Deva_Rishi:
...the 7805's will tell you if it's okay, they have automatic shut down for over-current and over-heat.
i see, good to know !
Thanks, that puts my mind at ease 
PerryBebbington:
It doesn't work like that. The short answer is don't worry, it will do what you need.A DC DC converter swaps current for voltage.
i see - i kinda figured that the power (wattage) is the limiting factor.
conversely, with a boost converter, we can then expect a drop in the current ?
(eg. from a 5V@1A supply, we won't get 1A if we boost it to 9V)
PerryBebbington:
...
Just connect it up, it will be OK.
okay - i shall proceed with confidence !