4 Aug
2014
4 Aug
'14
3:35 p.m.
There have been a lot of comments about this thread, all of which I
appreciate.
Here's some more information:
-> There are definitely two pairs of wires going into the coils around
the neck of the CRT. Both of these pairs of wires terminate on the
circuit board that has the deflection amplifiers on it.
That makes it sound like an electormagnetic deflected CRT. This is
entirely possible,, electormagnetic vector dispalys are, perhaps less
commmon than electroictica ones, but certianly not unheard-of
-> The high voltage supply does not appear to have
a flyback
transformer, which, from what I understand in the various comments, is
typically used in a regular raster scan environment.
Technciallly, for there to be a flyback transfoormer, there has to be a
flyback (basically, when the beam is quickly returend form the right hand
edge to the left hand edge of the screen -- the 'flyback' -- there is
energy stoed i nthe yoke and output transformer htat has to go somewhere.
Not surpisingly got get a firly large back EMF which you might as well
step up and use to provide the HV for the CRT, etc (thanks Blumlein).
With a vector display there is no repetifvie motion of the beam, so no
true flyback. No guarantee there will be enough energy stored i nthe
yoike//transforemr to use for the HV. So basically vector displays have
to have an HV supply that is independant of the deflection.
Are there any pins comign otu the side of the CRT neck (other than the HF
connecotr on the flare)? If so, those are pretty mcuh going to be the
delfeciton plates (amongst other things) so it'll be electrostatic.
Incidnetlaly, how many conenctiosn are there to the base of the CRT?
Remember if it's electrostatic, there will have to be 4 for the
deflection plats [1] Two for the heater in all CRTs. So if you only ahve
6 or 7 connecitons , it's not going to be electrostatic, there aren't
enough pins for the electrodes.
Based on what I have read here:
-> If the high voltage for the CRT is generated through use of an
oscillator and diode/capacitor doubler circuitry, then it would probably
be OK to run it without the CRT connected to anything (other than the HV
connector), other than to make sure that the earth grounds for the CRT
are in place to prevent a charge buildup and uncontrolled discharge (the
grounds are in place and secure).
Yes.
-> Since there appears to be no switching aspects to the power supply
(other than possibly as mentioned above for the high potential supply),
running it with no load on the supplies shouldn't cause any damage.
For testing purposes, I will probably fashion some dummy loads out of
automobile lighting bulbs to put some load on the supplies to make sure
that they are regulating properly, and to check ripple levels.
Sure.
-tony