SparkFun Forums

[JudeWelsh]

I'm interested in the Picobuck LED Driver to drive several high brighness LEDs; the hookup guide mentions (and shows) four of the COM-13104 3watt LEDs in series - per channel.

The Picobuck spec mentions a max current delivery of 660 mA per channel with a jumper change. The hookup guide shows four 3w LEDs in series. Each draws 750mA, so that's (4x.75a) 3 amp current draw. This exceeds the stated 660 mA per channel.

I may only drive one 3w LED per channel, and that will still exceed the max current by 750-660= 90 mA (without changing the sense resistors)

Can a Sparkfun engineer or product specialist please clarify?
thanks
jude

[darrellg]

Connecting LEDs in series does not increase the current requirement. The current requirement for three LEDs in series is the same as one LED. It increases the voltage requirement, and 3 LEDs in series will drop 3 times the voltage as a single LED.

This is a user forum. If you want support from Sparkfun, you need to use https://www.sparkfun.com/technical_assistance.

[JudeWelsh]

My bad. Got it. thanks! Only caveat is that to use the 750mA LED I'll have to change the resistor as per instructions. cheers