Groups > sci.electronics.design > #518149

Re: Abusing brick on the rope

From	piglet <erichpwagner@hotmail.com>
Newsgroups	sci.electronics.design
Subject	Re: Abusing brick on the rope
Date	2018-10-02 21:25 +0100
Organization	A noiseless patient Spider
Message-ID	<pp0k8u$6t0$1@dont-email.me> (permalink)
References	<9d99359d-4f4d-444e-b3e9-6e4dca24a80f@googlegroups.com>

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On 02/10/2018 20:55, 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.)
> 

I have seen a LED become dim after being exposed to episodes of reverse 
polarity. In the case I saw it was spikes of 18-30V (so well above the 
5V usually seen for Vr on LED datasheets). The first few zaps seemed to 
have no effect but damage must have built up.

If that is a SMPS then 120V 60Hz appearing on the output seems unlikely 
but if an output rectifier shorts then spikes of reverse HV at the 
switching frequency could explain what you saw?

piglet

Thread

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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