Smallest CRT ?

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#2
I have a CRT thats Flat and is about 10mm diagonally. I dont know if its color or not, I got it from a camera viewfinder. I dont know how to connect it either...... lol. It has a 4 pin connection, my guess - 2 pins - power, 2 pins - signal.
 
#3
wow

Wow man 10mm is really amazing ! I will try to make some diy HMD ( don' t lol :- )) , and 2x 10 mm color crt's would be perfect for my project. 😱 However I' m not sure about its picture quality.. ( from very close 😕 )

BTW I seen some kind of security cam with 4" curved projection screen and I am impressed so much with it. It was using a monochrome crt, because it was from mid 20' s ........ 🙂 lol 70' s and it was probably using some 1" or less crt tube. I never seen like this before :bigeyes: that was very very weird device 😎
 
#4
#6
nice, what voltage was it running at?
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HIGH!!!

:att'n: SAFTEY WARNING !!!!!!! :att'n:

Due to the severe voltage dangers of CRT monitors, we dont not allow such discusions on DiyAudio of repairing or modifying CRT Monitors.

CRT monitors of all sizes carry voltages enough to kill a human very eficiently, and should not be modified/repaired unless you are a fully trained personel!!!. :att'n:

Trev:cop:
 
#7
focus

DigitalJunkie said:
My friend and I took apart an old camcorder one night,and found a tiny CRT in it's eyepiece.It's only black and white,but we found the power and composite video input.
Some pics of it at:
http://www.users.qwest.net/~ptaylor/Electronics/TinyCRT1.jpg
http://www.users.qwest.net/~ptaylor/Electronics/TinyCRT2.jpg
http://www.users.qwest.net/~ptaylor/Electronics/TinyCRT3.jpg

(You can kinda make out his PC's desktop.)
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thx man for the photos. btw desktop photo is very blurred, so is there any focus ( macro ) issue with the digital camera.. or crt is just displaying that blurred image ?
 
#8
Trev,

You are absolutely right about the high voltages in CRTs. I got shoked by one (about 20") and it aint pretty. But this crt is so tiny, it probably doesnt have more that 100-150volts, but hey, what do i know...

When I asked about the voltage, I meant what voltage was input, probably somewhere between 5-15 volts.

I too would like to know about the blurriness. I want to build a small projector using my 10mm crt, and a 15mm diameter projection triplet. Destination: 4 - 8 inch screen 😀
 
#9
But this crt is so tiny, it probably doesnt have more that 100-150volts, but hey, what do i know...
Click to expand...

Try 10000-12000v.:hot:

I too would like to know about the blurriness. I want to build a small projector using my 10mm crt, and a 15mm diameter projection triplet. Destination: 4 - 8 inch screen
Click to expand...

It wont work, they are simply not bright enough, a led is brighter then one of those things and leds cause eye damage when looked into. The manufactures arent silly enough to make a crt with a veiwfinder lens to go blinding people, the reso on those things are also lower then a tv, and no you cant make them brighter.

A 5inch crt will work but they still have a brightness issue, i tried out a 4inch crt on a BW travel set once and the image was that dull that i gave up on it. With an lcd projector, when u cant look at the lcd because its blinding bright, then u are on the right track. Thats somthing you will never get with a standard tv. CRT projectors use specially built tubes to yeald the extra light output and last only 8-12k hrs.

I know all of this because i too once hacked a cam apart with a crt veiwfinder, i changed the veiwfinder lens with a telescope veiwfinder lens which blew the image up, the reso was then very evidently crap. I also know all about CRT projectors and their dangers acociated.

Trev🙂
 
#10
wow! 10000-12000 volts on that little thing??? Damn.

I tried using a 5" blacknwhite tv, with a delta 4 lens, and got bright enough output to project 70 inches perfectly, 90" was pushing the limits.... But the edges were blurred because the tv was not flat. I need a 5 inch COLOR FLAT SCREEN TV. If anyone can get me one, plz email or post here.

"a crt with a veiwfinder lens to go blinding people"... that just made me laugh😀
 
#12
ace3000_1 said:


Try using a negative lens the same curvature as the tv screen, that should then fix the distortion problem, then you will have a flat tv screen😉 .
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Just what I was thinking... It would be very hard to find the right one, seeing how the tv is not round, lol. Since I have 3 more crt lenses, and all 3 have detachable negative lenses, I might give that a try right now.
 
#13
ace3000_1 said:


HIGH!!!

:att'n: SAFTEY WARNING !!!!!!! :att'n:

Due to the severe voltage dangers of CRT monitors, we dont not allow such discusions on DiyAudio of repairing or modifying CRT Monitors.

CRT monitors of all sizes carry voltages enough to kill a human very eficiently, and should not be modified/repaired unless you are a fully trained personel!!!. :att'n:

Trev:cop:
Click to expand...

Trev,

The actual stored energy in those HV powers supplies in eyepiece monitors would be hard pressed to kill much more than a fly even though the voltage is quite high. I'd be very surprised if it was over 4 or 5 kV BTW. The amount of current however in the average tube amplifier at a more leisurely 400 VDC is FAR more potentially lethal by many orders of magnitude. Some tube amps discussed on this exchange are very potentially lethal indeed at over 1000 volts and enough capacitor reserve to blow the end right off a screwdriver. Just to put this into perspective! I guess they don't teach this to Maytag repair personnel.

That hat is Maytag isn't it? 😉
 
#14
well that whole negative lens thing didnt work to my favor, it made things alot worse....

"Iraqnophobia...a fear of exploding automobiles" that made me laugh too....

Mr. S, you wouldnt happen to have a 5" flat screen Color TV would you? (4" or 3" is ok too)
 
#15
My 1st post, although I've read this entire board front to back 😉

I have a 3" color tv that I think I paid like $50(US) for a few years back. It has really nice picture quality for such a small screen. Wonder if I can use this...any suggestions. When I get home from work I will post the model of it to see if anyone can help me out.

I would also like to say GREAT site and THANKS to everyone who posts trying to help others out. I have in the past week got like 8 people wanting to build these things now just by telling them and showing them ya'lls results....

KEEP up the GREAT work...

Peace....RogueDogg



ancorp said:
well that whole negative lens thing didnt work to my favor, it made things alot worse....

"Iraqnophobia...a fear of exploding automobiles" that made me laugh too....

Mr. S, you wouldnt happen to have a 5" flat screen Color TV would you? (4" or 3" is ok too)
Click to expand...
 
#17
:att'n:

Rcavictim, without knowing what charge is stored in any given supply, any HV supply needs to be treated with the utmost caution. At multi-kilovolt levels, common-sense precautions are not sufficient. Please do not ignore or argue with moderator safety warnings.

:captain:
 
#18
SY said:
:att'n:

Rcavictim, without knowing what charge is stored in any given supply, any HV supply needs to be treated with the utmost caution. At multi-kilovolt levels, common-sense precautions are not sufficient. Please do not ignore or argue with moderator safety warnings.

:captain:
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Sy,

I operated a small commercial high voltage laboratory as one of my many hats and it was because of my knowledge I decided to point out, not argue with, that the concept being dictated by the other moderator that "discussion of ALL CRT based devices was verbotten discussion territory on these forums due to their danger to health" was disproportionate safety concern since tube amplifiers which are in fact much more potentially lethal for the reasons given can be freely discussed. These forums have both highly qualified persons in attendance as well as inexperienced amateurs. Handwaving gestures of generality without specific technical details are not sufficient in a technical forum.

I agree with your statement that "unknown charge" power supplies should always be treated with respect.
 
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