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100 LED Display - Please help, my job depends on it!!

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I like the rotary switch idea

nice design but SMT LEDs would be easier to build IMO.
part #'s for the switches you have would maybe be helpful so he can get stuff ordered.
I started a design but got sidetracked to take grandson fishing.
 
another problem

when the rotary switch is rotated the privious LED will go off.
I think the op wanted the LEDs to remain lit??
dip switches may be only way to go??
 
But the most important thing is that the previous LED's remain illuminated, so if the count is '9' then 9 LED's are lit up and if the count is '76', 76 LEDs are lit etc.

Back to the DIP switches. IMO the OP doesn't have time to etch a PCB unless they have done so before and have all the necessary gear already. Point to point soldering would be pretty quick.
 
hi,
You did ask by PM for a S/R solution.????

This image shows the bare bones for the shift register.:)
 

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Thanks ericgibbs! I don't have access to any PCB manufacturing equipment and getting one made by a company is prohibitively expensive.

I have attached a file to show what the thing will look like, it will be made from 10mm perspex with adhesive vinyl cut out to the shape of the building overlaid on the front surface of the perspex. The circuitry will be mounted behind (somewhere near the bottom), each of the red holes is where the 100 LEDs will run up the centre. Does anyone have any suggestions on the neatest way to wire up 100 LEDs?? So far I am planning to use several pieces of stripboard as I cant find one piece big enough.

From top to bottom the perspex is 826mm...
 

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Wow, I thought it was Saturn 5B rocket!!!!:D

Dont forget, you need to mount the resistors for the 100Leds and require a suitable psu.

Give my regards to Castle Boulvard...:)
 
Just use veroboard to make 10 units with 10 LEDs, 10 resistors and one DIP switch. If you use 10mm (or even 5mm) LEDs then you will have lots of room to play with.

The nice thing is that this solution will keep count when you turn it off each night.

Mike.
 
Wire all the LEDs up in series, and use a simple flylead and small aligator clip on the back of the sign, to clip it on to the top led (highest lit LED). You can drive the LEDs with a constant current driver. Costs a couple transistors but saves 100 resistors.

At 100 leds it needs about 170v DC, which is a bit scary. So I would put them in 4 banks of 25 LEDs or something (now needs under 50v), and use 3 switches to light each of the 3 lower banks IF they are not the bank that is using the alligator clip.

Hope that makes sense.
 
I plan to use 5mm LEDs. I like the aligator clip idea but my boss isn't the kind of guy to be happy with that. He wants to be able to push a button or flick a switch, aynthing else and he'll panic!

@ericgibbs....if I use your solution, what power supply will I need for the circuit/LEDs?? Sorry for the probably very obvious questions...

Thanks for all your help so far guys, I'm trying to stay optimistic that I'll get it done, so far my boss hasn't picked up the smell of shear panic emanating from my desk...
 
I plan to use 5mm LEDs. I like the aligator clip idea but my boss isn't the kind of guy to be happy with that. He wants to be able to push a button or flick a switch, aynthing else and he'll panic!

@ericgibbs....if I use your solution, what power supply will I need for the circuit/LEDs?? Sorry for the probably very obvious questions...

So its 5mm dia LED's, please state colour, voltage and operating current.?
 
Too bad they don't make a 100 unit tall lite-brite. It's just black paper with a bulb behind it. Would have been bog easy to operate. Just add colored plastic pegs and they automatically light up.
**broken link removed**
 
How tall is that rocket??

An easy way to do the LEDs would be bar graph displays as I posted before.
neat, clean and not really expensive.
you could insert into dip sockets mounted on copper clad perboard.
you could light two at a time if the leds are too small.
thinking one 10 pos dip switch and a 10 pos rotary switch is all you need.
a power supply for each section of ten.
that picture of the building sure cries out bar graph displays
 
Hi,

just forget about my design. I didn't realize you want all LEDs on (bargraph).

Anyway, using 5mm LEDs you could try to get low current types of 2mA current.

In other words, any wall wart from 200mA output and up will suffice for the application. (Adjust LED current limiting resistors to the output voltage.)

Using the minimum of 200mA output you could probably use the power supply to perform fireworks when the one million is done. :)

Good luck with the project.

I can already imagine the diabolic grin in your bosses face switching from 10,000 to 1,000,000 with a single switch.

You can minimize this effect by connecting the switches as shown in the attachment.

Regards

Boncuk
 

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I like the Lite-Brite idea best - no LEDs, one AC bulb and 100 pegs. You could build an LED rainbow with that kit, as the scale progresses. Perhaps your job depends upon you working under pressure, not designing innovative electronic displays.
 
Actually in hindsight the lite-brite version would probably be the easiest. A florescent tube running the height, perhaps a diffuser to keep the light even, some black construction paper and a strip of wood or plastic with 100 holes drilled in it.

Can you still buy lite-bright to get the pegs?
 
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wonder how professional the lite bright idea??

nice idea but if you were a prospective client what would you think if you saw a light bright display in a bussiness enviroment?? just my opnion
I think I have a power supply solution on using LEDs
multiplexing using a 4017, 10 transistors, and a 555
using bussed resistor networks, dip sockets and project perf boards along with bar graph displays
look at mouser # 604 DC20/205RWA
has 20 ledsin a dip package measuring 50.7mm long 75mw 9000-31000mcd
ALL dip sockets for switches, ic's, leds. and resistors.
couldn't get any easier
 

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to save you time

ALL in dip packages except the 2n2222 transistors.
then itsall point to point wiring = simple, easy
here is a parts list if interested mouser.com
hope this helps as the clock is ticking


512-LM555CN .31 clock
595-CD4017BEE4 .43 multiplex ic
604-DC20/20SRWA $4.29 x 5 led display 9.85" tall
652-4114R-2LF-220 .58 x 10 14 dip resistor networks
653-A6T-0104 $1.60 x 10 dip switches
517-4808-3004-CP .16 8 pin socket
571-1-390261-4 .20 16 pin socket
517-4820-3000-CP .22 x 10 20 pin sockets
571-1-390262-5 .39 x 5 40 pin sockets
863-P2N2222AG .20 x 10 2n2222 transistors
 
Ok I have put together this circuit based on what ericgibbs has posted using a 74HTC164. It only includes the control circuit and the resistors for the LEDs. Each of the green pads will go to an LED. I have a couple of questions...

1) Have I done this right?!
2) What do I do with all the clock inputs?
3) Will this circuit definitely do what I need ie - count up by one everytime the button is pressed whilst keeping all the previous LEDs illuminated?
4) What power supply will I need if I am using 1.85V red LEDs with a 20mA operating current?

If I can't get this circuit sorted by the end of today I think I'm going to have to go down the dip switch route...

Thanks

Leo
 
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