Startup Power Sags Can Confuse Your ‘Bot

Here we are starting a new topics Designing robot power supplies, PCB Design Software, Robot Art, Practical Robot Design . You finally set your ‘bot on the floor for its first test run, hit the switch, and the computer starts acting all weird. A real bummer, especially since the robot works great propped up on struts on your workbench.

Chances are the problem lies with your power system. When motors start up, they require much more current than they use once they’re running. The battery will try its best to satisfy this bigger power requirement, but something has to give. In many cases, that “something” is the battery’s output voltage, which can sag so low that the robot’s MCU resets itself. Even worse, the MCU sometimes doesn’t reset cleanly, and “runs away,” executing garbage data from your EPROM. Continue reading