So this is a somewhat general circuits question that has been bugging me for a while now!
I am trying to design a circuit that will power both a microcontroller and a dc motor which will be enabled/disabled via the microchip. I can use 5 volts for both the chip and the motor, but i am concerned about the current supply.

I obviously need a power supply that can source enough current for both the motor and the chip at the same time, but what happens when i am not using the motor (which is most of the time) wont the excess current fry the chip?

Thanks in advance!

 

As long as the right voltage is present at your microcontroller, it shouldn't get fried. It's only going to consume the amount of current it needs at 5V. If you apply, say, 24 volts to your microcontroller, then it'll get zapped.

If your supply is well-regulated and can supply enough current to power both the microcontroller and the motor, you should be OK.

 

Be sure to run separate power and ground traces to the uC and motor circuitry back to the source and decouple heavily there. Don't make the uC (or other sensitive stuff) share power with the motor. As jwilk13 said, your regulated power supply will handle the varying current loads.

 

This is why "Ohm's Law for noobies" was written. Top of the "Chat page. Read it.