LED-stripes for drum televisor

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LED-stripes for drum televisor

Postby DrZarkov » Thu Aug 11, 2016 4:34 am

Today I found at a discounter (Kodi) here in Germany these LED-stripes: 30 LEDs, length in total 1 meter. It runs on batteries, 4.5 V. Price: Only 3.95 Euro! Seems to be good for constructing a drum-monitor, the light should be bright enough to project the picture. I'm thinking about making a 30 line televisor for the German DRP-norm of it.

LED-strips.jpg
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Re: LED-stripes for drum televisor

Postby Harry Dalek » Thu Aug 11, 2016 10:26 am

DrZarkov wrote:Today I found at a discounter (Kodi) here in Germany these LED-stripes: 30 LEDs, length in total 1 meter. It runs on batteries, 4.5 V. Price: Only 3.95 Euro! Seems to be good for constructing a drum-monitor, the light should be bright enough to project the picture. I'm thinking about making a 30 line televisor for the German DRP-norm of it.

LED-strips.jpg


They look good are you thinking of a rotary transformer idea to transmit the signal voltage to the leds ?
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Re: LED-stripes for drum televisor

Postby Panrock » Thu Aug 11, 2016 6:17 pm

What is this "rotary transformer"? Please tell me more.

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Re: LED-stripes for drum televisor

Postby Harry Dalek » Thu Aug 11, 2016 9:59 pm

Panrock wrote:What is this "rotary transformer"? Please tell me more.

Steve O


Hi Steve

Well the idea is really Whats used for VCR heads ...or this idea
viewtopic.php?f=8&t=2075

as in the link in the first posting

Really just a transformer idea at high frequency but primary is stationary and secondary is rotating ...so thats useful keeping the electronics at the primary end and the modulating light on the secondary .

Wireless electricity - Inductive Power Transfer example

I was thinking each led in say Dr Z's mirror drum idea had its own coil but i suppose you could really hook all the leds up to one coil and just have a mask to view the leds perhaps as they sweep past the mask opening one at a time .
The frequency used for the transformers here is high enough bandwidth for NBTV .
I have tried it for just lighting an led ...about as far as i got with it ,also tried it on a vcr drum that worked as well as in powering up circuits on a rotary transformer ...no reason why you could not modulate that .
Last edited by Harry Dalek on Fri Aug 12, 2016 2:56 pm, edited 4 times in total.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: LED-stripes for drum televisor

Postby DrZarkov » Thu Aug 11, 2016 10:06 pm

That's an elegant idea! Indeed would one coil be enough, the LEDs are supposed to glow alltogether with only 4.5 V.
I would have done it in the more oldfashioned way, with an electric brush. But I like the idea to use induction.
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Re: LED-stripes for drum televisor

Postby Harry Dalek » Thu Aug 11, 2016 10:46 pm

DrZarkov wrote:That's an elegant idea! Indeed would one coil be enough, the LEDs are supposed to glow alltogether with only 4.5 V.
I would have done it in the more oldfashioned way, with an electric brush. But I like the idea to use induction.


Yes DR Z it would be a good idea for your drum ..may be simple idea would be say a 555 at say 40 khz feed that to a power trany or mosfet that feeding a primary coil of a few turns ...modulation to pin 5 of the 555 the pickup coil just experiment with caps across the coil i found best results you need to tune it in ,i suppose its really just like a radio receiver.you might have to experiment with the pulse width ....its all really the same sort of idea as in singing tesla coils such on the modulation side.
viewtopic.php?f=8&t=2001

some experiments here i stopped on this one as i was getting vibration at speed which you would not just with leds...might just need a vcr drum for your modulation transfer .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: LED-stripes for drum televisor

Postby McGee2021 » Wed Aug 17, 2016 9:00 am

I've tried these stripes before, and most of them that have flashing modes also have a little chip that seems to me to make it useless whenever I apply a signal to it. Most of them also have embedded capacitors that are invissible to the eye, because they are underneath the white protective coating. Only 2 of about 50 different types I tried were usable with television signals applied, so be warned.
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