Controlling common negative LED string

Nuzzy

Apprentice elf
Joined
Aug 6, 2017
Messages
71
Location
Denmark
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

Bite my shiny metal ass!
Community project designer
Generous elf
Joined
Jun 12, 2010
Messages
4,157
Location
Victoria Point (Brisbane)
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:

 
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