Hello, I currently want to use a 9v wall-wart plug capable of putting out 650mA to power a small project of mine through a 5v regulator. The regulator itself is the 7805 and is capable of putting out up to 1.5A when correctly heatsinked. If I know for sure that I am going to draw no more than 400mA for my circuit at any given time, can I go ahead and use this regulator or will I have to buy the 500mA version? I think I would able to since the current being pulled through the regulator and the current usage of the regulator itself shouldn't exceed the 650mA given out by the wall-wart. Thank you.
AFAIK it doesn't exista 500mA version.. only 100, 1500 and 2000... it's no problem to load the regulator BELOW the value it's specified for... The problems start if you go above...
Yes, you may use the 7805 or 78S05, but not the 78M05 or 78L05 since you may draw more current than these are designed for.
