Controlling common negative LED string

[Nuzzy]

Hi Guys,

I have one string of lights which has a common negative, how would I go about controlling these with Alan's DC30 board? All the other light strings are common positive so easy to control but how to reverse this one is stumping me at this time of night.

Thanks.

 

[David_AVD]

That's very unusual to have a set of lights with a common negative.

You could use some PNP transistors to do the "high side" switching like this: