I am creating a Raspberry powered WiFi car, called the PiCar :P
In the current design the entire system is powered from a single 9V battery which was salvaged from the same RC car which provides the 'base' for my project. I am currently using a UBEC to regulate the output between the 9V battery and a 5V rail from which the raspberry pi and a servo draw power from. The UBEC spec states that from a range of voltage inputs it will supply a 5V (constant) and 3Amp (max) output however i believe that the battery pack isn't sufficient to allow the UBEC to provide the 3Amp output.
My reasoning behind this belief is that during light usage, wifi dongle not transmitting large amounts of data and the servo position not changing rapidly, the system runs fine, however during 'peak' loads i think the servo and dongle are drawing enough current to cause the raspberry pi to cutout.
Here is my circuit diagram.
My question is therefore how would i modify my circuit to include some form of protection against this? I have read about using capacitors to achieve this but I am unsure of how to implement them and would like to avoid damaging my pi by overloading it accidentally.
What i envisage is some form of capacitor, or two, on the 5V rail that the Pi and servo run off?