Hi Darron,

If I recall correctly, these systems work by having a medium voltage supply
connected across the bulb and then EITHER a separate trigger electrode OR a
some kind of coupling (like a transformer) in series with the medium
voltage supply to be able to introduce a firing pulse. My guess would be
that this trigger pulse is not happening or is not being coupled properly.
Does the bulb have two or three terminals?

Sean


On Wed, Jan 24, 2018 at 1:56 PM, Darron Black <darron@griffin.net> wrote:

> I've got a xenon flash system providing the light for a flying image
> capture of components on a pick and place machine.  Here's the datasheet
> (MVS-7020-04) http://www.visionlighttech.com/sap/datasheets/302-7020-
> 10.pdf
>
> Lately, it's taken to missing strobes.  The pick and place was not
> designed to handle missed strobes, and when that happens it throws away
> ALL the parts on the head at the time.
>
> I figured it was the bulb at first, and a brand new bulb appeared to
> help for a bit... but it's back to failing again.  I've replaced the
> bulb a second time with very little improvement.
>
> Since the xenon flash system is about ~16 years old... I figure some
> capacitors may need replacing.
>
>
> So far, I've really only got as far as the big capacitor attached to the
> bulb itself.  It's 12uF +/- 10% nominal, and two different meter
> readings put it at 13.4 and 13.6 uF.  It's of this type:
> https://chicagocondenser.com/cmp/
>
> It uses "polyester resin film and the finest grade Kraft paper
> impregnated with mineral oil" (or silicone dielectric fluid, it's not
> clear which)
>
> Can this capacitor actually GAIN capacitance as it ages?
>
>
> I don't really see a safe way to measure this system while active to see
> what's going on.  It's pretty high voltage, and then there's the
> blinding levels of light output.  It's got a door interlock to make sure
> you don't do something stupid like try to run it open... so I haven't.
>
>
> Any other suggestions?   Does anyone else know of another common failure
> mode for flash systems?  The system is difficult to disassemble (or
> reassemble, rather), so I'm starting with this cap.
>
>
> Darron
>
> darron@griffin.net
>
>
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