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Abusing brick on the rope

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  Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-02 12:55 -0700
    Re: Abusing brick on the rope tabbypurr@gmail.com - 2018-10-02 13:12 -0700
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-02 13:35 -0700
        Re: Abusing brick on the rope tabbypurr@gmail.com - 2018-10-02 16:13 -0700
          Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-02 17:04 -0700
            Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-02 17:19 -0700
              Re: Abusing brick on the rope tabbypurr@gmail.com - 2018-10-02 17:47 -0700
              Re: Abusing brick on the rope Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-02 18:16 -0700
              Re: Abusing brick on the rope Jon Elson <elson@pico-systems.com> - 2018-10-03 14:09 -0500
                Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:37 -0700
                Re: Abusing brick on the rope <698839253X6D445TD@nospam.org> - 2018-10-04 06:19 +0000
        Re: Abusing brick on the rope DLUNU <DecadentLinuxUserNumeroUno@DLU.org> - 2018-10-03 01:47 +0000
          Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 06:11 -0700
            Re: Abusing brick on the rope Steve Wilson <no@spam.com> - 2018-10-03 13:17 +0000
              Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 06:36 -0700
                Re: Abusing brick on the rope gnuarm.deletethisbit@gmail.com - 2018-10-03 10:02 -0700
                Re: Abusing brick on the rope krw@notreal.com - 2018-10-03 22:14 -0400
              Re: Abusing brick on the rope DLUNU <DecadentLinuxUserNumeroUno@DLU.org> - 2018-10-03 16:27 +0000
                Re: Abusing brick on the rope gnuarm.deletethisbit@gmail.com - 2018-10-03 10:04 -0700
            Re: Abusing brick on the rope DLUNU <DecadentLinuxUserNumeroUno@DLU.org> - 2018-10-03 16:25 +0000
    Re: Abusing brick on the rope piglet <erichpwagner@hotmail.com> - 2018-10-02 21:25 +0100
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-02 13:48 -0700
        Re: Abusing brick on the rope Jon Elson <elson@pico-systems.com> - 2018-10-03 14:15 -0500
          Re: Abusing brick on the rope Phil Allison <pallison49@gmail.com> - 2018-10-03 15:18 -0700
            Re: Abusing brick on the rope tabbypurr@gmail.com - 2018-10-03 17:26 -0700
              Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:52 -0700
            Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:45 -0700
            Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-11 12:22 -0700
    Re: Abusing brick on the rope John Robertson <spam@flippers.com> - 2018-10-02 15:32 -0700
    Re: Abusing brick on the rope Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-02 15:56 -0700
    Re: Abusing brick on the rope Jasen Betts <jasen@xnet.co.nz> - 2018-10-03 00:58 +0000
    Re: Abusing brick on the rope Phil Allison <pallison49@gmail.com> - 2018-10-02 23:23 -0700
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 06:16 -0700
    Re: Abusing brick on the rope Phil Allison <pallison49@gmail.com> - 2018-10-02 23:25 -0700
    Re: Abusing brick on the rope <698839253X6D445TD@nospam.org> - 2018-10-03 07:30 +0000
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 06:19 -0700
        Re: Abusing brick on the rope <698839253X6D445TD@nospam.org> - 2018-10-03 14:01 +0000
          Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 07:12 -0700
            Re: Abusing brick on the rope <698839253X6D445TD@nospam.org> - 2018-10-04 06:20 +0000
      Re: Abusing brick on the rope Jon Elson <elson@pico-systems.com> - 2018-10-03 14:20 -0500
        Re: Abusing brick on the rope Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-03 12:27 -0700
          Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:58 -0700
            Re: Abusing brick on the rope <698839253X6D445TD@nospam.org> - 2018-10-04 06:20 +0000
        Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:36 -0700
    Re: Abusing brick on the rope Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> - 2018-10-03 12:39 +0300
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 06:22 -0700
    Re: Abusing brick on the rope Ingvald44 <noone@nowhere.com> - 2018-10-03 08:02 -0400
    Re: Abusing brick on the rope Jon Elson <elson@pico-systems.com> - 2018-10-03 14:07 -0500
      Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-03 17:24 -0700
        Re: Abusing brick on the rope Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-04 12:45 -0400
          Re: Abusing brick on the rope George Herold <gherold@teachspin.com> - 2018-10-04 10:01 -0700

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#518237

onsdag den 3. oktober 2018 kl. 21.20.24 UTC+2 skrev Jon Elson:
> On Wed, 03 Oct 2018 07:30:14 +0000, 698839253X6D445TD wrote:
> 
> 
> > It being a school, it would not surprise me (has your 'thing' any
> > output? if 'they' (accidently??) put some ...mains into your output and
> > that way in reverse killed your unit and that power supply (a more
> > common word) too.
> > He 'whodiddit' will remain anonymous and life goes on.
> > In that worst case they will do it again with the new replacement.
> > From a legal POV you can use an expert witness to show your thing could
> > not be the cause. Shit situation.
> It would not be a bad idea at ALL to have the school check all equipment 
> used at that bench or whatever for power supply faults, bad grounds, open 
> grounds and whatever.
> 
> I got knocked on my rear (literally) by an open ground in my lab at work 
> when I had a scope and logic analyzer hooked up, and touched something 
> that was connected to my computer on a properly grounded outlet.  I have 
> NO IDEA how long the ground on that outlet had been in that condition.
> 

most outlets here have no ground so if you touch ground and anything with 
a smsp you get a shock, but it is only a tingle

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#518284

On Wednesday, October 3, 2018 at 3:27:17 PM UTC-4, Lasse Langwadt Christensen wrote:
> onsdag den 3. oktober 2018 kl. 21.20.24 UTC+2 skrev Jon Elson:
> > On Wed, 03 Oct 2018 07:30:14 +0000, 698839253X6D445TD wrote:
> > 
> > 
> > > It being a school, it would not surprise me (has your 'thing' any
> > > output? if 'they' (accidently??) put some ...mains into your output and
> > > that way in reverse killed your unit and that power supply (a more
> > > common word) too.
> > > He 'whodiddit' will remain anonymous and life goes on.
> > > In that worst case they will do it again with the new replacement.
> > > From a legal POV you can use an expert witness to show your thing could
> > > not be the cause. Shit situation.
> > It would not be a bad idea at ALL to have the school check all equipment 
> > used at that bench or whatever for power supply faults, bad grounds, open 
> > grounds and whatever.
> > 
> > I got knocked on my rear (literally) by an open ground in my lab at work 
> > when I had a scope and logic analyzer hooked up, and touched something 
> > that was connected to my computer on a properly grounded outlet.  I have 
> > NO IDEA how long the ground on that outlet had been in that condition.
> > 
> 
> most outlets here have no ground so if you touch ground and anything with 
> a smsp you get a shock, but it is only a tingle

Wow,  so the 'scope plugged into the same AC is also floating?
Do you hook onto the plumbing?  

George H.  

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#518303

George Herold wrote
>Wow,  so the 'scope plugged into the same AC is also floating?

I deliberately removed the mains ground from my scope so I can measure things with some potential from ground,
and avoid ground loops.
You need to know what you are doing though.
Modern battery operated watch size 100 GHz scopes do not have that problem, are floating too.

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#518279

On Wednesday, October 3, 2018 at 3:20:24 PM UTC-4, Jon Elson wrote:
> On Wed, 03 Oct 2018 07:30:14 +0000, 698839253X6D445TD wrote:
> 
> 
> > It being a school, it would not surprise me (has your 'thing' any
> > output? if 'they' (accidently??) put some ...mains into your output and
> > that way in reverse killed your unit and that power supply (a more
> > common word) too.
> > He 'whodiddit' will remain anonymous and life goes on.
> > In that worst case they will do it again with the new replacement.
> > From a legal POV you can use an expert witness to show your thing could
> > not be the cause. Shit situation.
> It would not be a bad idea at ALL to have the school check all equipment 
> used at that bench or whatever for power supply faults, bad grounds, open 
> grounds and whatever.
> 
> I got knocked on my rear (literally) by an open ground in my lab at work 
> when I had a scope and logic analyzer hooked up, and touched something 
> that was connected to my computer on a properly grounded outlet.  I have 
> NO IDEA how long the ground on that outlet had been in that condition.
> 
> Jon

Hmmm, I haven't thought nearly enough about what happens if every
thing is floating (for some reason).  I figure to touch gnd lightly 
and let the 'scope or other piece of measurement apparatus define it. 

That's mostly worked so far. :^)

George H.  

 

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#518182

George Herold <gherold@teachspin.com> writes:

> Hi all, I just got done fixing a piece of apparatus that was returned
> to us.  The thing was trashed, (all sorts of blown components) and
> I've been trying to figure out what happened.  Perhaps what I found
> weirdest is a power monitor
> LED.  This sits across the +/-15 V rails, with a 12V zener and 5 k ohm 
> resistor in series.  (the zener stops it from turning on if one of the rails 
> fails.)  It just barley put out any light.... trashed.  
> It can take 30 mA forward so >~150 V for too much current.  
> And in reverse it doesn't break down till -80 V. 
> (I just tested it... it shows a photo response too, 
> but don't distract me.) 

How about this:
1. Ungrounded power supply with filter caps
2. Hot connection of power plug so that GND connects after supply rails
3. Apparatus grounded through some other route

This could discharge the mains filter cap through the power
rail. Depending on what's on the rail, the positive/negative discharge
could go through the LED.

--
mikko

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#518197

On Wednesday, October 3, 2018 at 5:39:16 AM UTC-4, Mikko OH2HVJ wrote:
> George Herold <gherold@teachspin.com> writes:
> 
> > Hi all, I just got done fixing a piece of apparatus that was returned
> > to us.  The thing was trashed, (all sorts of blown components) and
> > I've been trying to figure out what happened.  Perhaps what I found
> > weirdest is a power monitor
> > LED.  This sits across the +/-15 V rails, with a 12V zener and 5 k ohm 
> > resistor in series.  (the zener stops it from turning on if one of the rails 
> > fails.)  It just barley put out any light.... trashed.  
> > It can take 30 mA forward so >~150 V for too much current.  
> > And in reverse it doesn't break down till -80 V. 
> > (I just tested it... it shows a photo response too, 
> > but don't distract me.) 
> 
> How about this:
> 1. Ungrounded power supply with filter caps
> 2. Hot connection of power plug so that GND connects after supply rails
> 3. Apparatus grounded through some other route
> 
> This could discharge the mains filter cap through the power
> rail. Depending on what's on the rail, the positive/negative discharge
> could go through the LED.
> 
> --
> mikko

Hi Mikko thanks...   
Earth and ground,  (Earth being terminal on my AC wall outlet 
and ground being the case of the instrument.) are joined with 10 ohm R
which (as far as I could tell) was undamaged.  

George H. 

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#518186

On Tue, 2 Oct 2018 12:55:59 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

>Hi all, I just got done fixing a piece of apparatus that was returned to us.  The thing was trashed, (all sorts of blown components) and I've been trying to figure out what happened.  Perhaps what I found weirdest is a power monitor 
>LED.  This sits across the +/-15 V rails, with a 12V zener and 5 k ohm 
>resistor in series.  (the zener stops it from turning on if one of the rails 
>fails.)  It just barley put out any light.... trashed.  
>It can take 30 mA forward so >~150 V for too much current.  
>And in reverse it doesn't break down till -80 V. 
>(I just tested it... it shows a photo response too, 
>but don't distract me.) 
>
>So I was in contact with the school that was using this.. checking return 
>address, and I asked if they wanted a new brick on the rope.  (Because they 
>hadn't returned theirs with the unit.)  It was just then that I learned that 
>the brick on the rope had failed!!  And they had purchased a new one from the 
>vendor (astrodyne)  
>
>So my current theory is that the brick on the rope failed (somehow) 
>and blew 120 Vac through my circuit.. with devastating results.  
>Any idea how I can test this theory.. how do I blow up a brick on a 
>rope?  (Astrodyne Mod num. SPU45-210) +15 V @ +2A / -15V @ -1A.  
>
>Thanks
>George H. 
>(maybe I should contact astrodyne.)       


Microwave oven?

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#518230

On Tue, 02 Oct 2018 12:55:59 -0700, George Herold wrote:

>
> So my current theory is that the brick on the rope failed (somehow)
> and blew 120 Vac through my circuit.. with devastating results.
> Any idea how I can test this theory.. how do I blow up a brick on a
> rope?  (Astrodyne Mod num. SPU45-210) +15 V @ +2A / -15V @ -1A.

Are they in Florida (lightning capital of the world)?  Did any other gear 
in their lab go out at the same time?

Jon

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#518275

On Wednesday, October 3, 2018 at 3:08:05 PM UTC-4, Jon Elson wrote:
> On Tue, 02 Oct 2018 12:55:59 -0700, George Herold wrote:
> 
> >
> > So my current theory is that the brick on the rope failed (somehow)
> > and blew 120 Vac through my circuit.. with devastating results.
> > Any idea how I can test this theory.. how do I blow up a brick on a
> > rope?  (Astrodyne Mod num. SPU45-210) +15 V @ +2A / -15V @ -1A.
> 
> Are they in Florida (lightning capital of the world)?  Did any other gear 
> in their lab go out at the same time?
> 
> Jon

RPI on the banks of the Hudson. I was thinking, 
it was bad to post the name, but hey students are 
my final 'beta' testers. my hat's off to you.  
George H.  

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#518342

On 10/3/18 8:24 PM, George Herold wrote:
> On Wednesday, October 3, 2018 at 3:08:05 PM UTC-4, Jon Elson wrote:
>> On Tue, 02 Oct 2018 12:55:59 -0700, George Herold wrote:
>>
>>>
>>> So my current theory is that the brick on the rope failed (somehow)
>>> and blew 120 Vac through my circuit.. with devastating results.
>>> Any idea how I can test this theory.. how do I blow up a brick on a
>>> rope?  (Astrodyne Mod num. SPU45-210) +15 V @ +2A / -15V @ -1A.
>>
>> Are they in Florida (lightning capital of the world)?  Did any other gear
>> in their lab go out at the same time?
>>
>> Jon
> 
> RPI on the banks of the Hudson. I was thinking,
> it was bad to post the name, but hey students are
> my final 'beta' testers. my hat's off to you.
> George H.
> 

Home of the Troylets. ;)

Cheers

Phil Hobbs

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#518345

On Thursday, October 4, 2018 at 12:45:31 PM UTC-4, Phil Hobbs wrote:
> On 10/3/18 8:24 PM, George Herold wrote:
> > On Wednesday, October 3, 2018 at 3:08:05 PM UTC-4, Jon Elson wrote:
> >> On Tue, 02 Oct 2018 12:55:59 -0700, George Herold wrote:
> >>
> >>>
> >>> So my current theory is that the brick on the rope failed (somehow)
> >>> and blew 120 Vac through my circuit.. with devastating results.
> >>> Any idea how I can test this theory.. how do I blow up a brick on a
> >>> rope?  (Astrodyne Mod num. SPU45-210) +15 V @ +2A / -15V @ -1A.
> >>
> >> Are they in Florida (lightning capital of the world)?  Did any other gear
> >> in their lab go out at the same time?
> >>
> >> Jon
> > 
> > RPI on the banks of the Hudson. I was thinking,
> > it was bad to post the name, but hey students are
> > my final 'beta' testers. my hat's off to you.
> > George H.
> > 
> 
> Home of the Troylets. ;)
> 
> Cheers
> 
> Phil Hobbs

Huh, never heard of them.
"Troylets often participate in barbarian raids on Rensselaer Polytechnic Institute, a rich, fortified settlement deep within their territory. These raids are typically repelled by the campus militia, known as Public Safety. On occasion, the Troylet raiding parties make it as far as "The Union," one of RPI's most potent defenses, where they are lured into attempting skateboard tricks and subsequently knocking their teeth out and otherwise injuring themselves." 

Maybe they landed a skate board on the brick (on the rope). 

GH

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