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Re: Abusing brick on the rope

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George Herold <gherold@teachspin.com> wrote in
news:855d16d5-db6d-4d97-ad6f-63761c955eea@googlegroups.com: 

> On Tuesday, October 2, 2018 at 9:47:28 PM UTC-4, DLUNU wrote:
>> George Herold <gherold@teachspin.com> wrote in
>> news:69b19472-7334-4d87-9eb7-598e206a9036@googlegroups.com: 
>> 
>> > On Tuesday, October 2, 2018 at 4:12:49 PM UTC-4, tabb...@gmail.com
>> > wrote: 
>> >> On Tuesday, 2 October 2018 20:56:03 UTC+1, George Herold  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.)
>> >> 
>> >> why would you want to blow it up when you can bypass it?
>> >> 
>> >> 
>> >> NT
>> > 
>> > Bypass how?  I've got ~100 of these out in the field (class rooms)
>> > if there is a way to fry the power supply that then fried the
>> > electronics I'd like to know.  
>> > 
>> > George H. 
>> 
>>   It sounds like the result of a severe transient (lightning strike)
>>   on 
>> the input line to the brick which then passed it through in a rare 
>> failure mode.
>> 
>>   Instead of trying to recreate the failure, diagnose the failed unit
>> you already have and see if the isolated AC input side found a path 
>> through the PS to the output side.
>> 
>>   What device are you running that requires a dual output supply?
>>   That 
>> itself is an odd instance.
> 
> Right, I just don't know.  The professor seems adamant that the
> students did something wrong.  I can't diagnose the failed supply,
> 'cause I ain't got it.  
> 
> Dual supply +/-15V is for opamps.  I know they are rare these days
> (split supplies), but at the time it was easier than splitting some
> single supply. 
> 
> George H. 
> 

You could build an inline "minibrick" -15V supply to hang on the end of 
a standard well made supply, and have a pass thru output cable pair that 
gives you both.  I know that sounds odd, but I would put more faith into 
a more common off the shelf robust single output supply and your in-
house made add on than apparently what you chose.  They sound like they 
may be the problem.

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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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