Maker Pro
Maker Pro

ESD and Robotics

driesman

Jan 27, 2013
1
Joined
Jan 27, 2013
Messages
1
Hi (first time posting, so sorry if I missed any conventions):

I am mentoring my son's FIRST Tech Challenge Robotics team. We've been competing for three years and know our way around the hardware and software. This year we've suffered from random processor (Lego NXT) crashes and lockups. It also has been unusually cold and dry in maryland.

I suspect that we are having ESD problems. The kids are constantly getting shocked when touching the robot. They've also witnessed the NXT controller resetting when they've gotten shocked.

The motors, and motor controllers run off a 12V NiMH battery, the NXT controller and sensors run off a 6 AA batteries for 9V total. I suspect (don't have a schematic) that the two grounds are connected within the motor controller. The chassis is floating.

My thought is to take the battery ground from the 12 V and connect it to chassis in the hopes that this would keep the chassis from charging up. Thoughts? I can also connect the 9V batter to chassis ground (but it is harder to get to. Thoughts?
 

duke37

Jan 9, 2011
5,364
Joined
Jan 9, 2011
Messages
5,364
To stop getting a shock from the chassis, you need to earth it to ground so that it at the same potential as the operator.

12V or 9V will not give a shock. I expect that the voltage is derived from friction. This is quite common with plastic carpets in a dry atmosphere.

The spark which occurs will have a high current and very high frequency and could be picked up by any unshielded wire.

I believe that aircraft use conductive rubber tyres.
 
Top