Step by Step Thorana

Dear All. have a nice day

We are planing to make a thorana in our school using our school students

Please see the attach link for reference
https://www.youtube.com/watch?v=uRmyL1m3skM

1.We are planing to use Arduino for programming
2. We are using 12v 1.5w LED
3. We are planing to program like a matrix is working
4. Since Arduino can't drive 12v LED directly so we have issue with wiring method for multiplexing
5. We are planing to use step down regulator for power supply
6.We suppose to use 3000 LED's

Please see the attached for LED type

Advice is needed for wiring method and more


Thanks in advance

Hi,

Big project.
The most important is to know about the currents.
3000 x 1.5W = 4500W.
4500W from 12W = 375A.

I doubt you want to use (find) a single powersupply that delivers 375A.
Thus you need several power supplies.
I don't recommend to connect several switch mode power supplies to get one big supply.
If you follow this recommendation, then (now) you have several channels, each with one or multiple controllers.
--> decide which power supply you want to choose. Then go the next step.

*****
Multiplexing:
* if you want (almost) full 1.5W brightness: then the current needs to be multiplied (indeed mathematically divided) by the multiplexing rate (a bit lower not to overdive the LED. --> Read the LED datasheet about SOA when multiplexing).
DC current for a single LED is 1.5W/ 12V = 0.125A. With a multiplexing rate of 1/8 = 0.125 --> the "ON time LED current" should be close to: 0.125A / 0.1245 = 1A
I recommend no to drive them beyond 0.9A. --> read datasheet.

* if you don't need full brightness, then you may use lower power LEDs.

--> re calculate the overall power

****
You need careful wiring. Usual LEDs brightness is very critical with voltage. If you reduce voltage by 10% it's possible that the brightness goes down to zero.
--> read LED datasheet about V-brightness behaviour. Usually a LED brightness is very linear to LED (average) current.
Thus you may consider to use "current control" for the LEDs to get equal brightness, or you need to add series resistors (calculate power dissipation) to ensure almost equal brightness.
All the wiring creates voltage drop. This may harm (equal) brightness. Thus the decision above also influences wire gauge.
--> Calculate wire gauge not only about thermal considerations, but also on brightness (voltage drop) considerations.

****
As in the video there are several LED strings. Decide if you want to control each of your 3000 LEDs individually - or you are able to create groups of LEDs where only the "group" has to be controlled. (Makes LED control more simple)

****
Consider overall power dissipation of the controllers and the LED drivers. This may be a huge amount of heat. You may need a huge box, heatsinks, fans...)

Klaus

Take look at this video: https://www.youtube.com/watch?v=NLhFar_Q39Y

These "shows" are made with many controllers connected to a computer.
Your video shows a, relativelly speaking, simpler show. It might be doable with arduino, but not with LEDs that you gave us a photo.
First of all, make a design, figure out exactelly how you want the sequences to be, and then, somebody could help you with advices how to do it.

Dear Klaus

Great thanks for detailed information and advice

1.We are expecting to use China 350W 12v Power supply for every 200 LED's

2. In the multiplexing we do not have idea how we multiplex with LED driver and what you should recommend best LED driver that we can use in this project

3. In the wiring we are planing to make a PCB using CNC machine that we can directly sold the LED to PCB but we need to think about the cost

4. Since we are planing to wiring as a single color LED matrix so still we have a issue how we make a multiple using with LED driver

5. Should you think that we should use photocopier between Arduino and LED driver

I will update the few image of LED bulb arrangement and design of the Thorana

Please advice more thank in advance

Pasindu

Simply buy this strip and use SPI to control it
https://www.ebay.com/itm/50X-12mm-L...447882&hash=item41b78bf95f:g:1-MAAOSwKOJYJbIS

Hi,

Don't look for solutions before you defined your requirements.

We know:
* power supply: 12V 350W
* 200 LEDs per supply

We don't know
* if you want independent control
* do you want brightness control / or ON/OFF only
* what do you expect from the multiplexing / Why do you choose multiplexing
* what average current per LED?
* what multiplexing rate?
* ....your ideas

Klaus

As Klaus mentioned, you still have not defined your project, except no of LEDs and power supplies.
Why are you thinking that you will succeed with multiplexing?
First you have to define how many DIFFERENT elements you need (every element is one channel of your controller), not the total number of LEDs. Make a sketch/drawing of your Thorana with all elements on it.
Are your elements going to be dimable or not.