View Single Post
  #8   Report Post  
Posted to sci.electronics.repair
N_Cook N_Cook is offline
external usenet poster
 
Posts: 5,247
Default Function of component in flash tube trigger circuit?

James Sweet wrote in message
news:ArnRj.637$PY5.15@trnddc01...



What seems strange is this transformer must be half or third of the

volume
of the ones in compact camera flashes but the tube is perhaps 100x the
volume of the tube in one of those cameras (1cm diameter, 20cm long).
Don't
know the joules rating of this one, a large studio flash unit, but 530V
standing voltage. Perhaps 2m of wire wrapped around the flash tube, as
trigger, all in all seems inadequtely tiny in comparison.

I think I'll try 2 camera ones in series with 100 ohms initially to try
and
localise why not triggering. I may try subbing this tiny stepup
transformer
with one 3 times the size from a compact camera, as am wondering if it
could
be internally arcing actoss turns.



The size is virtually irrelevant, as Sam says, almost no current is
required. I've used a tiny trigger transformer salvaged from a disposable
camera to trigger a huge (about 8" long) 1KJ flash tube. Some are bigger,
some are smaller, it has more to do with age, manufacturing process, and

the
need for compactness.



Is it possible to have a non-functional tube with no signs of problems ,
like the black patches on the ends of a fluourescent tube that is on the way
out.

This one looks perfect other than the glass is a bit dirty on the outside,
because the distributed trigger stops any cleaning. Not been dropped, no
cracked glass, no odd looking deposits on the elctrodes or on the inside of
the glass.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/