I am using a linear regulator to step down the voltage for my microcontroller circuit, however, I noticed that when I power my microcontroller circuit from my laptop (at 5 volts) it pulls around 76 milliamps, but when I try to power the circuit with a 9v battery (or my 12v car battery) and the voltage regulator (L7805CV), then the current being drawn is only around 20 milliamps (instead of the 76mA that I get from my computer when powering without the regulator).
The voltage regulator output is 5volts as I would expect, but the current is being limited or something when the max should be 1.5Amps. I thought that maybe I burned out the regulator accidentally or something, so I swapped it for another one but am getting the same results.
(TOP VIEW) --------|====== Output (5v) | |====== Ground --------|====== Input (9v)
When I'm powering from the regulator I am getting 5 volts, but the circuit is only able to draw .20mA and the circuit is not working properly. When I am powering from the USB power supply, I am also getting 5volts but at 76mA, and the circuit works as designed.
EDIT I am not using the .33 uf or .1uf capacitors. When I get a min, I will try adding those, but I have a hard time figuring out how that would limit my current to .02amps when the max should be 1.5 amps.