T
Tobias Gadelha
Guest
Is there any risk to use oscilloscope without wire ground? Because with wire ground there is a short circuit when I use GND on the line.
R
Rich Webb
Guest
On Sun, 28 Jul 2013 11:49:54 -0700 (PDT), Tobias Gadelha
<tobiasgadelha@gmail.com> wrote:
<http://www.darwinawards.com/> for proper attribution. Thanks!
<tobiasgadelha@gmail.com> wrote:
Simply ensure that your contact information is forwarded to
<http://www.darwinawards.com/> for proper attribution. Thanks!
T
Tom Biasi
Guest
On 7/28/2013 2:49 PM, Tobias Gadelha wrote:
H
Helmut Wabnig
Guest
On Sun, 28 Jul 2013 12:50:23 -0700 (PDT), Tobias Gadelha
<tobiasgadelha@gmail.com> wrote:
Use a dual channel scope with two probes and display the difference.
This is the regular way to do it.
Trick 2:
I have also done the GROUND removal trick,
but I am an expert in electrocution.
On my scope I mounted an extra connector to disconnect
the green/yello wire momentarily.
better you do Trick one I described above.
w.
<tobiasgadelha@gmail.com> wrote:
Trick 1:
Use a dual channel scope with two probes and display the difference.
This is the regular way to do it.
Trick 2:
I have also done the GROUND removal trick,
but I am an expert in electrocution.
On my scope I mounted an extra connector to disconnect
the green/yello wire momentarily.
better you do Trick one I described above.
w.
J
Jim Thompson
Guest
On Sun, 28 Jul 2013 22:19:13 +0200, Helmut Wabnig <hwabnig@.- ---
-.dotat> wrote:
a TEK probe that provided isolation from ground for such measurements,
so that I could probe off-line switchers safely. You might want to
track one of those down _before_ you electrocute yourself ;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
-.dotat> wrote:
Back in the 1977-1987 time-frame (OmniComp/GenRad days) I used to have
a TEK probe that provided isolation from ground for such measurements,
so that I could probe off-line switchers safely. You might want to
track one of those down _before_ you electrocute yourself ;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
J
John Fields
Guest
On Sun, 28 Jul 2013 12:50:23 -0700 (PDT), Tobias Gadelha
<tobiasgadelha@gmail.com> wrote:
Use a 2 channel scope which can invert one channel and add the two
channels.
Connect the grounds of both probes to mains ground, the channel which
doesn't invert to L1, the channel which does invert to L2, invert the
channel, and add the two channels.
Also, it would be a good idea to set the sensitivity (volts per box)
of both channels equal.
Start off high and work down.
--
JF
<tobiasgadelha@gmail.com> wrote:
---
Use a 2 channel scope which can invert one channel and add the two
channels.
Connect the grounds of both probes to mains ground, the channel which
doesn't invert to L1, the channel which does invert to L2, invert the
channel, and add the two channels.
Also, it would be a good idea to set the sensitivity (volts per box)
of both channels equal.
Start off high and work down.
--
JF
T
Tobias Gadelha
Guest
Em domingo, 28 de julho de 2013 16h16min59s UTC-3, Tom Biasi escreveu:
but I need measure line (L1) with reference in line(L2).
J
John G
Guest
Tobias Gadelha has brought this to us :
power.
IT WILL KILL YOU :-@
--
John G
The real answer is ___ You do not know enough to be fooling with mains
power.
IT WILL KILL YOU :-@
--
John G
J
John Larkin
Guest
On Sun, 28 Jul 2013 12:50:23 -0700 (PDT), Tobias Gadelha
<tobiasgadelha@gmail.com> wrote:
ratio with a DVM.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
<tobiasgadelha@gmail.com> wrote:
Use a small transformer to isolate and step down the voltage. Calibrate the
ratio with a DVM.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
P
Phil Allison
Guest
"Tobias Gadelha"
** L1 or L2 will be at the almost same potential as ground - so you have no
real problem.
..... Phil
** L1 or L2 will be at the almost same potential as ground - so you have no
real problem.
..... Phil
D
Daniel Pitts
Guest
On 7/28/13 11:50 PM, Phil Allison wrote:
D
Daniel Pitts
Guest
On 7/28/13 11:49 AM, Tobias Gadelha wrote:
question... Are you talking about the ground in the plug, or the ground
for the probe? It would surprise me greatly if they were connected. I
would *think* that you could connect the probe's GND to a line with any
potential.
I would expect only the relative potential to where the other part of
the oscilloscope is connected need to be within range for the scope, but
not with reference to the earth.
I could very will be extremely wrong about all this, but and would love
to be corrected before I end up passing high voltage through my body ;-)
Thanks,
Daniel.
I'm just learning this stuff myself, but I have a question about your
question... Are you talking about the ground in the plug, or the ground
for the probe? It would surprise me greatly if they were connected. I
would *think* that you could connect the probe's GND to a line with any
potential.
I would expect only the relative potential to where the other part of
the oscilloscope is connected need to be within range for the scope, but
not with reference to the earth.
I could very will be extremely wrong about all this, but and would love
to be corrected before I end up passing high voltage through my body ;-)
Thanks,
Daniel.
T
Tom Biasi
Guest
On 7/29/2013 12:23 PM, Daniel Pitts wrote:
See number 11.
Look here: http://www.allaboutcircuits.com/worksheets/scope1.html
See number 11.
F
Fred Abse
Guest
On Sun, 28 Jul 2013 11:49:54 -0700, Tobias Gadelha wrote:
NEVER disconnect the supply ground from your instrument. It could be all
that stands between you and a day out with the undertaker.
--
"Design is the reverse of analysis"
(R.D. Middlebrook)
Use a differential probe, or A-B, if your 'scope has the facility.
NEVER disconnect the supply ground from your instrument. It could be all
that stands between you and a day out with the undertaker.
--
"Design is the reverse of analysis"
(R.D. Middlebrook)
P
Phil Allison
Guest
"Daniel Pitts"
Phil Allison wrote:
Make your point or piss off.
Phil Allison wrote:
** About what exactly ?
Make your point or piss off.
D
Daniel Pitts
Guest
On 7/29/13 5:43 PM, Phil Allison wrote:
was curious how you did.
My point should have been relatively clear, but I can see it was
ambiguous with the "so you have no real problem". So, now that I've
clarified, I'd like a real answer. Unless you've realized you were
wrong, then a simple note to that effect would also be polite.
Thanks,
Daniel.
ground" is true? I don't understand how you came to that conclusion so I
was curious how you did.
is. No need to get rude.
My point should have been relatively clear, but I can see it was
ambiguous with the "so you have no real problem". So, now that I've
clarified, I'd like a real answer. Unless you've realized you were
wrong, then a simple note to that effect would also be polite.
Thanks,
Daniel.
D
Daniel Pitts
Guest
On 7/29/13 11:41 AM, Tom Biasi wrote:
safer way to handle this situation. Thanks for the lesson ;-)
likely depending on the OPs application, coupling transformers may be a
safer way to handle this situation. Thanks for the lesson ;-)
P
Phil Allison
Guest
"Daniel Pitts"
Phil Allison wrote:
active and neutral conductors.
( Nothing suggested the OP was dealing with 3 phase power and I hope to
hell he is not)
Neutral conductors are always linked to ground at the service box.
So, the voltage seen from active to ground is almost the same as that from
to active to neutral - the only difference being due to current in the
particular neutral wire due to some load.
Get your DMM out and check it sometime.
.... Phil
Phil Allison wrote:
** The codes L1 and L2 are very often seen on schematics refering to the
active and neutral conductors.
( Nothing suggested the OP was dealing with 3 phase power and I hope to
hell he is not)
Neutral conductors are always linked to ground at the service box.
So, the voltage seen from active to ground is almost the same as that from
to active to neutral - the only difference being due to current in the
particular neutral wire due to some load.
Get your DMM out and check it sometime.
.... Phil
T
Tom Biasi
Guest
On 7/29/2013 10:23 PM, Phil Allison wrote:
Confusion with terminology is dangerous. This is a basic group.
Tom
but not always. L1 and L2 are usually hot wires wrt ground.
Confusion with terminology is dangerous. This is a basic group.
Tom
D
Daniel Pitts
Guest
On 7/29/13 7:23 PM, Phil Allison wrote: