dimmable LED control board

[Todamont]

Hi. I'm making a stained-glass peice for a friend and I'd like to have around 500 LED lights set behind it, controlled to light / dim / off in predefined sequences with a standalone PIC control board, powered by a 5V supply. I have a BS in computer engineering, but it's been a while since I did any hands-on electronics projects... Programming the PIC is not an issue, I know how to do that part.

I'm looking for a driver board (or just a component) with transistors that I could drive with the PIC to supply power to the lights. As I said, it needs to be standalone, so my buddy can just turn on the power and use a simple switch to choose between maybe 3 display patterns. I probably only really need 8 "channels", dimming would be a great feature. Is there an IC just filled with FETs that would handle powering say 80 LEDs on each pin? Could anyone recommend a schematic with minimal components? Suggestions would be greatly appreciated~

Ryan

 

[sahu]

Hi. I'm making a stained-glass peice for a friend and I'd like to have around 500 LED lights set behind it, controlled to light / dim / off in predefined sequences with a standalone PIC control board, powered by a 5V supply. I have a BS in computer engineering, but it's been a while since I did any hands-on electronics projects... Programming the PIC is not an issue, I know how to do that part.

I'm looking for a driver board (or just a component) with transistors that I could drive with the PIC to supply power to the lights. As I said, it needs to be standalone, so my buddy can just turn on the power and use a simple switch to choose between maybe 3 display patterns. I probably only really need 8 "channels", dimming would be a great feature. Is there an IC just filled with FETs that would handle powering say 80 LEDs on each pin? Could anyone recommend a schematic with minimal components? Suggestions would be greatly appreciated~

Ryan

i think it usefull for u ...https://hobby_elec.piclist.com/e_pic6_b.htm

engoy with it.........

 

[Todamont]

Thanks for the info! So if I want, say 20 lights to be controlled by each pin on the PIC, should I just string them up in parallel (replacing the single LED in the diagram with 20 LEDs in parallel)?

I'm figuring a max draw of 1A gives me about 50 LEDS on at a time (at 20mA per), or two strings on full, one dimmed. I suppose I should try to find a 3 terminal regulator that can source 1A at 5v (5 watts at a time)? Maybe I can find some LEDs that will be bright enough to illuminate the glass well at like 2 or 3 volts.

Again, I greatly appreciate the help of the forum members~

 

[geko]

Thanks for the info. So if I want, say 50 lights to be controlled by each pin on the PIC, should I just string them up in parallel (replacing the single LED in the diagram with 50 LEDs in parallel)?

Try this site for help in designing the LED array
**broken link removed**

All you then need is a MOSFET(s) to drive the array. Something like that used on this PWM driver Power MOSFET RGB LED PWM