Banebots RS-775 Case Short

[Al Skierkiewicz]

Joe,
The Crio chassis is tied to the negative lead of the battery. The power lead to the Crio is not sufficiently low impedance to prevent (nor is the boost regulator capable of overcoming) a disturbance in the power to the Crio. If anything on the Crio finds a frame fault including the Crio chassis, considerable current (not full motor current of course) will then flow on that negative wire. It appears that in the motors opened last year, the majority of shorts occurred between motor windings and the armature. How close to one end of the winding that fault occurred is anyone's guess. A few appeared to be stray solder that migrated between a brush assy and the case. Another reason for concern is the possibility of two robots with electrical faults becoming engaged with current flowing between frames.
While it appears that the Crio can operate at less than 19 volts, the spec is to operate above 19 volts input.