Author Topic: Prototyping an eggcrate control unit.  (Read 12660 times)

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Offline ComeOnDown98

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Re: Prototyping an eggcrate control unit.
« Reply #30 on: March 15, 2021, 10:51:12 PM »
Hmm... y'know what, as tomcat mentioned, eggcrates are pretty much entirely discreet.

That would mean they'd be easy to replicate, right down to the aluminum foam mask if you searched for a good material.

The diode card can be programmed in EasyEDA or some other CAD program, and you can use 1N5401 diodes as the bits. Cathodes hook to the "word" lines, and anodes to the "bit" lines.

Use BA9s sockets and 1820 lamps for the pixels. The diode card's outputs hook to the ground of the corresponding sockets, and the common (all the remaining socket pins) hook to +28V through a tan wire.


Then, the following colors hook to each word:


0 - black
1 - brown
2 - red
3 - orange
4 - yellow
5 - green
6 - blue
7 - violet
8 - gray
9 - white
Symbol - pink

And use a 0.093" (2mm) 12-pin Molex connector for hookup.
« Last Edit: March 15, 2021, 11:00:53 PM by ComeOnDown98 »

Offline ComeOnDown98

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Re: Prototyping an eggcrate control unit.
« Reply #31 on: March 15, 2021, 11:13:31 PM »
A follow-up: the diode placement on the board. A 1 indicates a diode present, and a 0 indicates otherwise.

Code: [Select]
0 - 0 1 1 1 0 0 1 1 1 1 0 0 0 1 1 0 1 1 0 1 0
1 - 0 0 1 0 1 1 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0
2 - 0 1 1 1 0 0 1 0 1 0 1 1 1 0 1 0 0 1 1 1 1
3 - 0 1 1 1 0 0 1 0 1 0 1 1 1 0 0 0 1 1 0 1 0
4 - 1 0 0 1 0 0 1 1 1 1 1 1 1 1 0 0 1 0 0 0 1
5 - 1 1 1 1 0 0 0 1 0 1 1 1 1 0 0 0 1 0 1 1 0
6 - 0 1 1 1 0 0 0 1 0 1 1 1 1 0 1 0 1 1 0 1 0
7 - 1 1 1 0 0 0 1 0 1 0 0 0 1 0 0 1 0 0 0 0 0
8 - 0 1 1 1 0 0 1 1 1 0 1 1 1 0 1 0 1 1 0 1 0
9 - 0 1 1 1 0 0 1 1 1 0 1 1 1 1 0 0 1 0 0 1 0
$ - 0 1 1 1 0 1 1 1 0 0 1 1 1 0 0 1 1 1 0 1 0

The result: (# indicates a bulb lit, _ indicates unlit or not present)
Code: [Select]
0
_ # # # _
# _ _ _ #
# _ _ _ #
# _ _ _ #
# _ _ _ #
# _ _ _ #
_ # # # _

1
_ _ # _ _
_ # # _ _
_ _ # _ _
_ _ # _ _
_ _ # _ _
_ _ # _ _
_ # # #_

2
_ # # # _
# _ _ _ #
_ _ _ _ #
_ # # # _
# _ _ _ _
# _ _ _ _
# # # # #

3
_ # # # _
# _ _ _ #
_ _ _ _ #
_ # # # _
_ _ _ _ #
# _ _ _ #
_ # # # _

4
# _ _ _ #
# _ _ _ #
# _ _ _ #
# # # # #
_ _ _ _ #
_ _ _ _ #
_ _ _ _ #

5
# # # # #
# _ _ _ _
# _ _ _ _
# # # # _
_ _ _ _ #
_ _ _ _ #
# # # # _

6
_ # # # _
# _ _ _ _
# _ _ _ _
# # # # _
# _ _ _ #
# _ _ _ #
_ # # # _

7
# # # # #
_ _ _ _ #
_ _ _ _ #
_ _ _ # _
_ _ # _ _
_ _ # _ _
_ _ # _ _

8
_ # # # _
# _ _ _ #
# _ _ _ #
_ # # # _
# _ _ _ #
# _ _ _ #
_ # # # _

9
_ # # # _
# _ _ _ #
# _ _ _ #
_ # # # #
_ _ _ _ #
_ _ _ _ #
_ # # # _

$
_ # # # _
# _ # _ #
# _ # _ _
_ # # # _
_ _ # _ #
# _ # _ #
_ # # # _

And the pinout, as viewed from the back:
Code: [Select]
Horizontal
1 4 7 0
2 5 7 +
3 6 9 $

Vertical
3 2 1
6 5 4
9 8 7
$ + 0
« Last Edit: March 15, 2021, 11:22:44 PM by ComeOnDown98 »

Offline tomcat

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Re: Prototyping an eggcrate control unit.
« Reply #32 on: March 16, 2021, 02:55:22 PM »
Hmm... y'know what, as tomcat mentioned, eggcrates are pretty much entirely discreet.

That would mean they'd be easy to replicate, right down to the aluminum foam mask if you searched for a good material.

The diode card can be programmed in EasyEDA or some other CAD program, and you can use 1N5401 diodes as the bits. Cathodes hook to the "word" lines, and anodes to the "bit" lines.

Use BA9s sockets and 1820 lamps for the pixels. The diode card's outputs hook to the ground of the corresponding sockets, and the common (all the remaining socket pins) hook to +28V through a tan wire.


Then, the following colors hook to each word:


0 - black
1 - brown
2 - red
3 - orange
4 - yellow
5 - green
6 - blue
7 - violet
8 - gray
9 - white
Symbol - pink

And use a 0.093" (2mm) 12-pin Molex connector for hookup.

That looks like an awesome plan for a project! I'm hoping more people take a look at designs for these and build them.

Brian

Offline ComeOnDown98

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Re: Prototyping an eggcrate control unit.
« Reply #33 on: March 16, 2021, 04:33:12 PM »
Yeah, Brian.

I even took the time to draw up a schematic for reference.

Wish I could share but I'm a bit of a n00b at sharing images from my hard drive...  :oldlol:

Offline ComeOnDown98

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Re: Prototyping an eggcrate control unit.
« Reply #34 on: March 23, 2021, 08:28:17 PM »
Okay, I got a Photobucket now. Here's the schematic:



Note how all the diodes are connected. Also note all the part numbers; the part numbers will be very important so as not to release any magic smoke!
« Last Edit: March 23, 2021, 08:30:41 PM by ComeOnDown98 »

Offline ComeOnDown98

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Re: Prototyping an eggcrate control unit.
« Reply #35 on: March 23, 2021, 10:38:51 PM »
Hmm... might start another thread since I have an idea and this one's dead anyway...

BRB...

Offline price_authority

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Re: Prototyping an eggcrate control unit.
« Reply #36 on: May 17, 2021, 03:09:56 AM »
The actual way eggcrate displays work is that they use diodes on an internal ROM card to map each pixel in the display.

When a signal pin is connected to ground with common referenced at +28V, the current is steered through the diodes and directed to the appropriate bulbs to be lit for the selected symbol associated with that pin.

That, @price_authority, is how these displays work.


There was no ROM in the original Display Systems readouts. ROM is read-only memory. That would require two separate power supplies: variable 0 - 28V for the lamps and 5V for the ROM chip. The lamps had to be dimmable. The ROM chip probably could not deal with a variable voltage. It would also require a way to program the characters into ROM. The old DS readouts were exclusively diodes — no ROM.

Lamp-matrix readouts were used in the '50's and '60's on Twenty One, Tic Tac Dough, The Price Is Right and Say When!! At the time I don't think solid-state diodes had been developed. I think they used a different technology, possibly involving relays. The readouts used on TPIR and Say When!! came from American Totalizator and were also used for race-track betting displays.

When TPIR first came to CBS in 1972 there was an asterisk as the first character in the readouts in contestants' row to indicate the winner. This took the place of the dollar-sign character in the readout. When they went to seven-segment readouts the asterisk was eliminated.

In the movie Quiz Show they did a remarkable job of re-creating the isolation booths on Twenty One. I have a pretty good eye for detail and the readouts and the mics were spot-on. I don't know if Ted Cooper was consulted for the movie, but he worked at NBC NY at the time so he may have been. I understand Ted worked on the "slips" for Concentration, the two boards that displayed the prizes each contestant had accumulated. I was once on the set when Classic Concentration was rehearsing. There was Steve Ryan supervising the slips. He had two stagehands operating the slips and it was WORK. They loaded a prize card every time a contestant called a number. If there was a match, they revealed the prize card; if not, they took down the prize card and awaited the next number to be called. Whew! It was WORK!
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Offline price_authority

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Re: Prototyping an eggcrate control unit.
« Reply #37 on: May 17, 2021, 03:30:52 AM »
If you were to replicate an egg-crate readout today you'd have to decide whether to make it alphanumeric or numeric-only. If numeric-only you can achieve some economy of design by connecting several of the dots together. With five PROM chips and corresponding ULN chips you could have a full alphanumeric character set.

You could then run a ribbon cable to drive the lamps individually. The driver could then be located remotely and be under the control of software. You could have  PC for loading the display, doing arithmetic, etc. and driving the LED lamps. For a five-digit display you would need to control 175 dots (5 x 35 dots per character). This would require 22 bytes of memory (22 x 8 = 176 dots).

I imagine what Wheel Of Fortune does is to have one PC for each contestant. They may have two graphics cards in each PC — one for on-set display and one for controlling it. I don't know how TPIR does bidders' row or the showcases now that they are under PC control. Does anyone know?
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Offline price_authority

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Re: Prototyping an eggcrate control unit.
« Reply #38 on: May 17, 2021, 04:08:57 AM »
Quote
Use BA9s sockets and 1820 lamps for the pixels.

You DON'T want to use 1820 lamps at 28V. They will be WAY TOO BRIGHT and will require an external dimmer. They will generate a lot of heat as well.

I proposed an alternative in an earlier post. I suggest you test a less bright lamp at 12V. It's probably plenty bright for a TV studio.

1892 — 14.4 volts -- .75 candlepower -- .12 amp -- 1.728 watts

For comparison:
1820 — 28 volts -- 1.6 candlepower -- .1 amp -- 2.8 watts (original)

So with 35 lamps you're looking at 60.48 watts with 1892 lamps vs 98 watts with 1820 lamps. That's almost 500 watts for a group of five characters. The studios use big honkin' rheostats to dim them.

I had a conversation with Ev Penn who was Display Systems, shortly before he died in 1981. He quoted me a price of $100 per character (comparable to a Ferranti Packard character).
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Offline price_authority

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Re: Prototyping an eggcrate control unit.
« Reply #39 on: May 17, 2021, 04:28:04 AM »
Here is a question for someone who owns a Display Systems readout:

What is the THICKNESS of the foam-rubber mask into which the holes are positioned? I have every dimension of the readouts except this.

Thank you.
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Offline price_authority

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Re: Prototyping an eggcrate control unit.
« Reply #40 on: May 17, 2021, 05:31:20 AM »
Quote
That would mean they'd be easy to replicate, right down to the aluminum foam mask if you searched for a good material.

The diode card can be programmed in EasyEDA or some other CAD program, and you can use 1N5401 diodes as the bits. Cathodes hook to the "word" lines, and anodes to the "bit" lines.

Use BA9s sockets and 1820 lamps for the pixels. The diode card's outputs hook to the ground of the corresponding sockets, and the common (all the remaining socket pins) hook to +28V through a tan wire.

Instead of being locked into Ev Penn's design, why not go with a 16-pin connector? Ev's design could be incrementally improved upon.

1 Common
10 Numerals
5 Additional characters: $  +  - * OVER BUST blank, etc.

I don't know much about 3D printing but I think you could make your mask as follows. Take a slab of white plastic cut to the proper dimensions and laminate it to an identically-sized sheet of VERY THIN matte black plastic, then cut the holes with a 3D printer. This would emulate Ev's original mask. Heat is still a concern which is why I suggested going with the 1892 lamps if you're not going to use expensive LED's.

What about a housing for your readouts? Are you going to drill holes in your PC board for the lamp sockets and diodes or go with pre-drilled boards? You will want your circuit board to be BLACK on the forward-facing side.
Before you call your lawyer to sue me, know that everything contained in this post and in all of my posts past, present and future is entirely MY PERSONAL OPINION.