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Powering project question

Thu Jun 14, 2018 6:44 pm

I am building a project consisting of a pi zero w, camera and TB6612 motor driver and two DC motors with 200-400 mA run and 1.5A hard stall. I have everything working as intended while having my pi connected to the wall and motor driver powered by AA batteries. However, the goal is obviously to make this mobile so I have been stuck on the issue on how to power the whole thing for a while now. Ideally I would love to power the whole thing with one battery like the adafruit 3.7v 6600mah battery and a T3608 voltage step up booster to get the voltage to 5v. Through researching this online I have come to find out that powering the pi and the motors with the same power source can generally cause issues. However the motor driver I am using the adafruit TB6612 has kick back diodes to protect against the inductive kick. Since I also plan on using the DC boost along with it providing me with a steady 5v I was hoping that I would indeed be able to use one battery to power the project. My question is do I still run into the same issues regardless of all this? Is powering this type of project with one battery simply not a good idea and I should stick to two separate power sources?

Thank you in advance!

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Re: Powering project question

Thu Jun 14, 2018 9:26 pm

The supply variations caused by motors at the various conditions they can face are very difficult to accommodate when also trying to power sensitive (and power-hungry) electronics systems. Save yourself a lot of grief and use separate batteries.
Military and Automotive Electronics Design Engineer (retired)

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Joined: Thu Jun 14, 2018 6:30 pm

Re: Powering project question

Fri Jun 15, 2018 4:58 am

Thanks for a straight forward answer. I am going to keep it simple and do as you suggested.

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Re: Powering project question

Sat Jun 16, 2018 1:28 pm

Probably too big and heavy for your project but I tend to use 12V lead-acid batteries. Mainly 'cos I have some, but also 'cos they let me run 12V motors and it's dead easy to regulate down for the electronics.
Submarine communication systems engineer and amateur robot enthusiast.

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