Re: A question about UV and homemade plasma globes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Bob (R.A.) Jones" <a1accounting-at-bellsouth-dot-net> 

Original poster: "David Speck" <dave-at-davidspeckmd-dot-org>

 > into a can to collect the oil drippings to avoid a slippery mess in your
shop.
 > Also, put some sort of shutoff valve in the vacuum side of the pump, in
 > case you lose or shut off power while there is a vacuum in your test
 > chamber.  Otherwise, the vacuum will fill your chamber with oil from the
 > compressor.
 > I don't know or a way to get the oil back into the compressor, so
 > eventually, the unit will fail due to loss of lubrication.   (In normal
 > operation, it's a closed system, so the oil is never lost or
 > contaminated.)  I believe that the cavity of the motor housing is open to
 > the intake side of the system, so it might be possible just to pour the
oil
 > (after you filter the dirt out of it) back into the inlet side of the
pump,
 > but I've never tried this.  Might be worth it to take apart a dead unit
 > just to find out, but I've never had time to try it.
 >

On the unit I cut open the vacuum inlet  was open to the cavity.
So yes you can pour oil back in. If the inlet is at the top there is no
chance of sucking up the oil.
But the shut off valve is a good idea anyway.
The main problem is the units I have used overheat and fail.  probably
because the motor is not designed to run in a vacuum.
Not a big  problem just don't run it for long periods.
You can easily get down to a vacuum level for diffuse discharges.
I have seen two in series is recommended.  The second unit helps to keep the
oil degassed/dewatered in the first unit so you get a better vacuum.
There may be serious safety issues in doing that if the pressure can build
up in the second unit for some reason.

Try carefully cutting open the evacuation tube of a florescent light so as
to leave sufficient tube to connect to a rubber hose.
What's left of the phosphor material can be removed with dilute hydrochloric
acid if you want a clear tube. Its tricky getting the acid in and out and
rinsing .
But you end up with a nice discharge tube with built in electrodes.

Bob