Eight
Member level 2
Hello,
I'm working on a project (theoretical stage right now) and I need some suggestions. I plan to use 6 LED chains of different colors - that's multiple 5mm high brightness LED's wired serially in a single chain (all LED's in a given chain are the same color). Normally they draw about 20mA of current when fully lit, but the voltage needed to drive a chain is going to rise since multiple LED's are wired together. Anyway, I'd like to build a mechanism to digitally dim these chains independently of each other and I was wondering what's the recommended way to do so. I'll be using a 5VDC microcontroller to do the dimming logic.
One option I was thinking about is using a PWM driver, if I use a simple resistor (leds + resistors = bad idea???) on each chain to match the PSU voltage (24VDC). However I cannot find any 6-channel IC's that can supply a high enough voltage to drive the chains. I found this IC though: **broken link removed** In addition to this IC I'll probably have to use something like a MOSFET on each channel to drive the higher voltage chains. Thing is I have no experience with mosfets, and seeing that the PWM driver operates on 97KHz I'm not sure whether this is going to be a problem or not. I'll likely need a high frequency switching MOSFET so can anyone please recommend me which one to use?
The other idea is to use a constant-current driver that can digitally adjust the current flowing through the LED's. Again I'm clueless what to use here.
Thanks in advance for any suggestions.
I'm working on a project (theoretical stage right now) and I need some suggestions. I plan to use 6 LED chains of different colors - that's multiple 5mm high brightness LED's wired serially in a single chain (all LED's in a given chain are the same color). Normally they draw about 20mA of current when fully lit, but the voltage needed to drive a chain is going to rise since multiple LED's are wired together. Anyway, I'd like to build a mechanism to digitally dim these chains independently of each other and I was wondering what's the recommended way to do so. I'll be using a 5VDC microcontroller to do the dimming logic.
One option I was thinking about is using a PWM driver, if I use a simple resistor (leds + resistors = bad idea???) on each chain to match the PSU voltage (24VDC). However I cannot find any 6-channel IC's that can supply a high enough voltage to drive the chains. I found this IC though: **broken link removed** In addition to this IC I'll probably have to use something like a MOSFET on each channel to drive the higher voltage chains. Thing is I have no experience with mosfets, and seeing that the PWM driver operates on 97KHz I'm not sure whether this is going to be a problem or not. I'll likely need a high frequency switching MOSFET so can anyone please recommend me which one to use?
The other idea is to use a constant-current driver that can digitally adjust the current flowing through the LED's. Again I'm clueless what to use here.
Thanks in advance for any suggestions.