Help with electrical woes
 

I'm wanting to build a panel of LEDs (maybe 100+)
I've found this
http://led.linear1.org/led.wiz
Which tells me the wiring diagram. But...

What do I need other than the LEDs and the resistors? ie how to I source a power supply that is sufficient (and how to calculate it), what kind of board is best for sitting them in?

Basically... I'm an idiot who can solder ;)

Muchos gracias

Rob.

Re: Help with electrical woes
 

You need to make sure the resisitors are rated for wattage they will dissipate - and this depends on your choice and number of LED's. I tried a few random examples, and came up with recomendations of 1/4 watt (so I'd use 1 watt) and 1 watt (so I'd use 5 watts).
Supply needs to be smooth, most of the cheapy DC brick power supplies are far from it.
What are you doing?

Re: Help with electrical woes
 

Wanting to create a bright single wavelength light source (read: dicking around on my free Friday). Are there specific sources for LEDs?

Re: Help with electrical woes
 

wires. w.i.r.e.s.

no woes.

hth

Re: Help with electrical woes
 

But with multiple sources they wouln't be in phase - does that matter?
Would lasers be a better idea?
How about buying one of those cheap matrix signs, (i think about ?30 ish), and just programming the message as all big squares?

Re: Help with electrical woes
 

Why are LEDs a pound in the UK and 3p in China?!
Phase isn't an issue. I'd need AC rather than DC which looks a bit iffy

Re: Help with electrical woes
 

What LED's are you looking at for a pound?
They are about 10p normally.
take a look here http://www.ultraleds.co.uk/ they might have what you want already made up, they do strips of 48 leds etc

Why AC? they will still run off AC, but will flicker and have reduced light output according to the RMS of your supply - or you could just rectify your source?

Re: Help with electrical woes
 

The site tells you what current the array draws from the source. Multiply that figure by the voltage you intend to use (that you've also entered into the site) and that gives you the power rating required.
Power (in Watts) = V (in Volts) x I (in Amps)

eg. a 100 LED array (say 20mA current, 0.6V drop) powered on 12V gives 5 legs of 20 resistors, each with a 1ohm resistor, giving 100mA total current.
12V x 100mA = 1.2W (1.2VA)

For prototyping, why not use a spare bike battery? Should last 10-12hrs total loss from full charge.

"Breadboard" (often called stripboard or prototyping board) is good for cheaply building up this sort of thing. Don't blow your leds with too much heat though

Re: Help with electrical woes
 

Must........stay.........away.........from........ .Ultraleds...........website...........