I'm looking to purchase a power supply/wall-wart for a small pump. The pump is listed to operate at 12VDC input upto 3A. I'd like a 12VDC/4A power supply so that I may power a second low-current device (mA order) from the supply, but then I noticed the nominal voltage rating of the pump: 9-14VDC.
The nominal voltage rating is confusing me and I'm no longer certain if the 12VDC supply will be sufficient for the general operation of the pump. I think the nominal rating means that depending on the load, the voltage may fluctuate during operation. In this case, a higher voltage demand may draw more current, which the power supply should provide. Maybe -- I'm not sure anymore.
Is my concern warranted, or am I just thinking about this too hard?
Here is a picture of the "style" of the supply. I'm not sure if it is regulated, but it looks like a typical supply that powers household electronics such as printers, speakers, and small form-factor computers.