Mirror Camera project

[gary]

Ok can you run the 0v test again - but don't bother recording - but please check with the multimeter at "black level map", and also at "video out".

From the wave files it appears that you are either:

a) not getting a .8v clamp level, or
b) getting no sync

It's not possible to tell from the wave files which one it is because of the AC coupling.

BTW do you have any idea what the peak level of you monostable sync pulse is?

Edit: If it isn't too late you could also check the DC voltage (BTW all the voltages I have asked you to measure are DC voltages) at pin 3 of IC2.

[Harry Dalek]

The did the 12 volt and a 5volt Black zero video test so you could see it does not like 12 volts at the moment .

ermmm... not quite sure what you mean by that Harry but yes I want sync added in via the voltage divider r6/r7 by applying the monostable output in via top of R6

I will do but i did play a little with this today a direct connection from the monostable pin 7 to q1 base just stopped video out of ic2 ca3140...i will ad r6 and see.

BUT I also want you to turn RV1 completely to the left so the video input is pure black = 0v - then the cct should raise that to .8 V and the sync pulse will be added to that - i.e. it *should* go from +.8V to zero. All that means is we only have sync coming in - but it is ABSOLUTELY IMPERATIVE that RV1 be turned all the way down so we don't have any floating induced voltages floating about.

I will check and do that test tomorrow i will be interested to see , at 12 volts there is noise but as you can hear in the 12 volt test i just did .....this might be a problem for that test ...bit of a catch 22 problem

Please remember why I am asking this - I only want ONE thing coming in at a time otherwise there is just no way to sort out the mess.

[/quote][/quote]

I will cooperate but at 12 volts i hope its still ok.

[Harry Dalek]

Ok can you run the 0v test again - but don't bother recording - but please check with the multimeter at "black level map", and also at "video out".

I will give it another go in the morning....

From the wave files it appears that you are either:

a) not getting a .8v clamp level, or
b) getting no sync

Well best its been doing is .7 i might change power supplies just to see .
Running it at 5 volts i can view the video but record it does seem like that sync is missing .

It's not possible to tell from the wave files which one it is because of the AC coupling.

Ok it is hard when you don't have the thing in front of you .

BTW do you have any idea what the peak level of you monostable sync pulse is?

No not off hand Gary but needs to be dropped i could get the video to mix with the sync when i added a 680 meg resistor between mono output and Q1 ,i was just testing with my resistor wheel to see when it worked.

Edit: If it isn't too late you could also check the DC voltage (BTW all the voltages I have asked you to measure are DC voltages) at pin 3 of IC2.

Yes its .3 dc on a 5 volt supply and .7 on a 12 volt ....as i said i'll change power supplies tomorrow see if it makes a difference.

[Harry Dalek]

Just testing my voltages

The Power supply is 11.48 volts DC as is no circuit used with it .

When connected to circuits

With frame mirror relay disconnected and polygon motor.

power supply is 11.11 volts

With relay frame mirror on.... power supply is .....10.83 or 10.73 adjusting relays lm317 voltage adjustments one end or the other.

With just the polygon motor on power supply is 10.80 volts

With both polygon motor and frame mirror relay power supply is 10.80 no difference

I will move on to the circuit in the next post

[Harry Dalek]

Testing this circuit below.

Black level clamp PIN 3 CA3140 ic 1 is 0.94 DC....no video input at all and RV1 set to 0

Still with no video input adjusting RV1 its the same result set to full volume.

So thats a little high


Checking the 4528 monostable

The 4528 line pulse width is 10.55 volts pin 7 with a narrow pulse
and 5.9 on its wide setting which would be to wide to use.
These were DC measurements

[Harry Dalek]

Heres a little neater drawing of the motor control and sync circuits.

[gary]

That's good Harry - the voltages are close enough for normal operation.

I did ask you to measure at IC2 pin 3 - but I really should have asked for IC2 pin 6 anyway, could you DC measure that please?

(also what setting is your gamma switch in for interests sake? - for these tests please make sure it is in position 1 gamma = 1)

[Harry Dalek]

That's good Harry - the voltages are close enough for normal operation.

I wanted to make sure the motor side of it is not causing a problem.But thats good.

I did ask you to measure at IC2 pin 3 - but I really should have asked for IC2 pin 6 anyway, could you DC measure that please?

OK Its 0.96 pin 3 ic 2 CA3140
and its 1.24 volts pin 6

(also what setting is your gamma switch in for interests sake? - for these tests please make sure it is in position 1 gamma = 1)

its the same in the other gamma position for pin 3 and 1.66 on pin 6 on the other setting

[gary]

Ok good, Harry every thing seems fine except that you don't have any sync pulses (according to "v1 on 0.wav") - so it looks like either a sync connection error or a blown Q1.

You might want to get the DC voltage at pin of IC2.

Harry, I thought you had a CRO - is it out of action?

[Harry Dalek]

Ok good, Harry every thing seems fine except that you don't have any sync pulses (according to "v1 on 0.wav") - so it looks like either a sync connection error or a blown Q1.

Sorry Gary i didn't have the line pulse connected to Q1 ...
I wasn't going to change any thing but looks like i need it connected ...
I also have not got the 1meg resistor on the base of Q1 and to the positive rail connected yet .

Do you want me to do ad the resistor and sync to Q1 and do ic voltage test again ?

You might want to get the DC voltage at pin of IC2.
pin 7
10.8 volts

Harry, I thought you had a CRO - is it out of action?

Oh i have my little slab of a scope .

[Harry Dalek]

Ok good, Harry every thing seems fine except that you don't have any sync pulses (according to "v1 on 0.wav") - so it looks like either a sync connection error or a blown Q1.

Sorry Gary i didn't have the line pulse connected to Q1 ...
I wasn't going to change any thing but looks like i need it connected ...
I also have not got the 1meg resistor on the base of Q1 and to the positive rail connected yet .

Do you want me to do ad the resistor and sync to Q1 and do ic voltage test again ?

You might want to get the DC voltage at pin of IC2.

pin 7
10.8 volts

Harry, I thought you had a CRO - is it out of action?

Oh i have my little slab of a scope .[/quote][/quote]

[gary]

Sorry Gary i didn't have the line pulse connected to Q1 ...

Not saying a word...

Oh i have my little slab of a scope .

Great that will be a big help.

I also have not got the 1meg resistor on the base of Q1 and to the positive rail connected yet .

not positive rail see attached diagram - I think this should do it depending on the peak value of your generated sync pulses - if you had a 1m trim pot that might be better than 1m resistor - but by all means try 1m resistor - that way when you go to real sync it's all there.

BTW - once you have sync in the cct should be pretty much working - if the syncs are still too long we will have to try and find out why also we need to look into the 12v supply instability.

BTW2 - while I think of it might be a good idea now to ensure that pin 4 of ic2 is in fact connected to ground.

[Harry Dalek]

Not saying a word...

I didn't put it back on from the video tests as with it on theres no video out just sync..any case Whoops

Great that will be a big help.

I hadn't been using it much as i look at your big picture scope on any NBTV .

not positive rail see attached diagram - I think this should do it depending on the peak value of your generated sync pulses - if you had a 1m trim pot that might be better than 1m resistor - but by all means try 1m resistor - that way when you go to real sync it's all there.

Yes gald i waited ,i have a resistor wheel handy as i recall i tried a 1 meg but i think it was a 680 ohm that worked any case i will double check it was BTW same as how you are saying to ad the sync.

BTW2 - while I think of it might be a good idea now to ensure that pin 4 of ic2 is in fact connected to ground.

Yes i will double check and do the above .

[gary]

I didn't put it back on from the video tests as with it on theres no video out just sync..any case Whoops

Yes but what I was trying to do was get to the bottom of why the syncs are so long - pretty hard to do when they are not there! LOL

basically what I am trying to do is get to a stage where we have a black picture - i.e. no video signal - but even a black picture needs syncs.

The trick is we are trying to get the output of the mixer at 1vpp - with the sync portion being .3V - so a black picture will be .3vpp - once we have that we can add video - step by step, inch by inch.

I hadn't been using it much as i look at your big picture scope on any NBTV .

yes but it will be useful if we have to look at other parts of the cct besides the output.

Yes gald i waited ,i have a resistor wheel handy as i recall i tried a 1 meg but i think it was a 680 ohm that worked any case i will double check it was BTW same as how you are saying to ad the sync.

Anyway you can inject the sync pulses is fine for these tests Harry - no need to use my suggestion if you have an easier way.

BTW I just want you to realise that the height of the sync pulses from your monostable will have nothing to do with the height of the pulses coming out of the mixer - they need only be enough to saturate Q1 on and off (like a switch).

[Harry Dalek]

Ok gary i did the tests

i have a 1 meg resistor between pin 7 4528 monostable and Q1 of the sync mixer ...so i was wrong there 1 meg worked fine, but not sure about the the mixing side of the video with sync if this is the right value.

IC 2 pin 3 0.93 volts pin 6 0.30 volts with sync added.

Sync pictures below first is out of the 4528 pin 7....its a big pulse.

and the other is taken from R9 and R10 video out. theres a little wave to the pulses as you might of noticed in the pulse hight.

The ground was fine on ic 2