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Old 02-28-2014, 06:07 PM   #20
tom66
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Default Re: How a plasma display panel (PDP) works

Quote:
Originally Posted by JackMiles View Post
Hello Tom66.
In short time i'm planning to build my own pdp panel driver and really i'm out of knowledge. (very dissapointed about panasonic vt60, theres huge mistakes they didnt want to fix) The problem is: sub-fields and scan line+data line selection.
1)I don't ungerstand sub-fields at all) are dispaying subfield with "brighness 1" and then with "brightness 3" gives a brightness 4? How dithering works? Whats the order of subfields? One per line, all lines and again, or all per line and then next line?
2)About line selection: as i see it uses standart signals for making sustain/scan signals, but line selection and data lines for X board are lvds. What format, clock and how many bits it uses?
What oscillograph freq do i need to watch all signals in pdp, 100mhz is enough?
I'm very sorry for my bad english, but please help me if it is possible.
It's an ambitious project, I'll give you that.

The subfields are basically just same brightness levels but displayed for a longer period of time, so for example a subfield of length 1 might be about 1% as bright as one which is displayed 100 times over, each sustain event emits about the same light.

The line selection is logic level from control board, ground referenced. At the buffers, it is VFG referenced, that is the sustain node (without the Vsc applied.) This requires optoisolation.

Driving IGBTs at the required rate (around 200kHz) is a high level power electronics project. I would not be surprised if the first few boards work for some small amount of time before catastrophically failing. For learning experience, I would try experimenting with a different panel... maybe one not so valuable

A common sustain driver (SS) is a lot less ambitious than the addressed sustain driver.

Scope: minimum 100MHz digital scope like Rigol DS1074Z, DS2072A, Agilent 2000X, etc. You need the high waveform update rate to see the most detail.
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