Small CRT Monitor Driver

[MadMan]

Bear with me here, I don't know all the theory behind TV operation, just basics.

So a friend of mine has cajoled me into figuring out the electronics part of a project of his. He's a total nerd and he wants to make a Pip Boy with an actual crt screen.

Basically, we need something to drive a 5" monochrome crt monitor. Has to be solid state, composite/rca video input, in a relatively small package/pcb, and preferably something simple enough that I can build/assemble myself with relative ease, or already available finished product.

Now I have a 5" crt from a b&w portable tv, electromagnetic deflection, pretty typical. I picked a particular crt because it was really short, less than 5 inches. Now, the control board of the tv works, but it's awfully big, about 8"x5".

The thing is, everyone has a fetish for oscilloscope clocks, so there are a few available options... but they're for electrostatic deflection and those pretty much are used for vector displays, not video. Plus everyone also likes using surface mount microscopic components, which would require me to git gud, as well as bother my other friend who's got the soldering equipment for that. Bah.

In my googling, I found this: http://www.electronixandmore.com/projects/tvtoscope/ Which shows promise. I figure, if I add transistors to the x and y outputs, to step them up, I could just hook them up to the yoke. Boom, deflection. And the z-axis (I think) I could hook up to the grid of the crt. Then power the filament, the cathode, and the HV. And it'd be a tv, right? Well, monitor.

Of course I know it's not quite so simple. The HV is modulated, isn't it? So keeping it just on all the time is probably not right... right? And then other things.

Thoughts?

Yes, I already know I'm a masochist.

[jr_tech]

Perhaps the flat tube and guts from a Sony Watchman?

http://www.videokarma.org/showthread.php?t=246309


jr

[MadMan]

Originally Posted by jr_tech

Perhaps the flat tube and guts from a Sony Watchman?

That would be cool, and I have one, but it's not quite the same I'm afraid...

[maxhifi]

My suggestion, is to take more or less everything from one of those 5" portable TVs and repackage it. Many of the later ones had a composite input already. Way too many special parts needed to try and design this from scratch.

[MadMan]

Originally Posted by maxhifi

Way too many special parts needed to try and design this from scratch.

Well, I mean, my initial plan was to find a schematic and duplicate the essential bits on a bread board, possibly using the original components. So basically repackaging it. But then I realized this tv is a cheap Chinese turd and the only way I'd get a schematic is if I drew one myself. Which I probably could, but honestly I feel like building something from scratch would be easier.

[Electronic M]

Have you considered a viewfinder from a video camera? Depending on the vintage and application, screen sizes from 1" to 5" were made. Most used compact stripped down boards that had only the essential circuits to act as a video monitor. If you can find one that uses the same deflection angle and HV as your target CRT, then that could serve as a near plug and play monitor board. Pair that up with a Raspberry Pi, power source, some programming and a well made case and your pretty much there.

[centralradio]

I agree with ElectronicM.There is still plenty of old camcorders around at fleamarkets ,tag sales and goodwill. I like the AN25XX series chip which is in many camcorder viewfinders. A workhorse of that era of camcorder viewfinders in Matsushita /Panasonic built camcorders.And probably some others too.

Google image search AN2510s.

https://www.google.com/search?q=an25...w=1344&bih=677

[MadMan]

That's a very interesting idea, I could maybe modify the control board for a viewfinder crt.

Also, that feel when my Pinkie Pie avatar shows up about 30 rows down in that google image search :P

[dr.ido]

Another option may be the CRT and and electronics from one of those intercoms with the camera usually used for viewing who was at the door. Before LCDs got cheap these used knock offs of watchman style CRTs. I picked up a couple a while a go to play with a flat CRT without butchering a watchman. I never did end up doing anything with them.