P
Phil Allison
Guest
"Dave Plowman "Pommy Nutcase"
** Shame it is not in the USA - you steaming great fuckwit.
.... Phil
** Shame it is not in the USA - you steaming great fuckwit.
.... Phil
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Phil Allison
Guest
"Wild_Bill"
** One what ??
The question is not about the number but the nature of the item.
.... Phil
MCM Electronics has one.
** One what ??
The question is not about the number but the nature of the item.
.... Phil
D
Dave Plowman (News)
Guest
In article <87fshcF1r7U1@mid.individual.net>,
Phil Allison <phil_a@tpg.com.au> wrote:
don't understand what 'isolate' means...
--
*I don't suffer from insanity -- I'm a carrier
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
Phil Allison <phil_a@tpg.com.au> wrote:
Surely an isolation transformer is just that...
Given your supreme command of the English language it's not a surprise you** Shame it is not in the USA - you steaming great fuckwit.
don't understand what 'isolate' means...
--
*I don't suffer from insanity -- I'm a carrier
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
J
JW
Guest
On Thu, 10 Jun 2010 13:42:19 -0700 PlainBill47@yahoo.com wrote in Message
id: <7dj216h43dpi27vfrr5ccb2p11clin2is8@4ax.com>:
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
id: <7dj216h43dpi27vfrr5ccb2p11clin2is8@4ax.com>:
Nice price. I'm working on a 1KW HP 6032A power supply (with outputsOn Thu, 10 Jun 2010 09:44:12 -0400, JW <none@dev.null> wrote:
Can anyone recommend a good isolation transformer for sale on-line?
Need one that will handle 5 amps or so at 120VAC, and have a standard AC
plug at the outlet. Prefer one for less than $100 or so, unless that seems
unreasonable. Found one at Mouser for $114 but that's only good for 1.25A.
Getting lots of irrelevant hits on google...
Thanks.
Here's one on eBay. 4.35A for about $75 delivered.
http://cgi.ebay.com/Stancor-GIS-500-Isolation-Transformer-115v-out-115v-/250643065589?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3a5b7daaf5
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
J
JW
Guest
On Fri, 11 Jun 2010 10:30:56 +1000 "Phil Allison" <phil_a@tpg.com.au>
wrote in Message id: <87dee7Fdj9U1@mid.individual.net>:
kill myself!
wrote in Message id: <87dee7Fdj9U1@mid.individual.net>:
Galvanic. Thanks - didn't realize there are different kinds. Don't want to"JW"
Can anyone recommend a good isolation transformer for sale on-line?
** What kind ??
There are two:
1. Galvanic isolation - for use on a service bench.
kill myself!
D
Dave Plowman (News)
Guest
In article <jqp6161lis3v93582a2p4q6g9212udvqpt@4ax.com>,
JW <none@dev.null> wrote:
devices like this. What is the point of an isolating transformer which
doesn't isolate?
--
*When a clock is hungry it goes back four seconds*
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
JW <none@dev.null> wrote:
It certainly seems to me stupid to have the same name for differentOn Fri, 11 Jun 2010 10:30:56 +1000 "Phil Allison" <phil_a@tpg.com.au
wrote in Message id: <87dee7Fdj9U1@mid.individual.net>:
"JW"
Can anyone recommend a good isolation transformer for sale on-line?
** What kind ??
There are two:
1. Galvanic isolation - for use on a service bench.
Galvanic. Thanks - didn't realize there are different kinds. Don't want
to kill myself!
devices like this. What is the point of an isolating transformer which
doesn't isolate?
--
*When a clock is hungry it goes back four seconds*
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
J
JW
Guest
On Fri, 11 Jun 2010 08:24:36 -0500 Chuck <ch@deja.net> wrote in Message
id: <r7e416tt40mloqh91evegbjo9eb2qllqjk@4ax.com>:
http://www.mcmelectronics.com/product/TRIPP-LITE--POWER-PROTECTION--IS500-/28-10160
http://www.mcmelectronics.com/product/TENMA-72-1097-/72-1097
A bit more than I wanted to spend and a little less current capability,
but those may be the breaks.
id: <r7e416tt40mloqh91evegbjo9eb2qllqjk@4ax.com>:
Thanks Chuck. Looking at these for the moment:On Thu, 10 Jun 2010 09:44:12 -0400, JW <none@dev.null> wrote:
Can anyone recommend a good isolation transformer for sale on-line?
Need one that will handle 5 amps or so at 120VAC, and have a standard AC
plug at the outlet. Prefer one for less than $100 or so, unless that seems
unreasonable. Found one at Mouser for $114 but that's only good for 1.25A.
Getting lots of irrelevant hits on google...
Thanks.
MCM Electronics has one. Chuck
http://www.mcmelectronics.com/product/TRIPP-LITE--POWER-PROTECTION--IS500-/28-10160
http://www.mcmelectronics.com/product/TENMA-72-1097-/72-1097
A bit more than I wanted to spend and a little less current capability,
but those may be the breaks.
P
PeterD
Guest
On Sat, 12 Jun 2010 06:53:47 -0400, JW <none@dev.null> wrote:
You need to make 100% sure your life insurance is fully paid up. <g>...
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
T
tm
Guest
"JW" <none@dev.null> wrote in message
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
you have a two channel scope with invert on channel 2?
Tom
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
This is a "bad idea". Better to use a differential input and two probes. DoNice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
you have a two channel scope with invert on channel 2?
Tom
P
Phil Allison
Guest
"Dave Plowman " Rabid Pommy Nutcase"
** Shame it is not so in the USA
- you Steaming Great Fuckwit ...............
.... Phil
Can anyone recommend a good isolation transformer for sale on-line?
** What kind ??
There are two:
1. Galvanic isolation - for use on a service bench.
2. Neutral conductor isolation.
Most you see offered for sale in the USA are of the *second* kind.
Surely an isolation transformer is just that...
** Shame it is not so in the USA
- you Steaming Great Fuckwit ...............
.... Phil
Guest
On Sat, 12 Jun 2010 06:53:47 -0400, JW <none@dev.null> wrote:
the power supply at some potentially lethal voltage, so use extreme
caution.
Somewhere in my kit (probably with the isolation transformer I can't
find) is an adapter to use a grounded (three prong) plug in an
ungrounded (two prong) outlet. I used that when working with any
devide that required the isolation transformer. I also carefully
verified that the isolation was indeed effective; I had no desire to
watch my scope probe's ground lead vaporize.
PlainBill
must be isolated. Note that this may well leave the metal chassis ofOn Thu, 10 Jun 2010 13:42:19 -0700 PlainBill47@yahoo.com wrote in Message
id: <7dj216h43dpi27vfrr5ccb2p11clin2is8@4ax.com>:
On Thu, 10 Jun 2010 09:44:12 -0400, JW <none@dev.null> wrote:
Can anyone recommend a good isolation transformer for sale on-line?
Need one that will handle 5 amps or so at 120VAC, and have a standard AC
plug at the outlet. Prefer one for less than $100 or so, unless that seems
unreasonable. Found one at Mouser for $114 but that's only good for 1.25A.
Getting lots of irrelevant hits on google...
Thanks.
Here's one on eBay. 4.35A for about $75 delivered.
http://cgi.ebay.com/Stancor-GIS-500-Isolation-Transformer-115v-out-115v-/250643065589?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3a5b7daaf5
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
That SHOULD be the correct isolation transformer. And yes, the ground
the power supply at some potentially lethal voltage, so use extreme
caution.
Somewhere in my kit (probably with the isolation transformer I can't
find) is an adapter to use a grounded (three prong) plug in an
ungrounded (two prong) outlet. I used that when working with any
devide that required the isolation transformer. I also carefully
verified that the isolation was indeed effective; I had no desire to
watch my scope probe's ground lead vaporize.
PlainBill
D
Dave Plowman (News)
Guest
In article <hv06fk$jkb$1@news-01.bur.connect.com.au>,
Phil Allison <phil_a@tpg.com.au> wrote:
to use bad language when visiting. If you'd ever known your parents they'd
have likely taught you the same.
--
*If at first you don't succeed, redefine success.
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
Phil Allison <phil_a@tpg.com.au> wrote:
Surely an isolation transformer is just that...
But I'm not in the USA and neither are you. However, at least I know not** Shame it is not so in the USA
- you Steaming Great Fuckwit ...............
to use bad language when visiting. If you'd ever known your parents they'd
have likely taught you the same.
--
*If at first you don't succeed, redefine success.
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
Guest
On Sat, 12 Jun 2010 10:32:04 -0400, "tm" <noone@msc.com> wrote:
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
PlainBill
to use an isolation transformer when servicing TVs and other 'live"JW" <none@dev.null> wrote in message
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
This is a "bad idea". Better to use a differential input and two probes. Do
you have a two channel scope with invert on channel 2?
Tom
That would be news to large numbers of electronics technicians who had
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
PlainBill
D
Dave Plowman (News)
Guest
In article <j7g716l13t96u9322qmqjiv8r5ppua3tdj@4ax.com>,
<PlainBill47@yahoo.com> wrote:
ground even with a 'live' chassis. The only way to get an electrical shock
is to touch both outputs from the transformer.
--
*Why isn't there a special name for the back of your knee?
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
<PlainBill47@yahoo.com> wrote:
If using a proper isolating transformer, there will be no reference toThat would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
ground even with a 'live' chassis. The only way to get an electrical shock
is to touch both outputs from the transformer.
--
*Why isn't there a special name for the back of your knee?
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
T
tm
Guest
<PlainBill47@yahoo.com> wrote in message
news:j7g716l13t96u9322qmqjiv8r5ppua3tdj@4ax.com...
the inverted second channel and can be used to look at a signal that is
raised above
ground. No isolation transformer is needed and it is IMO, safer.
YMMV.
news:j7g716l13t96u9322qmqjiv8r5ppua3tdj@4ax.com...
You can do it anyway you want. Just that many good scopes have a way to addOn Sat, 12 Jun 2010 10:32:04 -0400, "tm" <noone@msc.com> wrote:
"JW" <none@dev.null> wrote in message
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability)
and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I
need
to isolate (disconnect) the ground on the 6032A power supply under
repair?
Thanks.
This is a "bad idea". Better to use a differential input and two probes.
Do
you have a two channel scope with invert on channel 2?
Tom
That would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
PlainBill
the inverted second channel and can be used to look at a signal that is
raised above
ground. No isolation transformer is needed and it is IMO, safer.
YMMV.
M
Meat Plow
Guest
On Sat, 12 Jun 2010 10:20:10 -0700, PlainBill47 ÇĘoÉšĘ:
3Aman&lc=eng&cc=US&nfr=-35687.384731On Sat, 12 Jun 2010 10:32:04 -0400, "tm" <noone@msc.com> wrote:
"JW" <none@dev.null> wrote in message
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability)
and need to connect my scope to the hot side of a switching
transformer - specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?
action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%
Serviced many GE VIR portables with a Sencore PR57 Powerite.Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes
GND lead the source of Q1 and probe the it's gate to check the it,
then move the scopes GND lead to Q3's drain lead to check it's gate
drive.
Given that, would that Ebay transformer be the right choice, and do I
need to isolate (disconnect) the ground on the 6032A power supply
under repair?
Thanks.
This is a "bad idea". Better to use a differential input and two
probes. Do you have a two channel scope with invert on channel 2?
Tom
That would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
PlainBill
W
Wild_Bill
Guest
Apparently you assume that I didn't understand that.
--
Cheers,
WB
..............
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:huukoc$q2e$1@news-01.bur.connect.com.au...
--
Cheers,
WB
..............
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:huukoc$q2e$1@news-01.bur.connect.com.au...
The question is not about the number but the nature of the item.
.... Phil
M
Michael A. Terrell
Guest
PlainBill47@yahoo.com wrote:
That advice was quite valid when two channel scopes weren't seen
outside of a factory or research center.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
On Sat, 12 Jun 2010 10:32:04 -0400, "tm" <noone@msc.com> wrote:
"JW" <none@dev.null> wrote in message
news:0qo616dhg4nsgshqjsia9l39venjef4bt6@4ax.com...
Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability) and
need to connect my scope to the hot side of a switching transformer -
specifically the source and drains on the output FETs.
Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.
With an isolation transformer, I *think* I would connect the scopes GND
lead the source of Q1 and probe the it's gate to check the it, then move
the scopes GND lead to Q3's drain lead to check it's gate drive.
Given that, would that Ebay transformer be the right choice, and do I need
to isolate (disconnect) the ground on the 6032A power supply under repair?
Thanks.
This is a "bad idea". Better to use a differential input and two probes. Do
you have a two channel scope with invert on channel 2?
Tom
That would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
That advice was quite valid when two channel scopes weren't seen
outside of a factory or research center.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
M
Michael A. Terrell
Guest
"Dave Plowman (News)" wrote:
Not true. You connect the chassis of the UUT to the test equipment,
so ANY voltage you contact inside the UUT is referenced to ground.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
In article <j7g716l13t96u9322qmqjiv8r5ppua3tdj@4ax.com>,
PlainBill47@yahoo.com> wrote:
That would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.
If using a proper isolating transformer, there will be no reference to
ground even with a 'live' chassis. The only way to get an electrical shock
is to touch both outputs from the transformer.
Not true. You connect the chassis of the UUT to the test equipment,
so ANY voltage you contact inside the UUT is referenced to ground.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
P
Phil Allison
Guest
"tm"
available with that scope function.
The buffers on most ( analogue) scopes become overloaded with input signals
that exceed full screen hight by a factor of 2 or 3 times.
Say you want to examine a 1 volt p-p signal and you set the scope input
atten to 0.5 volts per division - then the largest undistorted input
allowable is gonna be about 0.5 x 8 x 3 = 12 volts p-p.
Not much use with the ACTUAL common mode signal is several hundred volts p-p
from rectified AC supply.
..... Phil
** The problem with that idea is the very limited common mode rangeYou can do it anyway you want. Just that many good scopes have a way to
add
the inverted second channel and can be used to look at a signal that is
raised above ground.
available with that scope function.
The buffers on most ( analogue) scopes become overloaded with input signals
that exceed full screen hight by a factor of 2 or 3 times.
Say you want to examine a 1 volt p-p signal and you set the scope input
atten to 0.5 volts per division - then the largest undistorted input
allowable is gonna be about 0.5 x 8 x 3 = 12 volts p-p.
Not much use with the ACTUAL common mode signal is several hundred volts p-p
from rectified AC supply.
** Fraid that is just not true when dealing with off-line SMPS.No isolation transformer is needed and it is IMO, safer.
..... Phil