What makes this LED display panel rather special is its age. It was commonly used in newsagents and tobacconists on their cigarette display shelves in the very early 80’s. That was when the very first home computers were first appearing. When LEDs were only really used as power indicators and in some very specialist scrolling message panels.
There were the first microcontrollers available back then (TMS 1000 and Intel 8048), but only aimed at hugely mass produced products with their development systems way out of reach of smaller manufacturers, so this controller is based on cheap and simple logic chips. Now it would be cheaper and simpler to do it with just a base PIC16 microcontroller and a ULN2803 driver.
The LED panel is a single sided board with a white side to reflect the light and the LEDs mounted sideways to bounce the light inside sections of a vacuum formed white plastic channel with each letter having its own light-box with a cut-out section on the front and an overlay with a block outline to translucent coloured letters.
Red and yellow LEDs were used because they were the only bright LED colours available at that time.
The controller has an unregulated 12V supply for the LEDs dropped to 5V via a 220 ohm resistor and zener. The chips are mainly a clock source, binary counter and shift register with some gating and buffering used to control the effects and drive the LEDs. The use of a bilateral switch for speed control is odd and the circuit also appears to be using the other switches as logic gates too.
It’s just a very odd and seemingly very reliable sign from an era where it was unusual enough to stick out as being “different”.
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And it still works.
Fuckin' love me some analog logic!
I remember seeing one in a Newsagent as a kid and thinking it was similar to the lighted logo to the kids BBC show Crackerjack (particularly the 1983 version seen at the end credits!) Way to get kids interested in smoking…
Does being born in '81 make you vintage?
Great video as always Clive
I really like that, I love how sharp and defined the lit letters are with no light bleeding. Very well made bit of kit, so glad that you saved it from the scrap yard, do you know where it was made?
Speaking of simple logic, I remember repairing squash court timers around 1980 that used a few 4000 series chips.
Simpler to do with a PIC? Maybe for those who can program them… I can't do it. I've tried. There are ZERO tutorials out there with the assumption that a person knows ZERO about programming. In my case, I would need to pay someone to program it, and then what? How can you sell it without putting them on some kind of royalties contract?
I love your videos, so thanks for all your hard work 🙂
I remember seeing these sign as a kid and always wanted one to put in my bedroom as it looked so cool.
I would've never thought that LED's had been used as most were quite dim back in the 80's when compared with modern ones.
Thanks for finally letting me see what made one of these signs tick :-)
off to buy some fags!. this advertising works
You need some FASHION probes to test this properly. Thought this would give you a chuckle http://www.ebay.com/itm/231804930834
Using a half a 4047 and a quarter of a 4016 to make what I assume is a simple two-speed clock? Any self-respecting designer would have built one with a couple of inverting gates and a transistor, and with a little bit of effort it could probably be done with just the 4016.
How the fuck do I find the size of PVC conduit appropriate for a certain amount of cables using the BS7671 IEE wiring regulations.
The "doing it with a microcontroller" equivalent of that time would have been doing it with an EPROM used as a pattern generator (sticking with relatively general purpose parts). A multivibrator, a counter and the EPROM – you're done. It would have been overkill for this specific application though and no doubt a lot more expensive… :)
Cannot be shown in public here as there is a ban on cigarette advertising, so this sign is no longer allowed to be displayed in a shop near the till or in the shelf.
What do horse's smoke…?
Fences & Hedges
Neat to see LEDs of that era being used for advertising! I think I was fiddling with old surplussed Monsanto and HP LEDs at the time
Cool effect when you turned the light off at 0:50. It looked like an overlay on the screen.
I had just left school back then and i got a job with a popular off licence chain – Arthur Coopers, i can remember a sales rep from that tobacco company coming in to the shop. He was trying to get us to put one of those up behind the counter. Unfortunately our company policy would not allow it because our entire cigarette display area was sponsored by a rival tobacco company. I was not overly happy because i had wanted to get my hands on it to see how it worked. 30+ years later i find out!
Another great video Clive. Loose the black paper though.
~stuffs burning tobacco into mouth~ argh the power of an old 80s advertising sign cannot be undone!
I think the bilateral switch is used to change the timing from fast to slow by shorting out one of the timing resistors instead of using gated logic on a constant high-speed pulse.
I think older stuff is more interesting than modern kit as the limited options require you to have a more thorough and concentrated knowledge in general. It's the same in computing.