A power supply maintains a set voltage, upto the rated current. The device (the load) is what dictates how much current is needed.
If your PSP draws, say, 300ma, you can connect any power supply that is more than that with no problems... a load is a load, it cannot be forced to draw more than it needs.
current is kinda like horsepower, your car might be RATED at 300HP, but that doesn't mean when you're backing out of the driveway you're using all 300HP... you just need a car to be RATED at enough horsepower to get the job done....it's there when you need it. How much is being used depends on the LOAD (ie if grandma is driving or the 16yo)
Therefore, you simply build a device that provides the proper voltage, 5VDC, and make sure the whole project is rated UPTO 300ma or whatever your PSP needs... this all is so don't worry about it.
official datasheet for your ship: http://www.national.com/ds/LM/LM7512C.pdf
10V for instance would fry your PSP, so you have to regulate it down to 5V with the LM7805 chip.
Well, the more you regulate it down to, the more heat you will dissipate and that LM7805 will burn the **** outta your fingers, so attach it to some sort of heatsink, the tab on your chip happens to be ground so you can just screw it down to a metal project box and it will absord enough heat to operate fine.
If your PSP draws, say, 300ma, you can connect any power supply that is more than that with no problems... a load is a load, it cannot be forced to draw more than it needs.
current is kinda like horsepower, your car might be RATED at 300HP, but that doesn't mean when you're backing out of the driveway you're using all 300HP... you just need a car to be RATED at enough horsepower to get the job done....it's there when you need it. How much is being used depends on the LOAD (ie if grandma is driving or the 16yo)
Therefore, you simply build a device that provides the proper voltage, 5VDC, and make sure the whole project is rated UPTO 300ma or whatever your PSP needs... this all is so don't worry about it.
official datasheet for your ship: http://www.national.com/ds/LM/LM7512C.pdf
10V for instance would fry your PSP, so you have to regulate it down to 5V with the LM7805 chip.
Well, the more you regulate it down to, the more heat you will dissipate and that LM7805 will burn the **** outta your fingers, so attach it to some sort of heatsink, the tab on your chip happens to be ground so you can just screw it down to a metal project box and it will absord enough heat to operate fine.
