InGaN LED???

[ram]

Hi,

I recently purchased a Fridge Magnet in a local store. This has a button
cell at the back and when turned on has bright color led flashing. I however
could not see the LEDs, the magned had a transparent coating on top of a
plastic design I could see few wires on this plastic design.

I read somewhere that these are InGaN LEDs, but don't understand how these
are placed on the plastic. Can someone provide me with info. on how this is
done.

Also, I am looking for a circuit that I can use to randomly turn on/off
about 20-30 LEDs, can someone recommend a desing.


Thanks in advance,
Ram

 

[Fraser]

Is it like this:
http://www.siliconmachines.com/electronics/leds/cyberflower.htm

LEDs usually have a plastic domed package that totally encases the
small chip. In the case above the chips are mounted straight on the
circuit board and then the whole board is flooded with a clear resin
for protection.

 

[Watson A.Name - \"Watt Su]

ram" <rsunkara@sbcglobal.net> wrote in message
news:XVjVb.2077$PY.1145@newssvr26.news.prodigy.com...

Hi,
[snip]
Also, I am looking for a circuit that I can use to randomly turn
on/off
about 20-30 LEDs, can someone recommend a desing.

You don't randomly turn off 20 to 30 LEDs, unless you want them to all
turn off and on together, but at a random time. All you have to do is
connect each to a two transistor flasher circuit, and power it from a
common bus, along with the other 19 or so. They will then flash
randomly. Flasher schem at URL below.

http://ourworld.compuserve.com/homepages/bill_bowden/page5.htm#flash2.gi
f

Thanks in advance,
Ram

 

[ram]

Yeah, this is the one I am talking about. Thanks for the link.
Is it something that can be done by a hobbyist at home ??


"Fraser" <google@siliconmachines.com> wrote in message
news:f8f788e7.0402081221.56b6ef1e@posting.google.com...

Is it like this:
http://www.siliconmachines.com/electronics/leds/cyberflower.htm

LEDs usually have a plastic domed package that totally encases the
small chip. In the case above the chips are mounted straight on the
circuit board and then the whole board is flooded with a clear resin
for protection.

 

[ram]

Thanks for the link.



"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:102dotnl5u9qcd7@corp.supernews.com...

ram" <rsunkara@sbcglobal.net> wrote in message
news:XVjVb.2077$PY.1145@newssvr26.news.prodigy.com...
Hi,
[snip]
Also, I am looking for a circuit that I can use to randomly turn
on/off
about 20-30 LEDs, can someone recommend a desing.


You don't randomly turn off 20 to 30 LEDs, unless you want them to all
turn off and on together, but at a random time. All you have to do is
connect each to a two transistor flasher circuit, and power it from a
common bus, along with the other 19 or so. They will then flash
randomly. Flasher schem at URL below.

http://ourworld.compuserve.com/homepages/bill_bowden/page5.htm#flash2.gi
f


Thanks in advance,
Ram

 

[bj91504@binghamton.edu]

Also, I am looking for a circuit that I can use to randomly turn on/off
about 20-30 LEDs, can someone recommend a desing.


Thanks in advance,
Ram

How much money and time do you wish to spend. You could use a
microcontroller or a FPGA/CPLD Altera.

http://www.altera.com/products/devkits/altera/kit-max7k_quickstart.html

This is a nice kit and will allow you to build your circuit that is
almost random (no such thing as random with computers). But you will
also have to build driver circuit for each LED which is easy. If you
connect the output directly you will destroy your device. The altera
kit comes with a simulator so you can see if you program works before
programming.

Ok that 99 dollars and then you have to spend your time learning VHDL
buy a book. It really fun and you will feel great after learning this
programming language. But you can only program the max chip a couple
hundred times. So simulate then download to the board.