Re: New Vector monitor project progress

On Thu, 14 Oct 1999 15:41:58 -0400, you wrote:

>Here is the latest thinking on the New Vector monitor project.
>
>Generating high voltage will pose no major technical challenge as it is
>essentially similar to non-vector systems but needs it's own oscillator and
>drive.

No problem. (Though without the inductive kick of the raster yoke, you
will need to drive the HV flyback of the raster monitor with a higher
voltage than the raster circuit does. The raster circuits work right
around the rectified line voltages (140v or so). You'll have to come
up with some type of voltage multiplying circuit that can delivery
some relatively high currents. Certainly not undoable!)
>
>The Z (R G & B) inputs require simple signal conditioning with spot killer
>and overdrive protection.

Piece of cake!
>
>The linear Yoke drive will be simple to fabricate from scratch.
>

Try to do a better job than the monitor manufacturers did! It'd be
nice if these things lasted a while without being a fire hazard!

>Now what you've been waiting for: The Yoke!
>
>I have been thinking about this for years. I don't want to wind my own, but
>you have to to get the correct inductance for the Y axis. It is about 100x
>too much inductance, and would require a high voltage drive to make it work
>without re-winding. Inductance goes as N^2 where N is # of turns. So
>divide the coil up into 4, 8 or 10 sections and run them parallel. That
>will give me 1/16 , 1/64or 1/100 the inductance, which will be between 1- 6
>millihenrys. This will be adequate for use with a moderately higher voltage
>drive.

Brilliant. It'll be interesting to see how well this converges. By
putting them in parallel you can lower the voltage of the drive, but
buy putting them in parallel you're also going to need *much* higher
drive currents than a single properly wound yoke. No problem, just
throw a couple more pass transistors at it.

(Of course after you've divided the yoke up into 4, 8 or 10 sections,
maybe you could throw away 3, 7, or 9 sections? And just drive the
yoke with the proper amount of turns? But I'm sure you've thought of
the pros and cons of this, and anyhow, how you do it is up to you!)

>Now, if someone can direct me to where to get complete chassis that are new
>for under $200, then we are in luck, otherwise, I will have to go to the
>local department store and use a new TV which is less expensive, but no nice
>metal chassis. My main concern is that whatever chassis I pick I can get
>many of in case everyone wants to buy a kit. (Clay)

How much does a standard WG raster cost? Just buy whatever you need,
if you can build brand new Vector Monitors for under $250, that
perform as well, or better than the old ones, you'll get your
development costs back.

>Any arguments for 25" -vs- 19"? Don't most vector machines have 19" in the
>first place? Tempest does. What did Star Wars have? I want to set up my
>Star Wars.

25" Amplifone. (Medium res?)

>OK, Please comment and complain about how I can't do it.

No one ever said it couldn't be done, it's your $250 claim that I for
one am doubtful of.

If you build a new vector monitor for $250, or even a $50 kit for a
$200 monitor / $200 TV / $200 Washing Machine / $200 Golf cart / $200
or whatever, that turns it into a vector monitor, you will have no
problem selling them.

So just get on with it! No need to keep asking permission, just build
them and they will buy!

I'm probably going to want a half a dozen, just let me know when
they're ready. (I'll start with one, and depending upon how well it
works, I'll order the rest.)

-Zonn
Received on Thu Oct 14 15:25:53 1999