12-09-2020, 06:52 PM
Great result Jeffrey that's looking very promising. Good to hear the H lock is working well. I know you will sort out the V lock.
In the case of my attempt. Using the TVP5150 each line lasts exactly exactly 864 cycles. So the field will free run at the correct frequency.
I just needed a way to detect the transition from even to odd field to reset the counters.
I did this by counting the 10uS(approx) pulses that separate the broad pulses.
At the beginning of the even field there are 7 pulses between the broad pulses. At the beginning of the odd field there are 7 pulses between the broad pulses but there is also an 8th after the last broad pulse.
So if I counted 7 pulses I knew it was an even field or if it was 8 pulses it was an odd field. Any other number of pulses were ignored and the frame would free run.
If the CV2000 has just one field pulse this would be of no use.
Frank
In the case of my attempt. Using the TVP5150 each line lasts exactly exactly 864 cycles. So the field will free run at the correct frequency.
I just needed a way to detect the transition from even to odd field to reset the counters.
I did this by counting the 10uS(approx) pulses that separate the broad pulses.
At the beginning of the even field there are 7 pulses between the broad pulses. At the beginning of the odd field there are 7 pulses between the broad pulses but there is also an 8th after the last broad pulse.
So if I counted 7 pulses I knew it was an even field or if it was 8 pulses it was an odd field. Any other number of pulses were ignored and the frame would free run.
If the CV2000 has just one field pulse this would be of no use.
Frank
