Specialty Driver Application -- Any Advice?

EthanOConnor

Newly Enlightened
Joined
Feb 8, 2010
Messages
3
Location
Seattle, WA
Hello All,

This is my first CPF post -- I've been a little obsessed with light sources ever since age 3 when my dad took me into the back yard at night, shined a flashlight at Proxima Centauri, and told me that in four years the light would reach it...
:candle:

Anyway, I have a lighting application in which I need to modulate 6 power LEDs independently from full off to full on at varying intervals aligned on a ~180hz clock. I have 8 channels of 5v / 40ma sources at my disposal, and I'm hoping there's a nearly-off-the-shelf solution that's essentially 5v/0v in on 6 pins to control 6 LED drivers.

This isn't a particularly challenging task, and I can rig something up from scratch if necessary, but it's not really my forté :)

I'm probably going to be using Rebel tri-stars wired in parallel @ 350ma.


Anyway, I'll post some pics and video of this application once it is up and running -- sorry to be vague for now.

Thanks to anyone with a suggestion!



Ethan O'Connor
 

EthanOConnor

Newly Enlightened
Joined
Feb 8, 2010
Messages
3
Location
Seattle, WA
For the initial prototypes I don't need the full brightness (thermal testing aside) so I'm trying the Maxim MAX16825, which is a three-channel, 150ma/channel current limiter with independent control of the channels at up to 1mhz, with easy daisy-chaining of chips for more channels running on the same control stream. External component count is two caps and three sense resistors...

Still looking around for a solution that'll provide similar ease of integration and control in the 350-700+ma/channel range. Package size isn't too important.

Thanks for any thoughts! I will post here with what I end up going with.
 

Magic Matt

Enlightened
Joined
Dec 22, 2009
Messages
444
Location
Near to Portsmouth, Hampshire in the UK
I'm pretty sure you wont get something off the shelf for this.

The only thing I could think of would be a PIC processor and manually generate the clock output duty cycles on the output pins - get one with it's own clock generator and you don't need any other components - you can literally run a PIC direct off a 3V cell (CMOS PICs are happy across 2V to 5.5V I believe). The sort of PIC chips I use only have one programmable PWM output - obviously you could use 6 small PIC chips and do it that way. Downside is unless you already use them you'll need to learn to programme them and get a programmer.

If you want the individual control to be automated in any way (fading from one setup to another for example) then I think PIC is the simplest way to go.
 
Top