I want to power some hobby servos from a USB 5V supply. I am daisy chaining 2 ports together from a powered hub so that I can draw up to 1A. Should I power the servos directly from this supply, or is there some kind of simple protection circuit that I should add between servos and USB supply to prevent accidental damage to the hub?
USB 2.0 and 3.0 standards have battery charging profile and configurations to support drawing more current than that.
But if USB 1.0 the maximum current you could draw is 500mA.
Either way you need to communicate with the host, so specific chip is required.
-- please note that I'm not working for maxim. :P
The best way to drive your servo is by using a servo driver/motor driver (circuit), it amplifies the electric signal and transfers required current to drive your servos. You just have to give input from your USB to servo driver and output from driver will provide sufficient current. I did a project and it worked for me.
By using motor driver:
1) You can avoid any accidental damage as you mentioned above.
2) 1 port USB supply would be enough as well (not sure).