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Biggest MTC-Display ... or MIDIBOXes the world don't need?


doc

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Hi folks,

I felt a bit bored this weekend while waiting on several parts for other boxes.

But I wanted to solder something.

In every control room of every studio you'll find nice clocks on the wall. I find them boring.

So, what about a big MTC-Display on the wall, telling everybody whats going on?

Thought .... done.

My MTC display now is 85cm x 12cm large. It will be a nicer "wall-clock" than the usual ones.

The Display is based on TKs Midimon Projekt. I only added transistor- and ULN Drivers for the digits.

The digits didn't light below 8,5 V. So I powered them with 12V. I had to change the firmware a little bit to invert all DOUT outputs.

The digits are 100mm hight each and very bright. I'm gonna put them behind a red acryl-front and I'm gonna  build a nice case (the next time, I feel boring ...)

The schematic and the changed firmware I'll post, after I've written it down.

Have a midiboxing good time!

Doc

Sorry for the bad pictures. With flash it was too light and without it was too dark ... *argh*

MTC_thumb.jpg

2448_MTC_jpg6a8233fc57b26c8c23585af0238c

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That is great. I love big displays! Are you sure they are big enough? ;D

I did similar thing for cue management system, except I didn`t used factory displays. It was made 100% from scratch. Numbers are 200mm high and each segment have 20 super bright 5mm LEDs, and not multiplexed.  ::) Separation is made using some kind of foam material. Of course, laser did precision work and I did boring part... wiring  :-\

196983835_19b2dfbe68.jpg

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I haven't got a picture, but in 1979 I build a time display for an athletics meeting for a local club. Each segment used 7 3 foot fluorescent tubes, giving 6 foot high letters, (it may have been 7x2 giving 4 foot - I can't remember). The tubes had transformer pre-heated end filaments, and triac control of the ballasts. To save money is was fed by a 20mA serial loop. opto isolated, and all the drive electronics were live. In those days an SSR (even a small one) was over £10, and we would have needed 28 of them. The drive was simply an SN7447 driving  triacs through  transistor buffers. To avoid mains clicks, the data was latched into 4x SN7475's on mains zero, to avoid the cost of zero volt switching of each triac. We had to  put a wirewound resistor in parallel with each tube to avoid low current drop out. The cases were scrap aluminium panels from a local company that refurbished trucks. An electrical wholesaler who sponsored the club donated the tubes, ballasts and transformers, in return for their name on the front. We couldn't afford opalescent perspex, so used a 'mask' made of alloy, and baking parchment over the tube holes, then clear plastic on top. I still occasionally worry that it is in storage somewhere, and that some idiot will try firing it up again.

That's a very cool display doc, though I think Sasha now has to make an MTC with a pair of his. It might motivate me to get my MTC and MIDImon done. Nice work!

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Sasha's display reads right either way up, and reminds me of an old English joke about a boating lake, (they had them in parks: you could hire a rowing boat).

Man with loudhailer shouts out  "Come in number 99 your time is up!"

An assistant says to the man with the loudhailer ' But we've only got 72 boats'

Man with the loudhailer shouts "Number 66 are you in trouble?"

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@sasha

As long as you only have 3 digits .... Yes, it's big enough!  ;D

@TheProf

I'm sure that there are much bigger digits possible, but it's almost hard to explain why I made it that huge.  ;)

@Screaming_Rabbit

The digits are from Kingbright (SA40-19SRWA). I've ordered them for about 10 EUR a piece.

I don't know, if thats a reasonable price...

If you like, I can order some for you or shall we do a bulk order?  ;D

greets

Doc

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If you like, I can order some for you or shall we do a bulk order?  Grin

Bulk order..? Great idea! I really don`t see a reason why don`t we all make ourself 100mm MTC displays for our walls. The only problem for me would be going out on the roof so I can see the whole display trough window, but it is not big deal. Or better... make it remote and mount it on the building across mine. That would be cool!  ;D

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Bulk order..? Great idea! I really don`t see a reason why don`t we all make ourself 100mm MTC displays for our walls. The only problem for me would be going out on the roof so I can see the whole display trough window, but it is not big deal. Or better... make it remote and mount it on the building across mine. That would be cool!  ;D

Perhaps not a good idea to use Red LED's if you are doing that - the neighbours might start getting the wrong kind of visitors!

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I hadn't realized yours was that big. I glanced at the dimensions you stated and saved the picture, but just realized the other night that one of the things laying beside it was a 2x40 LCD. :o

You should get it to print messages, like "-record-" or something, triggered from MIDI messages. :)

Good Job! 

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  • 4 months later...

Super cheap giant digits at pollin.de - €1.95!!!

I paid > €8/pce. for mine at reichelt. Only difference to those from Reichelt (as well as Doc's in his circuit design), they're common Kathode... so you have to change the transistors in Doc's design and program the software changes.

http://www.pollin.de/shop/detail.php?pg=OA==&a=MjY0OTc4OTk=&w=OTg4OTk4&ts=0

Greets, Roger

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