Stepdown voltage

[jesse nobles]

I was able to get a bunch of free "broken" solar panels. They output 32vdc. I purchased a stepdown voltage device.


https://www.amazon.com/gp/aw/d/B01E...1497058121&sr=1&pi=AC_SX236_SY340_FMwebp_QL65

I want to run a bunch of 12volt fans in parallel. (I think).

So the question is. If I use this stepdown device. From 36vdc to 12vdc does my current increase 3x? Or stay the same?

 

[davenn]

So the question is. If I use this stepdown device. From 36vdc to 12vdc does my current increase 3x? Or stay the same?

the current is determined by the load ... in this case, what the 3 fans draw

 

[Irv]

I have one of those. If you draw much current, be sure one of those fans is cooling the step-down module

 

[BobK]

Theoretically you can get 3X the average current if you step down from 36V to 12V, but the devil is in the details. There is an efficiency issue, which will reduce it by 10 to 20%. And also, it is the average current that is reduced. In the typical buck converter topology, all of the current flowing to the load comes from the source during the on portion of the duty cycle. So, if the fans require 1A each you will be pulling 3A from the solar panels, but only 1/3 of the time, resulting in an average of 1A.

Bob