using TV to display audio signals

dnny · Last edited by dnny on Sun Apr 09, 2006 6:28 am; edited 7 times in total

Hi all this topic is all about

using TV to display audio signals.

you may have heard about Wobblevision , Wave Vessel , Analog Visualization Unit, AVU, Psychoscope, o-scope , b&w tv into a large screen oscilloscope kits - -
this is it all in one

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Before we begin, I have to give everyone a warning.
DO NOT ATTEMPT THIS PROJECT!
MODIFYING TV IS A DANGEROUS PROCESS. DO NOT ATTEMPT THIS UNLESS YOU KNOW THE DANGERS OF CAPACITORS AND
OTHER ELECTRONIC COMPONENTS. THERE IS A GREAT RISK OF POTENTIALLY DEADLY ELECTRIC SHOCK, AND THERE IS
THE POSSIBILITY OF FIRE OR EXPLOSION.
IF YOU TRY TO FOLLOW THESE INSTRUCTIONS, NO-ONE CANNOT BE HELD LIABLE FOR ANY DAMAGE OR DEATH CAUSED
WHILE BUILDING OR USING THE DEVICE

before you begin read these safety instructions:
Safe Discharging of Capacitors in TVs and Video Monitors
cathode-ray tube Safety Issues
Deflection System Safety

There are two areas which have particularly nasty electrical dangers: the non-isolated line power supply and the CRT high voltage.
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stay away from the red cable with the suction cup end.

after you have opened the TV unit wear rubber gloves! (longer sleaves better)

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the principal of this audio signal displaying is that
when TV is normally operated the Deflection Yoke generates a magnetic field and use it to direct the electron beam in the cathode-ray tube. Deflection Yoke gets signals from Deflection Circuit(Board) - Two of the wires control the horizontal motion, and the other two control the vertical motion. you just replace the Deflection Circuit Board signals whit audio signals and there you go.

i have made some schematics to clear how to route audio signals to Deflection Yoke- these schematics are based on information from Censtrons Wave Vessel page and my own experiments

first you need to find out the two horizontal and two vertical wires -
this will help

here you see the wires going to yoke
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H=horizontal
Hg =horizontal ground
V=vertical
Vg=vertical ground

here is the unmoded version
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whit this you can see normal TV programs

here is the Censtron version (a
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whit this setup you get a bar that differens in length (a bit like panel of Kit[car from Knight Rider] when it was speaking)
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here is the Censtron version (b
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whit this setup you get vertical line that vibrates
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here is the stereo version
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whit this setup you get pulsing circles
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the experimenting is still in progress so i will post more on this soon as i get more results

davep

mosc · Posted: Wed Jul 06, 2005 1:30 pm Post subject:

I appreciate Dave's warning, and the warnings that DNNY himself posted. As the admin here, I thought quite a bit about removing this post because of the dangers. I've decided to leave it here. There are many things in real life that are dangerous. Composing music can be dangerous too. Many years a ago a guy threatened to kill me because he didn't like my music, or maybe because his girlfriend did. Shocked

Well, working on TV sets is probably much more dangerous than composing music, but be very careful nonetheless. Also, be sure not to walk in front of a moving train and don't put your hand into a garbage disposal unit.

blue hell · Posted: Wed Jul 06, 2005 2:49 pm Post subject:

dnny · Last edited by dnny on Thu Jul 07, 2005 6:44 am; edited 1 time in total

mosc · Posted: Wed Jul 06, 2005 9:05 pm Post subject:

I am really sorry to hear you are not feeling well, Daniel. I certainly hope you weren't exposed to Xrays. Maybe you just happend to get some bug. I hope that's more like it. Be sure to rest up and get your strength back.

No no, I'm not going to delete the thread. I just said that I considered it. Maybe it is pointless to say I'm considering doing something and then not doing it.

You are right, it is good for people to learn from each other. That's what we are here for.

dnny · Posted: Thu Jul 07, 2005 6:41 am Post subject: X-ray radiation on TV

hi all im feeling lot better now

i called to The Radiation and Nuclear Safety Authority of Finland
and asked if i have been exposed to any radiation danger by moding my tv. and they sayid that there is very small possibility to get enough radiation from CRTs - in their test the maximum X-ray radiation from television has been 100mGy/h (hundred milliGrays per hour) and after that the tube has collapsed.

to get symptoms from X-rays you need to get at least 100Gy
the symptoms are then the same type of skin burns you get from sun.

the X-ray radiation on tv-set is stronger in the back of the tube than in the front. the X-ray borns when electrode hits the phosphor wall. X-ray bounces back to the inner walls of tube. it keeps bouncing and gets weaker and dies - the glass is thicker in the back so some x-rays get through but we are talking of really small amounts of radiation.

daniel

mosc · Posted: Thu Jul 07, 2005 7:35 am Post subject:

I'm glad to hear the chance of Xray radiation is small. Thanks for the update.

v-un-v · Posted: Mon Jul 11, 2005 6:00 am Post subject:

Hi all you twisted people! ;)

I found this little circuit link a while back looking for a TV oscilloscope- for all those who don't want to fry themselves!

http://www.intio.or.jp/jf10zl/tvosc.htm

It's on my 'to build' list but that could take a while to get round to. Please let me know if anyone has any joy with it.

Tom

dnny · Posted: Tue Jul 12, 2005 12:23 am Post subject:

v-un-v · Posted: Tue Jul 12, 2005 1:19 am Post subject:

Yeah the tele-scope looks great- but have you tried looking on the internet for a few of the chips inside? Secondhand oscilloscopes are really cheap these days (I bought mine for a tenner).

However, while we are on the subject of oscilloscopes, I found this one the other day;

http://www.elektor-electronics.co.uk/Default.aspx?tabid=30&ProductID=2418

dead cute eh?

dnny · Posted: Tue Jul 12, 2005 5:52 am Post subject:

Wild Zebra · Posted: Tue Jul 12, 2005 7:20 am Post subject:

Well I'll be darned. What will they think of next

Rob · Posted: Thu Jul 14, 2005 10:29 am Post subject:

Hihi, this is something I did when some 15 years of age. Connect the vertical connections of the deflection coils to the output of a small amp and turn the coils 90 degrees. Instant scope.

I was aware of the hazards and some experienced older fellow was looking over my shoulder when discharging the high anode voltage. Luckily I never got fried.

Around that time I did get quite a blow from a tube radio though. Luckily the radio fell from my hands as I was paralized by the high voltage. Have been very, very, very careful ever since.

As one can not depend on luck when messing around with high voltages.

mosc · Posted: Thu Jul 14, 2005 1:25 pm Post subject:

Experimenters who have been electrocuted while bending TV sets rarely post their stories on a forum... Crying or Very sad

All the rest of us have some shocking tales. Twisted Evil

dnny · Posted: Sun Apr 02, 2006 10:22 am Post subject:

update of my philips TX :

the thing that happened to my Philips TX is that i tried to get the most of it and i used a random coil i savaged from some "i don´t remember what".

so i connected the coil lets say it was 50mH to the points of horizontal and horizontal ground of the Deflection Circuit(Board) - and wow it was cosmic - the beam was so bright - it was just like looking to sun. well i realized that the unit heated a lot - so i attached two ventilators . . . and i took it to "koneisto" ( The Festival For Electronic Music in Helsinki) it was in stage whit Aavikko. it lasted one hour all most the whole gig and died of over heating Sad

but i have to say that no TV has ever be so bright! all the time it looked that it will explode any minute Smile

this is the setup what i did -
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so i have been looking for the next TV (victim) to my experiments -
and i got now a correct size coil from the broken Philips TX

and meanwhile Censtron has made their first color vessel:
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destroyifyer · Posted: Fri May 19, 2006 10:38 am Post subject:

oh, sweet, totally awesome. impressive stuff

yay

dnny · Posted: Thu Jul 20, 2006 12:53 am Post subject:

my Friend gave me a old soviet travel-TV that was not working but, it could display the usual noise. so i did the things described in this topic - but whit a 2mm pinjack -patch panel and speakon connector - so i can connect straight to my amp.
here are some pictures:

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not much space inside so i removed the speaker

the patch panel made of perspex:
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