill posting here fairly often, and since I was
: once assured that one of the two had died, it seems logical to
: conclude that Horowitz is not teaching physics in the same way at ALL,
: actually. And doesn't he have another collaborator who wrote with him
: the latest adjunct labbook??

That'll be the Student Manual for The Art of Electronics, by Tom Hayes and
Paul Horowitz. See references in http://www.artofelectronics.com/

Er... It's Winfield Hill. And as far as I know, Paul Horowitz is very
much alive; ...

Well...Winfield Hill posts to this newsgroup rather regularly, so any
reports of his demise surely have been erronoeus. ...

I'm happy to report that even tho both Paul and I have passed the big 5 0 we
still feel like youngsters, and are firing with all our cylinders! Paul
still teaches Physics at Harvard, and sometimes the famous Physics 123
electronics course there as well, although there's now a small circle of
teachers who teach that one-semester course year around. Using AoE, natch.
The intense summer version is very popular among both Harvard students who
want to immerse themselves, and outsiders who don't have a lot of time to
spare from their other lives!
---------------------------------------------------------------------

So there is hope for a third edition, perhaps...

Still hoping for a third edition with some cool up to date stuff on
applying those nasty high bandwidth amplifiers that have recently
become so tempting to use, but tend to break into song at the
slightest reason to do so....Mr. Hill: do you take requests?

Requests for songs! No way! To your relief no doubt. Requests for new
topics or increases in coverage of certain items in the next edition?
You bet! Keep those cards and letters coming folks!

Now about your comments on the new high-speed amplifiers. My advice is to
use them - go for it! Unlike the high-speed amplifiers of old, the new
breeds are remarkably stable and easy to apply. They don't often break into
song for me! Perhaps the custom ground-plane breadboard I designed helps, and
closely-placed supply-bypass caps for every other opamp help too. Also, I
try to follow the rules and advice on the data sheets, such as no feedback
capacitors with the current-feedback configuration, etc.

We'll have lots to say on this subject the next time around (although the
present 2nd ed. does include 22 high-speed opamps in our selection table on
page 878, including 7 current-feedback models). And, I'll present a whole
new way of looking at these new amplifiers that'll knock your socks off!

So, sure there'll be another Horowitz and Hill AoE edition someday. As we've
stated before. Like the last one, we'll be removing many chapters, adding
lots of others and in general performing a massive rebirth, worthy of the
high expectations. And folks! that takes time and hard work, lots of it.
Meanwhile, Paul and I have other lives too! He's got to be a Harvard prof,
teaching the world, and I've got to boldly explore new and exotic electronic
designs! So the official line is - years and years into the future.
Certainly nobody should deprive themselves of a copy while waiting! Anyway,
as I said, lots of good stuff will be displaced by new things the next time
around; you'll want copies of both!

Meanwhile, as Steve Wiseman and others have pointed out, there are lots of
other interesting application notes and advanced texts out there, just
waiting for hungry readers who've already devoured AoE!

Everybody should have a copy of Jim Williams and Bob Peases's inspirational
books, and don't miss Jerald Graeme's "Photodiode Amplifiers" (McGraw-Hill
ISBN 0-07-024247-X). Finally, I recommend that you be sure to get a copy of
"High-Speed Digital Design, a Handbook of Black Magic" by Johnson and Graham,
PTR Prentice Hall, 1993, before it goes out of print.

--
Winfield Hill hill@rowland.org
The Rowland Institute for Science _/_/_/ _/_/_/_/
100 Edwin Land Blvd. _/ _/ _/_/ _/
Cambridge, MA USA 02142-1297 _/_/_/_/ _/ _/ _/_/_/
_/ _/ _/ _/ _/
http://www.artofelectronics.com/ _/ _/ _/_/ _/_/_/_/

sir please send me electronic principle by albert malvino 6th eddition or 7th

 

[Shaun]

wrote in message
news:b740eae5-b3ec-4cb5-ba68-58843c8e57bb@googlegroups.com...

On Wednesday, October 16, 1996 12:00:00 PM UTC+5, Winfield Hill wrote:

Steve White, <stevew@hitl.washington.edu> said...

Michael Covington wrote:

Richard Steven Walz (rstevew@armory.com) wrote:

: Since I see Roland Hill posting here fairly often, and since I was
: once assured that one of the two had died, it seems logical to
: conclude that Horowitz is not teaching physics in the same way at
ALL,
: actually. And doesn't he have another collaborator who wrote with him
: the latest adjunct labbook??

That'll be the Student Manual for The Art of Electronics, by Tom Hayes and
Paul Horowitz. See references in http://www.artofelectronics.com/

Er... It's Winfield Hill. And as far as I know, Paul Horowitz is very
much alive; ...

Well...Winfield Hill posts to this newsgroup rather regularly, so any
reports of his demise surely have been erronoeus. ...

I'm happy to report that even tho both Paul and I have passed the big 5 0
we
still feel like youngsters, and are firing with all our cylinders! Paul
still teaches Physics at Harvard, and sometimes the famous Physics 123
electronics course there as well, although there's now a small circle of
teachers who teach that one-semester course year around. Using AoE,
natch.
The intense summer version is very popular among both Harvard students who
want to immerse themselves, and outsiders who don't have a lot of time to
spare from their other lives!
---------------------------------------------------------------------

So there is hope for a third edition, perhaps...

Still hoping for a third edition with some cool up to date stuff on
applying those nasty high bandwidth amplifiers that have recently
become so tempting to use, but tend to break into song at the
slightest reason to do so....Mr. Hill: do you take requests?

Requests for songs! No way! To your relief no doubt. Requests for new
topics or increases in coverage of certain items in the next edition?
You bet! Keep those cards and letters coming folks!

Now about your comments on the new high-speed amplifiers. My advice is to
use them - go for it! Unlike the high-speed amplifiers of old, the new
breeds are remarkably stable and easy to apply. They don't often break
into
song for me! Perhaps the custom ground-plane breadboard I designed helps,
and
closely-placed supply-bypass caps for every other opamp help too. Also, I
try to follow the rules and advice on the data sheets, such as no feedback
capacitors with the current-feedback configuration, etc.

We'll have lots to say on this subject the next time around (although the
present 2nd ed. does include 22 high-speed opamps in our selection table
on
page 878, including 7 current-feedback models). And, I'll present a whole
new way of looking at these new amplifiers that'll knock your socks off!

So, sure there'll be another Horowitz and Hill AoE edition someday. As
we've
stated before. Like the last one, we'll be removing many chapters, adding
lots of others and in general performing a massive rebirth, worthy of the
high expectations. And folks! that takes time and hard work, lots of it.
Meanwhile, Paul and I have other lives too! He's got to be a Harvard
prof,
teaching the world, and I've got to boldly explore new and exotic
electronic
designs! So the official line is - years and years into the future.
Certainly nobody should deprive themselves of a copy while waiting!
Anyway,
as I said, lots of good stuff will be displaced by new things the next
time
around; you'll want copies of both!

Meanwhile, as Steve Wiseman and others have pointed out, there are lots of
other interesting application notes and advanced texts out there, just
waiting for hungry readers who've already devoured AoE!

Everybody should have a copy of Jim Williams and Bob Peases's
inspirational
books, and don't miss Jerald Graeme's "Photodiode Amplifiers" (McGraw-Hill
ISBN 0-07-024247-X). Finally, I recommend that you be sure to get a copy
of
"High-Speed Digital Design, a Handbook of Black Magic" by Johnson and
Graham,
PTR Prentice Hall, 1993, before it goes out of print.

--
Winfield Hill hill@rowland.org
The Rowland Institute for Science _/_/_/ _/_/_/_/
100 Edwin Land Blvd. _/ _/ _/_/ _/
Cambridge, MA USA 02142-1297 _/_/_/_/ _/ _/ _/_/_/
_/ _/ _/ _/ _/
http://www.artofelectronics.com/ _/ _/ _/_/ _/_/_/_/

sir please send me electronic principle by albert malvino 6th eddition or
7th

Malvino is a good author, his books are easy to understand. I'm sure you
could download a basic electronics book off the internet.

Shaun

 

Hi;

I'm Benjou Espiloy from Philippines and now I'm currently enrolled at CIE home study program and taking up Broadcast engineering.. it is good for you cause you have a background in electronics just like me I have my previous experience on satellite antenna installation and maintenance in actualization but with the help of this lesson from CIE from basic up to major topic on my course I learn a lot because every topic that you encounter on this course were very helpful to be come a success in electronic field. topics and modules are pretty nice and helpful especially to those people wants to continue their engineering course.

 

[Gunner Asch]

On Mon, 13 Jan 2014 07:06:29 -0600, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:

David Billington <djb@djbillington.freeserve.co.uk> fired this volley in
news:52d3e44d$0$1398$5b6aafb4@news.zen.co.uk:

What's the benefit of a low voltage contactor and safety circuit? I have
various equipment with safety circuits and they use either the 230V or
415V supply for the contactor and safety circuit.

It's simple, cheap, and easy to rig remote switching and sensors for things
like safety guards. It requires only bell wire and some thoughtful
routing, rather than running live power everywhere a switch is required.

LLoyd

Big gold star!!


__
"Anyone who thinks Obama is doing a good job
is either stupid or a perpetual societal leech"

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

 

On Sunday, February 14, 1999 3:00:00 AM UTC-5, EW_Chua wrote:

BGA Automatic Pick and Place System.

We are in urgent need for the above system.
It is used to sort BGA packages from film frames to an output carrier, The
machine must includes an automatic cassette feed system, rotating pick head,
and pattern recognition alignment on the input and output stations.
We are willing to buy new or used.

For more details or submission of proposal, please contact :

KH Lee
Tel:65-7511128 / Fax:65-7555387
Email: kahheng@stats.st.com.sg
EW Chua
Tel:65-7511126 / Fax:65-7555387
Email: chuaew@stats.st.com.sg

Hi, not sure if this post is very old. I seen bunch of auto pick bga machine now a day. I have Bauer RW Sv550 and is very happy with that machine. If you are interested, why not check out Bauer RW SV550?

 

[Jeff Thies]

On 1/26/2014 11:35 AM, Fred Abse wrote:

On Sun, 26 Jan 2014 08:13:56 -0500, Jim Wilkins wrote:

"DoN. Nichols" <BPdnicholsBP@d-and-d.com> wrote in message
news:slrnle97cu.5kc.BPdnicholsBP@Katana.d-and-d.com...
On 2014-01-25, Jim Wilkins <muratlanne@gmail.com> wrote:

Why do you need two fuses for a single-phase motor?

In the UK, you don't, because 240 VAC comes with one side grounded.
However, in the USA, 240 VAC is normally supplied with a grounded center
tap, so if you have only one fuse -- or have two but only one blows, you
still have 120 VAC live in the motor's housing, and
potentially available for contact and personal zapping.


I assumed it was wired with a 20A double-pole breaker at the panel
protecting from shorts and a smaller fuse sized (how?) to blow before the
motor burned out.


Panel breakers are there to protect the upstream wiring from excessive
load current, not to protect the load.

Matching the I-squared-t of a breaker, or fuse, to startup and running
conditions of a motor is not trivial. Motors are subject to starting
inrush currents sometimes tens of times the rated full-load current. Be
guided by the data published by reputable manufacturers. There's plenty of
it.

Most motors are tough old buzzards. Why the op needs more protection is
unknown, I would think some kind of thermal or time delay overload is
sufficient which may already be in the motor.

Jeff

 

[Michael A. Terrell]

Jeff Thies wrote:

On 1/26/2014 11:35 AM, Fred Abse wrote:
On Sun, 26 Jan 2014 08:13:56 -0500, Jim Wilkins wrote:

"DoN. Nichols" <BPdnicholsBP@d-and-d.com> wrote in message
news:slrnle97cu.5kc.BPdnicholsBP@Katana.d-and-d.com...
On 2014-01-25, Jim Wilkins <muratlanne@gmail.com> wrote:

Why do you need two fuses for a single-phase motor?

In the UK, you don't, because 240 VAC comes with one side grounded.
However, in the USA, 240 VAC is normally supplied with a grounded center
tap, so if you have only one fuse -- or have two but only one blows, you
still have 120 VAC live in the motor's housing, and
potentially available for contact and personal zapping.


I assumed it was wired with a 20A double-pole breaker at the panel
protecting from shorts and a smaller fuse sized (how?) to blow before the
motor burned out.


Panel breakers are there to protect the upstream wiring from excessive
load current, not to protect the load.

Matching the I-squared-t of a breaker, or fuse, to startup and running
conditions of a motor is not trivial. Motors are subject to starting
inrush currents sometimes tens of times the rated full-load current. Be
guided by the data published by reputable manufacturers. There's plenty of
it.

Most motors are tough old buzzards. Why the op needs more protection is
unknown, I would think some kind of thermal or time delay overload is
sufficient which may already be in the motor.

I got this in an email from someone who wasn't able to post directly:

<http://www.ab.com/en/epub/catalogs/12768/229240/229248/10521726/10551021/10551660/>

Obviously, I can't post to the newsgroup.

Jeff Angus

 

[Peter Bennett]

On Sat, 22 Mar 2014 11:09:39 -0700, DaveC <invalid@invalid.net> wrote:

Looking for the manufacturer and (praying) the series of this connector:

http://oi57.tinypic.com/w7luea.jpg

http://oi57.tinypic.com/2hylbub.jpg

It is not proprietary‹it was used to connect 2 old pieces of equipment much
older than this connector. 

Ideas?

Thanks.

Cinch Jones Plug - available from Mouser, made by www.cinch.com

--
Peter Bennett, VE7CEI Vancouver BC
peterbb (at) telus.net
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

On Sunday, February 14, 1999 3:00:00 AM UTC-5, EW_Chua wrote:

BGA Automatic Pick and Place System.

We are in urgent need for the above system.
It is used to sort BGA packages from film frames to an output carrier, The
machine must includes an automatic cassette feed system, rotating pick head,
and pattern recognition alignment on the input and output stations.
We are willing to buy new or used.

For more details or submission of proposal, please contact :

KH Lee
Tel:65-7511128 / Fax:65-7555387
Email: kahheng@stats.st.com.sg
EW Chua
Tel:65-7511126 / Fax:65-7555387
Email: chuaew@stats.st.com.sg

Contact me and I'll get it for you.
Visit www.advancedreworks.com

 

[Geo]

On Mon, 21 Apr 2014 21:57:43 -0700 (PDT), drichiez@hotmail.com wrote:

On Sunday, February 14, 1999 3:00:00 AM UTC-5, EW_Chua wrote:
BGA Automatic Pick and Place System.

We are in urgent need for the above system.

Contact me and I'll get it for you.
Visit some spammer's website

It was URGENT in 1999 you twat!

 

[conundrum]

On Wednesday, May 28, 2014 9:54:44 PM UTC+1, Gary Walters wrote:

Crest model 4G-250-3, early 90's vintage.



Part numbers have been sanded off all ICs.



It would be great to find a schematic...



Thanks.

High frequency op amp most likely.

IIRC the ultrasonic foggers use 1.67 MHz and the smaller ones use around 30-40 kHz (thanks Sam!) but 67kHz is becoming popular as it is less likely to interfere with other devices and is more effective for cleaning.