DC 24V Power Supply - Please Help

[dimcha]

Dear all,

I need to supply power to string boxes. The requirements are 12 or 24V DC Power Supply. The boxes are far away from any power source. The string boxes are connected to the inverter through RS485 cable. Do you have any idea how I could supply power to that boxes? Actually, it's the control board which needs power in the string box.

Maybe it's a silly question. The RS485 cable, does it transfer both data and power or just only data?

Thank you in advance.

 

[BruceB]

Cables that take RS485 signalling often can carry enough to power what is at the end of them. RS485 goes on one pair, power on another. From memory my burglar alarm can do that to about 100m. But you really need to know what the power demands are and then size the cable to suit.

 

[dimcha]

Actually, it's a controller board inside the string box with power requirements: up to 24V and 300mA. You are saying that the RS485 calbe can carry power to the boxes: data on one pair and power on another pair?

 

[BruceB]

Yes. You will just need to check what the distance limits are from both the RS485 perspecive and power perspective.
Regards
Bruce