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Subject: Re: [Homebrew_PCBs] OT PCB Mounting loads

From: Steve Greenfield <alienrelics@...>
Date: 2002-06-02

I don't think this is OT.

I think it really depends a -lot- on the solder used, how it was
soldered, etc. NASA and anything for the military gets tested to
death in vibration and G-force testing. Anything automotive gets
similar testing at a much lower level. Poor solder joints that will
last years in a small circuit on your test bench may last a day in
a car or a pinball game.

How many G's a board can take is going to depend a lot on how it is
supported. Same with vibration. Anything that sticks up high from
the board is going to be more susceptable to damage.

I think an important part of this is going to be isolating the
shock of the charge from the boards. I've seen wiring get
overlooked- short straight segments of solid wire are going to
transfer shock a lot more than very slack sections of very flexible
stranded wire. Test lead wire is meant to take a lot of bending
without breaking.

Steve Greenfield

--- Dave King <KingDWS@...> wrote:
> Hi
>
> This is a bit of a strange question. I keep stumbling into
> strange (but
> interesting)
> projects to play with.
>
> What is the maximum vibration level and/or G force standard smt
> or thruhole
> will tolerate ?
>
> I've been asked if I could figure out a electronic detonator for
> an
> airburst charge
> for snow guns. These are the guns/mortars they use to fire 4-8lb
> charges at
> potential slides to trigger them. The trigger will be a pic that
> simply counts
> and then fires a electric match after the preset delay.
>
> I'm hoping this will prove tremendously difficult so I get to
> "work" and
> have to blow
> things up all winter ;-]
>
> Tia
>
> Dave



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