hi,
my understanding was also the same as your answer:
whatever o/p rating for voltage was given, would appear at the adapter output - constant.
current rating gives you the max which can be drawn by a load- so if the current rating for the device was less than the current supplied by the adapter, it must be ok - only the required current will be drawn.
another piece of info got from a friend:
if a circuit draws more than the adapter's rated max current, then the adapter's voltage cannot be guaranteed to remain the same as its rated value. it would start decreasing.
my theory is:
the adapter would be destroyed if it draws more than its rated max current.
anyway, the reply and explanation given by the digikey tech, regarding pumping constant 500mA current, irrespective of the load, made me confused.
Thank you all for the explanations you gave.