Quasi-interesting CRT puzzler

Thanks everyone for all the good suggestions and links.

If I can't get the power amps and Z-axis stuff to work, there's a building full of old arcade machines for sale down the pike. Not to mention the occasional CAD/CAM vector monitor on eBay once in a while.

Why don't they use ELECTROSTATIC defelction?

Mark

Because the CRT is generally small, very long and dim.

Graham H

How about a class-D amplifier? Besides, 60 screen updates per second is not enough for a computer monitor. You'll need at least 70Hz.

In message , dated Thu, 17 Aug 2006, Mark writes

There aren't any ESD tubes made. Chicken and egg.

HP must have had some made up, long ago, for their 13xx series of monitors.

But in general electrostatic deflection isnt popular in the larger screen sizes, as the tube gets too long-- apparently it's hard to get much of a deflection angle electrostatically without defocusing the spot too much.

In message , dated Thu, 17 Aug 2006, Ancient_Hacker writes

That can be fixed. But the resulting tube is complex and costly.

Can't be arsed to look through the whole thread to see if someone else has come up with this. Just a WAG anyway. Since fast vectors mean a high di/dt and consequently slow vectors a proportionally lower di/dt it would seem you could use that for the Z modulation. Just find somewhere to take it off the signal path before the coil drivers. Of course, you'll need to use the abs() value.

- YD.

Ouch, 3 kW peaks. Ok, average may be a lot less but better use it only on cold nights. Have you tried to find out how the Asteroids game does it? Must be something a lot more efficient.

- YD.

Yeah. So, if you're going to do that, then take the yoke off and cut the windings off it. But keep the form, of course. Following the winding pattern of the old coils, wind about 20-30 turns of #18 or so for each coil, symmetrically, and slap it on the tube, pass a couple amps through it, and see what you get.

Oh, wait. Before you tear the yoke apart, measure the DC resistance and inductance of the windings, and duplicate that (4 coils) and plug them in in place of the yoke, so the Hor. osc. will work and you get HV. :-)

Or, just make a new form, wind as above, and plug the old yoke back in. :-)

Good Luck! Rich

rectify the X and Y rate square them. add the squares and take the root of that. (this is pythagoras' theorem.)

if that's too hard rectify the rates,and add 1/3 of the lesser to the greater it'll be almost right. (+/- 5%)

Bye. Jasen

add a second winding to both x and y, feed both through bridge rectifiers and then hook em in series.

In the Mid '70's i worked on radar consoles about 20" that could do TV raster, normal radar scan, spiral scan, and paint a bunch of randomly placed symbols and text. It was electrostatically deflected with 2200 V transistorized amplifiers; three transistor totem poles each side.

The schematics for the Atari games are at:

kevin