[photo-3d] Re Viewer illumination

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

Sorry for the late reply to this post but my E mail has been out of action
for a while, E R Swanson wrote.

>
>Some time ago I posted my version of the cold cathode illumination setup
>for a full frame viewer. It's suitable for most of the wooden box viewers
>that have been home made or commercially sold, and will work great on the
>Comby on similar viewers. The great thing is that you can build them
>yourself in an hour or two for about $45 using nothing more sophisticated
>than a hot glue gun, a little superglue, and a Dremel tool. Because the
>illumination stage is cold cathode, it has an extremely low power draw,
>low heat, and long battery life running on 4 AA batteries. Using a sawed
>up plastic WalMart shower mirror, it reflects the tube and gives you the
>effect of having a bunch of illumination tubes. I posted the info to the
>list once, so the details should be in the p3d archive. (I can't claim
>credit for originating the cold cathode approach, but I can't remember who
>first came up with it, alas...)

I seem to have missed the previous posts on cold cathode illumination or I
would have replied before. Do you actualy mean cold cathode or just "cold"
light fluorescent tubes, because as I understand them cold cathode devices
are at least potentialy sources of X rays and are not much used now for
that reason. Without either direct or indirect heating of the cathode the
potential applied has to be sufficient to strip electrons out of their
orbits, but they then have sufficient energy to generate X rays at the
anode, but would probably draw less power as you say. With heating there is
thermionic emission of electrons from there orbits after which a much lower
potential is sufficient to accelerate to the anode without generating X
rays on collision, but overal there would probaly be more power draw
because of the heating,again as you say. However it does not seem to be a
good idea to use a potential X ray source especialy as it is going to used
close to the face and eyes. P.J.Homer