Destructive Testing On SPICE
in [Basics]
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From: Bret Cahill on 29 Jun 2010 10:01 Is there any circuit simulator that accounts for overload and failure of components? Bret Cahill
From: John Larkin on 29 Jun 2010 11:36 On Tue, 29 Jun 2010 07:01:59 -0700 (PDT), Bret Cahill <BretCahill(a)peoplepc.com> wrote: >Is there any circuit simulator that accounts for overload and failure >of components? > > >Bret Cahill > One of the dorkier simulators would put little animated flames over the symbols of parts that dissipated too much power. But that's a gimmick. It's hard for Spice to understand your intent, application, heatsinking, and duty cycles. LT Spice will generate an "efficiency report" which lists power dissipation of various components. John
From: Bret Cahill on 29 Jun 2010 13:53 > >Is there any circuit simulator that accounts for overload and failure > >of components? > > >Bret Cahill > > One of the dorkier simulators would put little animated flames over > the symbols of parts that dissipated too much power. > > But that's a gimmick. It's hard for Spice to understand your intent, > application, heatsinking, and duty cycles. It would have to be set up with inputs for current, wattage or voltage limits. Usually in reliability you have one distribution curve for strength and another for expected loading over the lifetime of a structure. Another much more daunting but related undertaking would be to take the electronics / mechanics analogy much further, i.e., determining the electronic analogues to Coriolis forces, angular momentum, moment of inertia in beam bending, etc. The principle difference is few care if someone burns up a chip but just about everyone cares if an RC building or prestressed concrete overpass comes down. Even that difference fades in power production. A serious attempt at such a project would probably yield a lot of valuable insights and innovations long before it was completed. Instead of using SPICE for simple mechanical impedance problems a generalized application could be used for either. A single click would convert mechanical to electronic and vice versa.. Bret Cahill
From: John Larkin on 29 Jun 2010 16:23 On Tue, 29 Jun 2010 10:53:09 -0700 (PDT), Bret Cahill <BretCahill(a)peoplepc.com> wrote: >> >Is there any circuit simulator that accounts for overload and failure >> >of components? >> >> >Bret Cahill >> >> One of the dorkier simulators would put little animated flames over >> the symbols of parts that dissipated too much power. >> >> But that's a gimmick. It's hard for Spice to understand your intent, >> application, heatsinking, and duty cycles. > >It would have to be set up with inputs for current, wattage or voltage >limits. Usually in reliability you have one distribution curve for >strength and another for expected loading over the lifetime of a >structure. > >Another much more daunting but related undertaking would be to take >the electronics / mechanics analogy much further, i.e., determining >the electronic analogues to Coriolis forces, angular momentum, moment >of inertia in beam bending, etc. Those of us who are electronics design engineers don't work by analogy. We use real facts and hard numbers. There are accepted ways to calculate MTBF of electronic systems, and accepted ways to stress and test actual working hardware. A good EE can design electronics that has multiples longer MTBF than the MIL-HDBK-217 or Bellcore calculations suggest. A bad designer will often come in much, much worse. > >The principle difference is few care if someone burns up a chip but >just about everyone cares if an RC building or prestressed concrete >overpass comes down. Even that difference fades in power production. > >A serious attempt at such a project would probably yield a lot of >valuable insights and innovations long before it was completed. > >Instead of using SPICE for simple mechanical impedance problems a >generalized application could be used for either. > >A single click would convert mechanical to electronic and vice versa.. > None of that last part makes sense to me. John
From: YD on 29 Jun 2010 17:21
Late at night, by candle light, Bret Cahill <BretCahill(a)peoplepc.com> penned this immortal opus: >> >Is there any circuit simulator that accounts for overload and failure >> >of components? >> >> >Bret Cahill >> >> One of the dorkier simulators would put little animated flames over >> the symbols of parts that dissipated too much power. >> >> But that's a gimmick. It's hard for Spice to understand your intent, >> application, heatsinking, and duty cycles. > >It would have to be set up with inputs for current, wattage or voltage >limits. Usually in reliability you have one distribution curve for >strength and another for expected loading over the lifetime of a >structure. > >Another much more daunting but related undertaking would be to take >the electronics / mechanics analogy much further, i.e., determining >the electronic analogues to Coriolis forces, angular momentum, moment >of inertia in beam bending, etc. > That's what analog computers were made for. Convert the mechanical values into their electrical equivalents (analogues), set up the circuitry, let it run and plot the outputs. The operational amplifiers did the mathematics (operations). Nowadays digital computers do it faster with more accuracy. - YD. -- Remove HAT if replying by mail. |