Running 12v props with everything else 5v

[scotthopkins234]

My current setup is a F16V3 running 5v for everything and pixels setup on ports on both sides of the board. I have a couple 12v floods I'd like to control from the same board. I think I can just run the data and v- from ports on the board to the lights and power the lights from a different 12v power supply combining the ground with the v-. I just want to make sure this is safe and not going to hurt anything?  

[tbone321]

Yes, you can do that as long as they have a common ground, IOW, the grounds from the two supplies are tied together.

[scotthopkins234]

Just to make sure I understand.. Is it enough to tie in the 12v power supply's v- with the v- of the light and the v- coming from the board, or is there something in addition to that? Thanks!

[algerdes]

Scott,
The reason for the tying of the v- to both power supplies and the control board is that v- does double duty in a 3 wire pixel setup. It is the return line for any v+ applications you may have and it is the return line for the data.  Every circuit, whether it is power or it is data, must be complete.

[Poporacer]

IOW, the grounds from the two supplies are tied together.

Tying the grounds together at the power supply might not work correctly, the data line needs the same reference so you should connect the ground from the controller to the floods at the point the 24V power is connected.

Like @algerdes stated, in our hobby we actually have 2 different DC circuits going on and they each have their own requirements.

[tbone321]

Tying the grounds together at the power supply might not work correctly, the data line needs the same reference so you should connect the ground from the controller to the floods at the point the 24V power is connected.

I agree that the data line needs to be at the same reference to ground and that is pretty much exactly what would happen if you tie the grounds of the two supplies together.  Unless you seeing a measurable resistance between the boards ground lug and the power supplies ground lug, the reference to ground for data will be the same at either point and it's usually easier to make that connection at the power supply lugs if they are close to each other.  Where exactly is 24V being connected?