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Using TPS2113A power mux for robot power dock


#1

I have a Raspberry Pi B+ based robot built using Pololu parts and I want to add a power dock to charge the 5V battery pack (its a 5V USB battery pack) and also power the RPi.

Will the TPS2113A power mux switch power fast enough so as not to reset/brownout the RPi?
The datasheet does have a table for switching characteristics, but I am not sure if those are sufficient and what are the correct specs to be looking at.
https://www.pololu.com/file/download/tps2113a.pdf?file_id=0J771

I was also planning to use a separate mosfet switch to turn on battery charging for after the RPi has been switched to the power from the dock.

Thanks!


#2

Hello.

The TPS2113A power multiplexer seamlessly switches between power supplies and should be fast enough for the Raspberry Pi. However, I am not sure how you plan on adding your charging circuit to the system. If you post a diagram showing your plan for connecting your charging circuit, I might be able to give you additional feedback.

- Jeremy


#3

Thanks for that information! Sounds like the power mux should work great for my case.

I have attached a bad doodle of what I had in mind.

The battery pack I am using is similar to one of these, and has a micro usb charging port. When connected to a charger the 5V output gets automatically turned off.
amazon.com/gp/product/B00EF1OGOG

I am also worried about the mechanical design and electrical coupling for the dock since I will probably be drawing more than 1A at 5v while powering the raspberry Pi and charging the battery. Definitely don’t want to burn down the house :open_mouth: with my robot. Any pointers on robot charging dock design would also be appreciated.


#4

Your diagram and plan seem reasonable. For the charging station, you will probably want to mechanically/physically prevent the robot from connecting power backwards.

Good luck on your project. You might consider posting about it in the Share Your Projects section of our forum.

- Jeremy