Haven't found any no-load current vs voltage data for the CIM (AKA Chiaphua AKA Atwood AKA Chalupa) after a bit of searching. However, slide 5 of
this 2006 presentation from a DEKA guy gives some measured data for the 2005 KOP Fisher-Price motor. The relationship appears to be a linear one.
This is reasonable, since:
Code:
EDIT: Shamefully bad math deleted! See Eric's post below...
(Some
related threads)