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garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
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| Posted: Sun Dec 20, 2020 3:37 pm Post subject: |
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Hah!!! I had never heard about the RBG connection...
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jask
Joined: 17 Mar 2006
Posts: 10187
Location: kamloops BC
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| Posted: Tue Dec 22, 2020 7:51 am Post subject: |
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crazy eh?
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Zebra
Joined: 02 Jul 2020
Posts: 93
Location: NJ USA
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| Posted: Fri Dec 25, 2020 3:34 am Post subject: |
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| gjaky wrote: | | Zebra wrote: | | garyfritz wrote: | Google "calligraphic CRT projector" and you'll find a number of articles and papers. Might still make your head explode.  |
I did and it did...
I didn't find anything helpful for explaining what it meant in terms of Barco's flight sim crt projectors that use more power than a small star though. |
The power consumption is mostly coming from the deflection circuits. In a raster scanning CRT display the horizontal scan is usualy done by a resonant flyback circuit which is rather efficient. Still if the scanning frequency is high the deflection coils can take up several hundred Watts of power. Vertical deflection is less demanding as the scanning frequency is not so high, sometimes low power (~20W) audio amplifier ICs are used for such purpose.
In a calligraphic display you want full control over both vertical and horizontal deflection this only can be done with linear amplifiers, which are nowhere near as efficient as a flyback circuits, plus you have now the same speed requirement for the deflection for both planes. |
It seems like it's beyond something that's just inefficient compared to the norm. The sort of power that this Barco requires is similar to my 5.6kw spindle motor. It's not a case of an extra 100 watts either way.
It's the only projector I have seen for the American market that can not run from a regular 120v outlet aside from some of the larger theater projectors with 11kw Xenon lamps.
My guess would be that it's a lot brighter than a regular 1209. Does a regular 1209 require a 240v 20a supply?
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Zebra
Joined: 02 Jul 2020
Posts: 93
Location: NJ USA
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| Posted: Fri Dec 25, 2020 3:38 am Post subject: |
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| Curt Palme wrote: | Simple.. no scanning lines. Back in the 80s there was a video game where your plane shot at shooting stars. It was done via a vector display, and at the time it was the sharpest looking image out there. BAck then I had no idea why until I got into the CRT thing, and someone explained it to me.
There was a company also manufacturing a vector planetarium display that I saw about 15 years ago. Same thing, no scanning lines, no raster, and CRT tubes that were absolutely stupidly expensive. |
Ok so it does mean it's like a vector arcade monitor.
As they describe it as "raster calligraphic" then I would assume it can be used for both raster and vector. If this is the case that would make it the best retro gaming projector ever.
Vector arcade monitors have gotten very hard to find these days so I'm sure some of the fans of early 80's games would be interested in that.
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gjaky
Joined: 05 Jun 2010
Posts: 2802
Location: Budapest, Hungary
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| Posted: Sat Dec 26, 2020 9:07 pm Post subject: |
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| Zebra wrote: | | gjaky wrote: | | Zebra wrote: | | garyfritz wrote: | | Google "calligraphic CRT projector" and you'll find a number of articles and papers. Might still make your head explode. |
I did and it did...
I didn't find anything helpful for explaining what it meant in terms of Barco's flight sim crt projectors that use more power than a small star though. |
The power consumption is mostly coming from the deflection circuits. In a raster scanning CRT display the horizontal scan is usualy done by a resonant flyback circuit which is rather efficient. Still if the scanning frequency is high the deflection coils can take up several hundred Watts of power. Vertical deflection is less demanding as the scanning frequency is not so high, sometimes low power (~20W) audio amplifier ICs are used for such purpose.
In a calligraphic display you want full control over both vertical and horizontal deflection this only can be done with linear amplifiers, which are nowhere near as efficient as a flyback circuits, plus you have now the same speed requirement for the deflection for both planes. |
It seems like it's beyond something that's just inefficient compared to the norm. The sort of power that this Barco requires is similar to my 5.6kw spindle motor. It's not a case of an extra 100 watts either way.
It's the only projector I have seen for the American market that can not run from a regular 120v outlet aside from some of the larger theater projectors with 11kw Xenon lamps.
My guess would be that it's a lot brighter than a regular 1209. Does a regular 1209 require a 240v 20a supply? |
I've once seen pictures from the inside of such projector, it was indeed full with power transistors.
I would not think much more brightness out of that chassis since it uses the same tubes as normal 1209, and therefore limited by the tubes themselves (cathode current compliance, x-ray emission considerations etc.)
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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Zebra
Joined: 02 Jul 2020
Posts: 93
Location: NJ USA
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| Posted: Sun Dec 27, 2020 7:34 pm Post subject: |
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I don't know if the rastor calligraphic models use the same tubes as a regular Barco 1209, or if a regular 1209 was already maxed out on tube brightness. I do know that you don't use 8x more power for no reason though.
The 7120a and the 1209 can't be exactly the same inside as some changes would be necessary to add the vector capability.
The logical / deductive reasoning part of my brain says that the only reason to make an otherwise similar projector use a lot more power would be more brightness. More power on other projectors always = more brightness.
I would also guess that Barco limited brightness on a regular 1209 to extend tube life (and make them work on regular domestic power outlets). It's possible that a government / military flight sim user would require good performance in a more brightly lit environment. They would also have the cash and technical support to deal with more regular tube replacements and higher voltage.
The one (and only) thing government is good at is wasting our money.... Replacing tubes every 1500 hours is nothing for them...
This document was a good bit more helpful than Barco's regular marketing blurb on it's rastor calligraphic line. Check out page 18.
https://www.manualslib.com/manual/213851/Barco-Seer.html?page=18#manual
It makes it sound like it's capable of displaying both rastor and vector images at the same time. The raster image being the video feed for the flight sim (I.e. the background scenery). The vector image is then displayed over it for grid lines and crosshairs and all the other military flight sim-like content that requires straight lines or precise coordinates.
It says the calligraphic image is 2-3 x brighter than the rastor image. This is obviously necessary or you wouldn't be able to see it clearly with both onscreen together. It's almost like two projector back ends in one, which would be one explanation for the extra power.
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