Topo Map with flashing LED

Thread Starter

lednoob

Joined Jan 13, 2016
171
Hello, I am going to build a topo map that has LED lights that hopefully will fade in and out. Possibly 200 - 300 led's. I am looking for a circuit diagram. I would like for the led's to flash and maybe add a chase without programming. Not sure if I should use 555 timers and 4017. Can anyone help?

Thanks,
Steve
 

GopherT

Joined Nov 23, 2012
8,012
Hello, I am going to build a topo map that has LED lights that hopefully will fade in and out. Possibly 200 - 300 led's. I am looking for a circuit diagram. I would like for the led's to flash and maybe add a chase without programming. Not sure if I should use 555 timers and 4017. Can anyone help?

Thanks,
Steve
Lots of options. Lots and lots of options. What do you really want.

Note that 300 LEDs will result in a very large number of wires that must be cut, stripped and soldered. A large number of transistors and timer chips, a large number of holes to mount the
LEDs ... We are taking about thousands of connections with no chance of an error or it will not work. Not a beginner project. Maybe start with a 4x4 matrix to get it to work and decide if you want to invest in a project like that (dollars and time).

Here is how complicated a project like you describe can become...

 

Thread Starter

lednoob

Joined Jan 13, 2016
171
OMG dude that is crazy awesome!!! Much more advance then what i need but would love to do something like that in the future.

I would like to add LED's to a 67" x 48" TOPO map showing the rivers and terrain. There will be 3 buttons to activate each set (channels) of LED's First set is Red, second is green and third is blue. Each set is approximately 200 LED's except the red is about 300 depending on spacing. The map is mounted on a plastic foam material so I will drill each hole to hold a 3mm or 5mm LED.
When any of the buttons are pushed, all the LED's per that color would fade in and out continuously for 15 seconds then reset back to off.
I'm not sure how I would go about doing this. I will probably solder the current resistor directly to the LED's. I'm not sure how to do the fade in & out controlling and adding LED drivers for the long run. Sorry I am new to this but eager to learn.

Thanks again,
Steve

Oh and I love the coffee table!
 

Wendy

Joined Mar 24, 2008
22,146
Having said that, bed time for me. I have tagged this thread so I can follow it, so I'll be back my tomorrow.
 

Bernard

Joined Aug 7, 2008
5,561
Might consider a higher V than 12 V, say 36 or 48 for drivers & LED's, 12 V for circuits. At 36 V could have 9 LED's in series.
I would suggest measuring forward V of all or 20 to get an average V. It takes about 4 sec. to measure a LED. If LEDs are in piles of = V then strings can be assembled to have almost = V. Might be able to add another LED with with balanced strings.
Where it is not possible to directly wire LEDs together & if LEDs have square leads, then wire wrap works well without soldering. Works with resistors if soldered. spot of hot glue holds R in place..
Should consider pulse width modulation, PWM, for throbbing.
 

Bernard

Joined Aug 7, 2008
5,561
Working with unknown figures gives educated guesses using 48 V supply:
Green 16 LED's /string, 7 strings for 100 LED's @ .02 A = 124 mA
Red 18 LED's / string, 6 strings for 100 LED's@ .02 A= 120 mA
Blue 13 LED's / string, 8 strings for 100 LED's@ .02 A= 160 mA
Or 420 mA if all on at the same time. or @ .015 = 315 mA.
For comparison, 48V PS @ 380 mA, $ 5.5, All Electronics.
 

Wendy

Joined Mar 24, 2008
22,146
There are disadvantages with that scheme.

1. One diode goes out, the other 20 or so diodes go dark.

2. While the current requirements are reduced, 48V is not completely safe. It can knock you on your butt. Wire is pretty cheap too, especially 28 gauge. The advantage to a higher voltage is to use less wires.

3. You will need a separate voltage generated by a regulator from the 48V. Most IC regulators stop at 40V. You can use a zener of course, but resistors are cheap. My cost is less than 4¢ each. Quantity is 2¢ each.
 

Bernard

Joined Aug 7, 2008
5,561
True, but what is the MTBF of a LED? If I were doing it, would be a 24 V supply.
And note that LED figure is 700 rather then earlier figure of 300.
Think a punch might be better than a drill ?? From poor memory think I punched some 260 holes in compressed corrugated cardboard with 3/16 punch that had a spring loaded centering pin. Tolerance was 1 mm.
 
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