MessageView 421F schematic

[Vidar Lřkken]

Arny Krueger wrote:

According to several references, GFCI designed for personnel
protection will trip when leakage current exceeds 5
milliamps.

Yep, which is _far_ from 70ľA. But in Norway, the norm is 30mA. However,
Norway has a IT-net, not a TN-net. (Or was it TT? Never remember the
difference )


--
MVH,
Vidar

www.bitsex.net

 

[Steve Urbach]

On Mon, 13 Jun 2005 14:54:01 +0300, "Dimitrios Tzortzakakis"
<dimtzort@otenet.gr> wrote:

If that happens, then why does not my GFCI breaker trip?

--
1) the leakage current is below the GFIC trip threshold (this is

likely, as the threshold would be set to prevent 'nuisance trips)
2) the GFIC breaker is defective or improperly installed.
3) You are not plugged into the circuit protected by the GFIC breaker
, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org

 

[Arny Krueger]

Vidar Lřkken wrote:

Arny Krueger wrote:

According to several references, GFCI designed for
personnel
protection will trip when leakage current exceeds 5
milliamps.


Yep, which is _far_ from 70ľA. But in Norway, the norm is
30mA.

In the US - we consider 30 ma to be the limit for protecting
equipment. The threshold for protecting personel is 5 ma.

 

[Vidar Lřkken]

Arny Krueger wrote:

Yep, which is _far_ from 70ľA. But in Norway, the norm is

30mA.

In the US - we consider 30 ma to be the limit for protecting
equipment. The threshold for protecting personel is 5 ma.

Yep, which relates back to that in a IT-net you have insulation between
the midpoint in xmfr and gnd, that also limits the current, while in the
US you have a TN net where gnd is connected straight to the mid-point.
Don't ask me to explain the differences, I only know that the norwegian
system is considdered safer, and there's two countries that is using it.
Norway and Peru or something like that.
So we have 2 wires, with a potential to each other of 220V, both being
"hot" relative to gnd.

Perphaps someone else in here can explain the difference between a IT
and a TN/TT net?

--
MVH,
Vidar

www.bitsex.net

 

[Arny Krueger]

Vidar Lřkken wrote:

Arny Krueger wrote:

Yep, which is _far_ from 70ľA. But in Norway, the norm
is

30mA.

In the US - we consider 30 ma to be the limit for
protecting
equipment. The threshold for protecting personel is 5 ma.



Yep, which relates back to that in a IT-net you have
insulation
between the midpoint in xmfr and gnd, that also limits the
current,
while in the US you have a TN net where gnd is connected
straight to
the mid-point.

See reference, below.

Don't ask me to explain the differences, I only know
that the norwegian system is considdered safer, and
there's two
countries that is using it. Norway and Peru or something
like that.
So we have 2 wires, with a potential to each other of
220V, both being
"hot" relative to gnd.

Perphaps someone else in here can explain the difference
between a IT
and a TN/TT net?

http://www.mikeholt.com/documents/mojofiles/electricalearthingworldwide.pdf

pp 7-8

 

[Vidar Lřkken]

Arny Krueger wrote:

http://www.mikeholt.com/documents/mojofiles/electricalearthingworldwide.pdf

Thanks a lot That was a quite informative pdf, actually I should've
remembered my electrical installations book was 2 meter from me...
Thought I'd sold that book after last year, but anyway, that PDF
described it better than the book!

pp 7-8

I had a peek at the rest...


--
MVH,
Vidar

www.bitsex.net

 

[Kitchen Man]

On Sun, 12 Jun 2005 21:33:53 -0500, Jim Adney <jadney@vwtype3.org>
wrote:

Sure, it's 60V as seen on a 10 MOhm meter, but the source impedance is
on the order of a MegOhm. That's never going to provide enough current
to be dangerous. Of course that assumes that all his components remain
in good condition. If something actually fails, then you're right and
he is without a safety ground.

Right on both points. It's that pesky second point that bothers me.
In addition, that small but probably continuous current could be
damaging to sensitive components; remember we're dealing with a
computer and a cable modem here, lots of low voltage, low current,
high speed "stuff" that could be damaged by strong transients.

An interesting but flawed solution is to connect the power strip
"ground" to the shield of the modem. That would give the strip a
return reference, but one fraught with difficulty on a number of
levels - power currents injected into an RF shield being the most
conspicuous. I don't like it. I'd get an electrician.

--
Al Brennan

"If you only knew the magnificence of the 3, 6 and 9,
then you would have a key to the universe." Nicola Tesla

 

[Dimitrios Tzortzakakis]

--
Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr
? "Steve Urbach" <dragonsclaw@NOTmindspring.com> ?????? ??? ??????
news:3m8ra11l2gg8j42d0vdnlcboime7mgi63t@4ax.com...

On Mon, 13 Jun 2005 14:54:01 +0300, "Dimitrios Tzortzakakis"
dimtzort@otenet.gr> wrote:

If that happens, then why does not my GFCI breaker trip?

--
1) the leakage current is below the GFIC trip threshold (this is
likely, as the threshold would be set to prevent 'nuisance trips)
The threshold in europe is always 30 mA.
2) the GFIC breaker is defective or improperly installed.
It's a new Siemens GFCI breaker I installed myself, and I hope I can install

one correctly.

3) You are not plugged into the circuit protected by the GFIC breaker
, _
The breaker protects my whole house.
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7
Have you helped? http://www.grid.org

 

[Steve Urbach]

On Tue, 14 Jun 2005 14:55:33 +0300, "Dimitrios Tzortzakakis"
<dimtzort@otenet.gr> wrote:

The breaker protects my whole house.
Ah!

the difference between international systems.
The US residential mainly requires only certain Branch circuits to be
GFIC (and now ARC fault) protected. Newer 'Industrial' systems have
the "whole" service panel version.

, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org

 

[John Miles]

In article <1118799288.293607.234780@o13g2000cwo.googlegroups.com>,
bobd426@yahoo.com says...

Thanks in advance for any help. This is a heck of a puzzle for me.

Manuals seem scarce for that one! Both my usual sources (Consolidated
Surplus and Manuals Plus) bombed out.

It shouldn't be hard to figure out what's up, though. If you poke
around on the output fitting assembly with a scope or voltmeter while
varying the amplitude, you should find the terminal where the rectified
sample of the RF voltage is extracted. It will probably be less than a
couple volts at full-scale output. See if that voltage is still present
when the unit acts up. If not, the output sampler is your problem.

If so, find the mixer/modulator assembly, or whatever Wiltron calls it.
I believe they used HP PIN modulators in at least some of these plugins.
It will have RF in/out ports and a third control port where the ALC
circuit applies a current to control the output amplitude. Measure the
current and/or voltage here and see what happens to it when the symptom
occurs. Depending on what you see, that may give you some ideas where
to look. You may have to open the loop by disconnecting the output
sampler connection and applying a constant voltage to tell exactly where
the fault is occurring.

A hair dryer/can of Freeze-Mist to the ALC board is the next, and
hopefully final, step.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

 

[lon]

Get an outlet tester. They plug into the outlet and let you know if it is
wired correctly.

I believe you will find that you have an outlet with the neutral and hot
reversed.

How is your internet connection? In my experience this can cause wicked
packet loss.


"Howard Knight" <howardkinsd@yaEXPUNGEhoo.com> wrote in message
news:11ak23tensjvm95@corp.supernews.com...

First, let me tell you that I'm a retard when it comes to electronic
stuff. Anyway...

I was fiddling around behind my computer and got a nice shock. I'm
trying to figure out this problem and am hoping you folks could
help me out.

I get the shock when I touch any part of the back of my computer or
wires, and also touch the metal part of the cable that comes in and
connects to my cable modem. Here's the deal:

I live in an older house that is not grounded. The ground prong on
the outlets isn't connected to ground or anything else. Also, I've
determined that the coax cable coming in to my cable modem is
grounded. Somthing seems to be making the ground prong on my outlet
hot. I've narrowed down the problem to my power strip. I've
unplugged everything from my outlet and I check the outlet for
voltage. Neutral to hot gives me 110V. Neutral to ground give me
nothing (actually, for some odd reason, there does seem to be a
slight voltage (less than 2V). Hot to ground also gives me nothing.
As one would expect.

Now, if I plug in a power strip and do the same check on one of the
outlets on the power strip, I get: neutral to hot 110V, neutral to
ground around 60V and hot to ground around 60V. Is this right?
I've checked this with two power strips and I get the same results.
What would cause this? Is the polarity on my outlet wrong? Or,
am I just a dummy and am misintepreting what is going on. This
misterious 60V is what give me the shock.

Howard

 

[Keyser Soze]

<MSLaaf@gmail.com> wrote in message
news:1119024484.839145.126100@o13g2000cwo.googlegroups.com...

Hello,

I am trying to find out whether the HP 9133D drive would be supported
on the HP 1631D logic analyzer. Does anyone know which protocol this LA
uses? Is it Amigo, CS/80 or SS/80.

I found a remark somewhere which mentioned that there was a Harddrive
unit supported on this LA - but no details which one...

Thanks,

Maurice

The manual I have only refers to the HP 9121S or the HP 9121D
"Flexible Disc Drive". This type of drive holds one or two 3.5"
floppy drives.

My manual was printed before there were HP 9133D drive units.

The 1631D may not know how to deal with a 15mb disk drive.

 

[Robert Baer]

Mike Sampieri wrote:

Hello -

I have a new 23" CRT computer monitor, which degausses itself when turned
on.
I also have a color laser printer right next to the monitor - about 8
inches.

Since this monitor is so large, hence the degaussing coil is so "strong",
can the EMF field damage the printer circuitry? Or a computer?

If so, what's a good distance to keep away from the monitor, for electronic
devices and printers? 1 foot? 2 feet?

Thanks for any advice!

-Mike

Not a problem.

The only time the degausser operates is during AC power on.
And the field strength is maximumin the middle; 8 inches away and
especially to a side, it is too weak to consider.
*** "alt.electronics is not a valid NG" ***

 

[Russ]

As you probably know the Boardmaster 4000 is discontiuned. But ABI makes
newer models and at least they are still in business. They have two compact
testers one digital and one analog. They are the same as the B&K models
just repackaged. CapeElectronics is one of the few importers of the ABI
stuff. I saw a broken 4000 just sell on ebay. They seem rare.
<invadar@mail.com> wrote in message
news:1118390029.227824.124650@o13g2000cwo.googlegroups.com...

invadar@mail.com Jun 10, 8:23 am show options


Hi All,
I am new to this group and my interest is repairing
pcb's and monitors for video games.


I am looking to aquire a Boardmaster 4000 IC tester
(must be working and complete)
I will pay cash or maybe PX a Fluke 9010a micro system troubleshooter.


also i would like to hear from anyone who has had experience
of using the boardmaster.


Thanks in advance Pete (invadar)

 

[Peter A Forbes]

On Sun, 26 Jun 2005 16:30:19 +0100, Zak <zak@nomail.invalid> wrote:

How do bargain basement modern digital meters perform compared to
the old analogue meters from 30 years ago like the AVOmeter?

-----------

Thirty-odd years ago my friends had AVOmeters. I would look on
with some envy. Remember AVOs? I think they were mainly a UK
thing. 10 by 8 inches and about 4 inches thick. See this:-
http://www.richardsradios.co.uk/Images/AVO.jpg

Today I can buy a regularly stocked item like the super-cheapo
single-chip digital multimeter from a UK shop like Maplins for Ł8
($8) and that includes the battery. Although Maplins call it a
"domestic tester" it is more than just that:

600V-200V-20V-2000mV-200mV plus 600VAC-200VAC
10A-200mA-20mA-2000uA-200uA
2000kO-200kO-20kO-2000O-200O
transistor and functions
overall accuracy approx +/-0.5% to +/-1.0%

http://www.maplin.co.uk/module.aspx?ModuleNo=37279&doy=26m6

How does something as ridiculously cheap as this meter compare, in
terms of measurement accuracy, to an old stye AVOmeter?

Depends on what you want it for.

We have an AVO 8 or two, and keep them for the occasional job where we need to
see movement rather than digits changing.

Accuracy is possibly better with the Flukes we also have, but it's all a matter
of interpretation and setting anyway, so we tend to keep the AVO for those
occasions where it is really useful, such as measuring resistance and for
indicative work.

The Flukes absolutely eat batteries, we must have paid their price over and over
in replacement batteries!

Pity Philips got out of the testmeter business, their digital meters were far
better than Fluke IMO, and they had much larger batteries....

Peter

 

[asmagal]

Dear Rob,

I must apologize for disturbing you, but I would like to know if, and how,
did you solve the probe finding problem for your HP 4815A. I knew that you
had this difficulty through your message posted on the 01/26/2004 on this
list and
I am at present having the same problem.

Your help should be very much appreciated.
Best 73's
Antonio=CT1TE

 

[MIC]

hi there,
I also need a copy of the PM2525 manual. If you would email this I
would appreciate it, thank you. this is my email. mmcgu99@yahoo.com.

 

[Ed Bailen]

On Sat, 25 Jun 2005 16:48:16 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

"TimPerry" <timperry@noaspamadelphia.net> wrote in message
news:XpednVOXYoVDLyDfRVn-vw@adelphia.com...

"Kathleen Carmody" <councilmembercarmody@ci.brooklyn-center.mn.us
wrote in
message news:Ma2dna19_uD9OCDfRVnyjw@skypoint.com...

(-PLEASE- No lectures or legal suppositions needed or desired)

Anyone know where to purchase a cellular phone jammer, preferably
stateside. There are vendors off shore, but none here in CONUS
that I know of. Please post here any US vendors that sell cellular
jammers. (Extra points for relating your experience with using one.)


yes indeed: google search for "copper mesh".

simply surround the area you wish to sheild in the copper mesh
screening
(solid copper will work too but its harder to breathe through)

I've worked in a Faraday cage, so I know what you're saying is true.
But what I can't figure out is why the elevator at work, which has four
stainless steel walls, fails to stop my cell phone from working. Works
great, other than the elevator ride is too short. ;-)

Now here's something different. I work in the room with a half dozen
old PBXes for our phone system, each having a lotta old TTL circuitry on
big boards in a card cage. When I get near them, I can't get any signal
thru to the cell phone. Works great when I don't wanna be bugged by the
boss. ;-)


Unless the elevator doors close with RF gaskets, you have an open slot

that is many wavelengths long. To be effective, a faraday cage should
have no openings greater than about 1/10 wavelength at the highest
shielded frequency.

Regards,
Ed

 

[Michael A. Terrell]

arem_29 wrote:

hi!... i think this one one might help those who deals with electronic
problems, and they got manuals there!.. i just think it can be useful
for the members, thats why im sharing it.. well, i hope it is..
anyways, here's the link,

Enough already. Most people alreday know about that site and don't
need constant reminders on every newsgroup.

--
http://home.earthlink.net/~computersforvets/

Michael A. Terrell
Central Florida

 

[Dave Garnett]

Hi,
I need program ATmega8. Is ISP load cable will be enough for example:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50915&item=7529042935&rd=1&ssPageName=WDVW
or I need something else ?

It might work, but I'd spend the money to get a 'real' Atmel AVRISP. I note
that the firmware for it seems to get updated with each release of the AVR
Studio, and I'd wonder about support coming from anyone except Atmel ... My
experience of third party ISP programmers has been mixed, with particular
problems at lower voltages.

And if you add a suitable header to your project you don't need anything
else to program it - but you'd better read the programming section of the
datasheet carefully to make sure that you don't get any clashes with your
logic.

Dave




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