Wednesday, July 19, 2006

TWIN H.V. cable burnt

In the afternoon, the TWIN excimer amplifier suddenly stopped firing after running for half hour. I found the power supply light became red, the light was off after pressing the reset button. Then I pushed the H.V. button and Laser button, I heard a buzz sound inside the excimer chamber. I energized gradually to the amplifier, the voltage reached 12 kV, the buzz appeared again then the system shut down immediately.

I opened the chamber, and turn on the system to check where the buzz came from. I found the high voltage cable was burn, the buzz was from the broken cable. The arcing from the cable caused the fail in high voltage increasement.


Jozsef said...

we have 2 possible solutions to fix your problem.

You can cut down the broken part, and connect the shortened cable to the
old position (noise filter). For that you may also need to shorten the
hull of the high voltage cable (the black, ripped cable channel between
the laser housing and the power supply) of about 30 cm. We can provide
you detailed assembling instruction for that. This would be fast and the
assembling is also not very complicated, but only a possible way if you
have the 30 cm reserve length between power supply and laser body
(eventually need to be placed closer, perhaps not, it should be checked).

Second solution is that we ship you a spare cable. In this case you have
to wait several days for delivery, and than replace the old one. If you
choose this solution we need to know the full length of the cable, from
the connection in the power supply up to the connection to the noise
filter inside the laser. For measuring that you should remove the cable
from the hull and measure the correct length (it is anyway necessary to
remove it when you replace it). We would like to know the full length of
the cable and the length of the free standing part (the second one is
practically the distance between laser housing and the noise filter
inside the laser, this is the part where the outer, grounding part is
already removed and connected to the laser housing). You can pull out
the high voltage cable out of the black hull from the pover supply side.

If you prefere solution one please let us know and we provide you the
assembling informations.
If you choose solution 2 please let us know the correct cable lengths.

Thank you in advance.

Best regards


Jozsef said...

Our suggestion is, that you cut out the damaged part of the cable and
join the remaining two parts by soldering. In this case you only need to
pull the cable about 15 cm inside the laser. Eventually, you may not
even need to shorten the shell hose in this case, you will see.

For solderind the damaged part first you have to remove the outer
shielding mesh on a length of about 15 cm. Form a grounding cable out of
that. Do not cut it down, but you can shorten it if necessary. Please
also take care not to damage the insulator of the inner part and also do
as few damage in the mesh as possible. Important is, that you have about
15 cm cable length between the soldered point and the meshed part (mesh
is the ground, cable is high voltage!)
By soldering, the connection should have a low resistance, e.g. you can
overlap the two cable parts and solder them together that way.
After that you can pull back the insolator tube and connect the cable
again (dont forget to connect the ground to the housing).