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L.E.D.`s - series or parallel?

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Hero
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Registered: ‎17-05-2013

Re: L.E.D.`s - series or parallel?

What about using whatever material of your choice for the 15" x 21" surface, with a cutout to drop in a tablet such that the surface levels are flush?

You could then have your black lines displayed on the white background image.

Edit:  If required to alleviate the pressure of the drawing instrument on the screen you could use an additional clear sheet of perspex, which could even cover the whole 15" x 21" area.

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Seasoned Pro
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Re: L.E.D.`s - series or parallel?

I has a similar need some time ago (which turns out to be 2016 according to my Amazon account) and I resolved it by buying one of these it's not lit but it does have line guides, well to a degree.

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Hero
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Re: L.E.D.`s - series or parallel?

@Mook 

You're forgetting one of the main requirements ...

 

 

 

It must cost very little, as @shutter  will probably confirm!

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Community Veteran
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Re: L.E.D.`s - series or parallel?

@Mook   As @RobPN  said.......

Needs to be very cheap ! ..

 

Your suggestion is not practical for me... as I want to practice my pen and ink writing style(s) italic, calligraphy, and "illumination" work... ( as the old monks used to do with bibles, etc! ).

also it could be used for pencil copying of pictures, which could then be "highlighted" with coloured ink pens.

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Hero
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Re: L.E.D.`s - series or parallel?

@shutter 

It might be too expensive due to minimum order quantities but i would get a piece of aluminium (for cooling) and stick several rows of LED tape to it. Put a piece of glass or perspex over the top and drive that from one of your power supplies.  I use it for pelmet lighting in my kitchen and it works extemely well. 

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Aspiring Hero
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Re: L.E.D.`s - series or parallel?

If you have a fully functional laptop, why not just display a white image and draw over the top of it?

Alternatively, get a proper desktop monitor and use that.

If you already have these things, the cost would be zero. 😀

"In The Beginning Was The Word, And The Word Was Aardvark."

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Community Veteran
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Re: L.E.D.`s - series or parallel?

@VileReynard  I do have a fully functional laptop... however your suggestion is stupid....

Why? because you cannot write calligraphy on a vertical screen using a "dip in" pen, or even a fountain pen.. due mainly to gravity dragging the ink away from the end of the knib .

And as for the suggestion of "get a proper desktop monitor"..... well, i am not sure how that would work in the horizontal position, with pen and ink writing and drawing on the screen...

Apart from the stupidity of the suggestions, both are not in the criteria... of "low cost/cheap"  ..  as specified for a yokshurman ! ... due to the fact that I have not got a "proper desktop monitor"  nor do I need one !.

I also have a fully functioning brain, and am using it,    to produce what I have in mind, for the projects that I intend to do.

 

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Re: L.E.D.`s - series or parallel?

@Baldrick1  Yeah.. I have seen that LED tape... but thinking they may be "too bright" ! ...bearing in mind the limited clearance below the writing surface, and may also throw a beam as with the ordinary leds.  I would have to see some in action somewhere before contemplating them for use

thanks for the input though...

 

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Aspiring Hero
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Re: L.E.D.`s - series or parallel?

@shutter - all displays work in the horizontal position!

I assumed your ingenuity would allow the purchase of a bit of glass.

"In The Beginning Was The Word, And The Word Was Aardvark."

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Community Veteran
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Re: L.E.D.`s - series or parallel?

@VileReynard  in that case,.... send me a 15 inch desktop monitor flat screen.... free of charge of course...

Roll_eyes

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Aspiring Hero
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Re: L.E.D.`s - series or parallel?

Sorry - I don't think you can get one that small.

Can't your laptop screen lie horizontally?

"In The Beginning Was The Word, And The Word Was Aardvark."

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Hero
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Re: L.E.D.`s - series or parallel?

@VileReynard 

Have you skipped a page?  

See post #29 and post #31 above.  Cheesy

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Aspiring Hero
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Re: L.E.D.`s - series or parallel?

Probably! 🤐

"In The Beginning Was The Word, And The Word Was Aardvark."

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Hero
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Re: L.E.D.`s - series or parallel?


@shutter wrote:

@Baldrick1  Yeah.. I have seen that LED tape... but thinking they may be "too bright" ! ...bearing in mind the limited clearance below the writing surface, and may also throw a beam as with the ordinary leds.  I would have to see some in action somewhere before contemplating them for use

thanks for the input though...


I have had a play with one of my lengths of tape. The LEDS are on a 33mm pitch. To see how good it would work I printed out a table with thickish lines on one piece of paper then placed a blank piece over the top to see how well it showed through. The paper is bog standard 80g/sq.m. copy paper.

I would have thought that if this was placed a couple of inches away from the front it would do the trick. If it's a bit bright you could always turn the volts down and/or place a few more pieces of thicker paper underneath your lines.

A few rows with the LEDs positioned in an interlaced fashion might do the trick for you.

 

LED Tape bare

SAM_0390_edited-1.jpg

 

Covered with grid plus blank sheet touching LED strip

SAM_0391_edited-1.jpg

 

With grid plus blank sheet a couple of inches approx in front of LED strip

LED3.jpg

 

 

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Community Veteran
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Re: L.E.D.`s - series or parallel?

@Baldrick1  Thank you for taking the time and trouble to do the experiment.. and the result on the last pic looks encouraging... I will have another look on ebay to see what kind of length i am going to need for possibly three or maybe 4 strips across ( or up and down ! ).

Thanks again.

Much appreciated.  ( winking smiley face )

( as the smiley icon does not work for some reason )