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Re: Mirror Camera project

PostPosted: Tue Jul 01, 2014 10:45 pm
by Steve Anderson
Harry, sit down and take a deep breath...tell you what...have a beer...on me...

I will admit as much as I visit this forum at least once a day I haven't been keeping up with this thread in detail.

It would seem you're fighting a war on several fronts, those that have had to do it, well, hats off. But here there is no reason to do so in this case.

Break the project down into sub-sections and deal with one at a time...don't get distracted by the other (future / in the pipeline) chunks.

My thinking...get the electronics sorted first, for me the easier part. Get it stable and DO NOT rely on that old dubious published stuff which specifies anything like a BC109C...it's 40 years out of date and can be accomplished so much easier these days.

Analyze, examine, inspect, survey, study, scrutinize and boil-down the results of each progressive step.

DO NOT be disheartened. Those at Bletchly Park were not.

Steve A.

Re: Mirror Camera project

PostPosted: Wed Jul 02, 2014 1:44 am
by Harry Dalek
Steve Anderson wrote:Harry, sit down and take a deep breath...tell you what...have a beer...on me...


Hi Steve

Yep i am having a relax and pondering how these 2 mirrors are going to do my bidding directed to my light sensor. . :twisted:

I will admit as much as I visit this forum at least once a day I haven't been keeping up with this thread in detail.


Thats ok haven't missed much yet bit of a trial and error , try this whoops try again :wink:

It would seem you're fighting a war on several fronts, those that have had to do it, well, hats off. But here there is no reason to do so in this case.


Yes i suppose the optics i have said before i am not good at and some thing not really explained well in similar passed projects Nipkows yes but mirror drums its a little less so.
The head amp and type of light sensor is some thing i have jumped about with mainly as i can tell if theres enough light or not or the mirror scan to it correct ,reason i would like to try Garys idea of using an LED to see that in reverse if it does a raster scan .

Break the project down into sub-sections and deal with one at a time...don't get distracted by the other (future / in the pipeline) chunks.


I know your right thats a standard procedure way or doing things ,this ones a little different to other things i have tried so it intrigues me .

My thinking...get the electronics sorted first, for me the easier part. Get it stable and DO NOT rely on that old dubious published stuff which specifies anything like a BC109C...it's 40 years out of date and can be accomplished so much easier these days.


Will not be to many more of them i have run out of the BC NPN version as you say ,Is there a IC version about ?

Analyze, examine, inspect, survey, study, scrutinize and boil-down the results of each progressive step.


Well i had been thinking i need ways to test what i can't see ........with a monitor you can see with your eyes how far or close you are as the scan lines first need to been seen as a raster modulate the light you can see if you scan line frequency is right so on....the mechanical camera with out a monitor on the same mechanical system is a bit harder, i can only see trying some things in reverse will test the mechanical side of things as working .
Garys software shows me a my raster is there at 400 hz ....so the line frequency is ok so master oscillator enocoder bistable motor control side of things.
So i am looking into stuff i have not tested fully such as video mixer and or its bandwidth.
Could also be still the laptop i will see this if i play a correct nbtv wav file signal via the mixer to the lap top to monitor .
I will take your advice and make sure the electronics side of it is ok .

DO NOT be disheartened. Those at Bletchly Park were not.

Steve A.
[/quote]

Its a little frustrating but worth the work if i can get it working ...No worries Steve Thanks i will keep at it :)

Re: Mirror Camera project

PostPosted: Thu Jul 03, 2014 3:32 pm
by Harry Dalek
OK next few posts will be tests .

Steve you are right in that i need to track down problems one at a time and find out what is or isn't working .

I think the best place to start is my monitor which is the lap top if thats a problem i would be going no where fast .

The test i have done today is pretty simple i am hooking up my Samsung phone which has NBTV wav files on and i will play these to the lap tops line input and see if theres a problem inputting audio video to the laptop using Gary's little NBTV program to display.

Results were fine some results posted below the lap top played the live sound fine .

So i can cross that off the list , i will move onto the camera next .

Re: Mirror Camera project

PostPosted: Thu Jul 03, 2014 4:49 pm
by Harry Dalek
Well i had some time today to do the second test .

This time i am testing the video sync mixer ,test is similar to the last but the video sync mixer is between the phone and the laptop displaying .

I am using the club handbook mixer in my project and only has 2 controls brightness and gamma both worked ,i have the sync from my circuit off while testing as the video has sync .

Results below .
Looks like i can cross this one off my list as well.

Re: Mirror Camera project

PostPosted: Thu Jul 03, 2014 8:19 pm
by Steve Anderson
Softly, softly, catchee monkey...

Steve A.

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 2:14 pm
by Harry Dalek
Steve Anderson wrote:Softly, softly, catchee monkey...

Steve A.


Oh Yes its the only way :)

I have been thinking about the next Test ...but reviewing the last as to what i found out while doing it .

Something i noticed and i didn't take into account was that does seem critical the amount of amplification of the nbtv video to the video mixer for it to work out putting this to the laptop display Garys viewer and see an image ,its over loaded if to high but bugger all if volume was to low out of the phone .

My next test which i need to see if the samsung or iphone can light an led with the volume up and do a light video transmitter to the head amps light sensor ...this is of cause then connected to the video sync mixer circuit then the laptop display ...

I need to see if the head amp has enough amplification in a best case situation its a way of testing all the video part of the electronics with out having to deal with the rotating mirrors optics part for this test .

I will report back what happened .

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 5:14 pm
by Harry Dalek
Posting results of the Head amp test here .

I never even got to the the video mixer part trying the light transmitter to test the head amp.

There might be a problem with my test as i am using a red LED and i didn't try the video mixer between yet ,but any way i tested the head amp as the receiver and connected it right to the lap tops line input ,best result was the photo below but the led and light sensor were very close .

What i found was the resistor value that controls the gain connected to the light sensitive diode and one side of the power rail does control the gain but looks to me with out doing a frequency sweep test drops the bandwidth gain gos up i lost video.

You can get some distance hearing it detecting the video but so far at distance i didn't get any video images on the screen ,i know i have done this before with solar cell and had much better results ..perhaps room light and other factors may be why as well.

I will have a think about this if i got parts of the test wrong but looks to me like this part i am testing is a factor to be looked at and gotten right before moving on .

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 5:21 pm
by gary
Harry if I am following you correctly, wouldn't you be better off sending a frequency sweep through it rather than a video signal? Then do a spectral analysis on the sweep.

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 6:51 pm
by Harry Dalek
gary wrote:Harry if I am following you correctly, wouldn't you be better off sending a frequency sweep through it rather than a video signal? Then do a spectral analysis on the sweep.


Hi Gary
I will do the sweep test as i can see this stage is my Achilles heel .

Factors i think gave the poor results in that video transmitting test could be the
Leds colour frequency ......
What the band width frequency of the photo diode is,
and amplification which might of helped via the video mixer op amp's if i had used it ,i must give weak sync without using it .

I will take your advice and do a sweep test, I can understand it will show for sure bandwidth problems .

i think i have an app on my one of the 2 phones that will do a frequency sweep .

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 10:18 pm
by gary
Harry, if you need a sweep wave file and a frequency analysis just let me know - for me it is trivial, and is small repayment for your great images and videos.

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 10:53 pm
by Harry Dalek
gary wrote:Harry, if you need a sweep wave file and a frequency analysis just let me know - for me it is trivial, and is small repayment for your great images and videos.


Hi Gary

Thats ok i do have those here ,i forgot you had sent me a sweep test wav around the flying spot one we worked on that reminds me i would have that in my camera folder on this computer i will look.

But i did have an app using the samsung to try the test ...it was pretty bad viewing the sweep live it even dropped off before 10khz i am sure the solar cell test a while back was better than that ,i should look for that post .

To make sure i haven't done any thing wrong i will have a think about it and i will redo the test it tomorrow .

Thanks again Gary your good advice keeps me on the right path . :wink:

Re: Mirror Camera project

PostPosted: Fri Jul 04, 2014 10:59 pm
by gary
>To make sure i haven't done any thing wrong i will have a think about it and i will redo the test it tomorrow .

Harry that approach is the basis of every single tiny little bit of progress mankind has ever made..

Re: Mirror Camera project

PostPosted: Sat Jul 05, 2014 6:21 pm
by Harry Dalek
gary wrote:>To make sure i haven't done any thing wrong i will have a think about it and i will redo the test it tomorrow .

Harry that approach is the basis of every single tiny little bit of progress mankind has ever made..



Yes i hope so :) i hadn't redone the test yet as i got stuck into making a neater light transmitter for the test ,i had a large laser and led PWM version but just knocked this simple version up and its nice and small....and less messy than what i was doing yesterday with that red led in that same circuit .
I had a tiny reading light that no one was ever going to use again with a white light led so i added the circuit below.
So i can redo the frequency sweep test little easier this time .

A little off track but one of my sons Charlie age 6 was rather inventive today he came in with hes invention ,i can not tell you how happy i was ,now thats daddy's boy . :D
He put hes i pod in this box hes cut a hole for the screen looks rather effective ...just had to share this one .

Re: Mirror Camera project

PostPosted: Sat Jul 05, 2014 6:41 pm
by gary
Harry are you sure his name isn't Dilbert?

https://www.youtube.com/watch?v=g8vHhgh6oM0

Re: Mirror Camera project

PostPosted: Sat Jul 05, 2014 9:32 pm
by Harry Dalek
gary wrote:Harry are you sure his name isn't Dilbert?

https://www.youtube.com/watch?v=g8vHhgh6oM0


Thats a new one on me have not heard of this one ,Dibert must be like all of us as we were kids pulling things to bits to see how it works .

I have my fingers crossed for Charlie ,i am sure if he can play minecraft on NBTV monitor we will have another convert :D .

Well tonight i did the frequency sweep test on the photo diode ,i have lost the photo trany version once i find it i will test it .

It when much better tonight seemed to give better results than the red LED test yesterday ,the white led book light worked much better .

The tests to night are a frequency sweep for the photo diode head amp ....next i tried the large solar cell not pictured ,then the tiny solar cell...