Splitting sync-on-green video signal
in [Design]
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From: mike3 on 9 Jan 2010 15:58 Hi. How could one make an electronic circuit that would split the green signal from a "sync on green" source (like what comes out of some types of computers) into the green, horizontal, and vertical sync components individually?
From: a7yvm109gf5d1 on 9 Jan 2010 16:04 On Jan 9, 3:58 pm, mike3 <mike4...(a)yahoo.com> wrote: > Hi. > > How could one make an electronic circuit that would split the green > signal from a "sync on green" source (like what comes out of some > types of computers) into the green, horizontal, and vertical sync > components individually? http://www.national.com/mpf/LM/LM1881.html#Overview
From: mike3 on 9 Jan 2010 17:09 On Jan 9, 2:04 pm, a7yvm109gf...(a)netzero.com wrote: > On Jan 9, 3:58 pm, mike3 <mike4...(a)yahoo.com> wrote: > > > Hi. > > > How could one make an electronic circuit that would split the green > > signal from a "sync on green" source (like what comes out of some > > types of computers) into the green, horizontal, and vertical sync > > components individually? > > http://www.national.com/mpf/LM/LM1881.html#Overview Hmm. But how about not only extracting the sync but also removing it from the green line to get a pure green signal? In other words, have something where the input is the green+sync, the outputs horizontal and vertical sync and also pure green component (no sync)?
From: John Larkin on 9 Jan 2010 17:26 On Sat, 9 Jan 2010 14:09:44 -0800 (PST), mike3 <mike4ty4(a)yahoo.com> wrote: >On Jan 9, 2:04�pm, a7yvm109gf...(a)netzero.com wrote: >> On Jan 9, 3:58 pm, mike3 <mike4...(a)yahoo.com> wrote: >> >> > Hi. >> >> > How could one make an electronic circuit that would split the green >> > signal from a "sync on green" source (like what comes out of some >> > types of computers) into the green, horizontal, and vertical sync >> > components individually? >> >> http://www.national.com/mpf/LM/LM1881.html#Overview > >Hmm. But how about not only extracting the sync but also removing >it from the green line to get a pure green signal? In other words, >have >something where the input is the green+sync, the outputs horizontal >and vertical sync and also pure green component (no sync)? If you really don't want the sync pulses, the thing to do is clip the negative swing at the "black" level. But why? John
From: who where on 9 Jan 2010 20:55
On Sat, 9 Jan 2010 13:04:34 -0800 (PST), a7yvm109gf5d1(a)netzero.com wrote: >On Jan 9, 3:58 pm, mike3 <mike4...(a)yahoo.com> wrote: >> Hi. >> >> How could one make an electronic circuit that would split the green >> signal from a "sync on green" source (like what comes out of some >> types of computers) into the green, horizontal, and vertical sync >> components individually? > >http://www.national.com/mpf/LM/LM1881.html#Overview oooh, no! That chip is downright evil. [O/T] We used them in an olde (pre-GPS) frequency reference, to extract the sync pulses from rubidium-locked TV transmissions. It gave spurious pulses, and on further investigation this proved to be unavoidable. We switched to the Gennum GS4981 and the problem was history. |