smeezekitty wrote:Yeah it is. I still wonder what happened. It might motivate me to tackle working on a viewer program again at least.
Very sorry to loose Gary here...hope he's doing well up in the southern highlands of NSW, he was a mechanical television Sensei and like you able to turn that into software as well ....
I think he's software is scattered about but not in one place here on the forum ...Since the web site is gone we should put it on a page here ..there's a bit of NBTV software about The big picture viewer served us well ..
A multi system viewer would be great there's few that can do this so it would be a good thing ....i am a big fan of FreeNBTV a viewer would top it off !
Already ahead of you. The original design camera and monitor are already completely enclosed in wooden boxes. I can put black tape over any gaps if I find them. My dad helped me build the boxes when I first made them at like 12 yo. Good decision in retrospect.
This is a good skill to have a pat on the back for your dad .
The aperture size for a disc is formidably small. I'm using a 12" record (so ~306mm) and even the 1mm holes I'm using are oversized.
Well its had to get the correct Aperture size on a cd size bit easier record size but possible close enough to still get it to work ...
I used paper encoder printed out and stuck on my cd nipkow so it was a reflective method IR led sensor to make the mechanical sync and for motor control ..the wobble of the disk was very very small but enough to vary the sync pulse ....the wobble was due to the mount to motor shaft it didn't have to be that accurate for what it was made for but not so good a flaw for a mechanical camera design ...The video head and mount are dead on made it not to wobble so you should have better luck more accurate sync pulses with correct pulse widths one after the other ..the encoder disk holes what ever you use have to be accurate or image will be flawed ..
I'd much rather keep them separate units. It feels like cheating to have them on the same shaft. Besides, that is a lot more difficult mechanically and mechanical design is my weakest.
Yes its not my thing either agree here .
I am surprised you got this much bandwidth the the photoresistor. My tests showed a very poor response. Surface area isn't a problem though. When I say a large CDS cell, I mean a LARGE CDS cell.
I only used it at the start of the flying spot idea and gave up on them but they are yes sluggish solar cells are much better idea .
It is the same as the big one in
this picture. It is at least 20mm wide.
But maybe that's why the response is so bad. It probably has a lot of capacitance being so large.[/quote]
More than likely worse bigger they get but as you know better light sensitive devices out there .
I read all the linked threads completely. What a rabbit hole! Looks like I'll have a lot of pain with synchronization and noise. I'm not nearly as picky as Gary was though.
I was honestly tempted just to free run the motor around the right speed and hopefully create sync pulses that are good enough for a stable picture. My disc is large enough and is decoupled from the motor by a belt so that there is little speed variation over the course of one frame. My mechanical monitor only syncs once per frame and it works well.
Funny enough you can get pretty close to correct speed free running but it will always drift above or below wanted set point ...if 32 line 400hz i used that free soundcard scope1.32 program on the below screen to view the sync and checking how well the motor is controlling speed .
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Really need good motor control as it will go out of sync and be very annoying ! pain to record too ....view the speed on that software feed the sync to the sound card and if it is stable fine .
Apparently my disc is quite thick for a camera but I don't think there is much I can do about that.
harder to wobble i like that !
It does seem like flying spot cameras are easier to build but they have their own uniqe challenges. Like finding a bright enough light source that won't overheat the disc. Also, it's a bit annoying that they require total darkness. If it doesn't work out with a sensor behind the disc, I might try it.
I made my flying spot camera with one luxeon and the thing was not even enclosed wasting light causing noise i still manage to get an image ...if you read the first link on the flying spot camera i started with a out with the luxeon torch then switched to a out of focus green laser behind the nipkow till i broke it ! then back to the luxeon
http://www.taswegian.com/NBTV/forum/vie ... &start=135So heat is not a problem just most people tended to use a converted slide projector i had other ideas .
Lots of good amp circuits in the threads linked. BC109's are not easy to get in America. But I think I can substitute in 2N5088's. They have similar Hfe and noise figures. Somewhat lower current but I shouldn't need to run a lot of current through them anyway.
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Yes lots of head amp circuits lots of trany versions i like the ne5534 the trany circuits can be touchy to get right but fun to experiment and see what works for you .