5A range Current Sensor Module ACS712 Module

I have one of the current monitors and have been running tests on it
as a possible input for an Arduino programable controller

My idea for its use is to add automatic stops for a #60 trolley line
with a bumper at each end of the line.

The current sensor would detect the increase in current when the
trolley hits a bumper and reverses the motor and then would cut
power for a programed length of time for a station stop at each
end of the line.

In addition the time could be measured from one end of the line to
the to the other end, and this time could be utilized to make a station
stop in the middle of the line also.

There would be no wiring connections to the line except for the
track power to monitor the current and to cut power for the stops.
There would also be no modifications to the trolley.

I haven't used it, but it looks like it's popular, there's tons of listings for the same module from different people!

David,  

Our you using any Relays to slow down the Trolley before it hit the bumper black ?

Thanks, John