I have a 5v 10A power supply that I am using to power my project. The project consists of a raspberry pi and 3 servos that are controlled by the pi through a PWM driver. The 3 servos and the Pi are powered from the same power supply.
The problem is that when I move all 3 servos I see the low voltage indicator pop up on the Pi. I don't have an oscilloscope to test how much current the servos are using but peak current is 600mA so the power supply should be sufficient to power everything.
Is there a way to split the incoming +5v into 2 isolated +5v rails that share a common ground?
That way I can use one rail to power the Pi and the other rail for the servos without the voltage drops triggered by the servos affecting the Pi.
I need to have a single power input that goes into the housing so I can't use two power supplies to power the Pi and servos separately.
Edit: Here is a an image of the circuit. I've marked out the important parts to make it clearer:
Best Answer
Isolated (galvanically) means "no direct conduction path between the two sides" and imply "floating", which is in direct contradiction with "share a common ground". However, isolated does not imply that if there is a high current load, the voltage does not drop, which is your problem here.
So "isolated" is not what you are after.
What you are after is a more stable supply. Even if your supply is correctly rated for the total current needed, it may not be able to cope with high current transients without the voltage dropping. The servos need higher current when they start moving.
You can add a capacitor close to the Pi to overcome this. A big electrolytic could be appropriate. Its minimum value depends on the layout, peak current value and duration, but something like 1000uF will most probably fix it.