Help required with switching problem

[eimaj12000]

Hi,

I'm currently working on a small project for my young nephew. This involves a section of track with rollers geared to work with a small DC motor. Now, here is the tricky part - I need a switching system which will detect a small toy car being placed at one end of the track and engage the motor to roll the car to the opposite end of the track. I want this to work the opposite way also i.e. so that the car placed on the far end of the track trips a switch which reverses the motor and rolls the car along to the other side.

I am not too good with electronics but eager to learn so any help would be much appreciated.

Thanks

[mvs sarma]

Hi
try IR LED and Photo tranasistor on either side to sense the car passing thro breaks the light path --use thr Transistor outputs to trigger set / reset flip flop

-the output could drive a relay with change over contacts to reverse the power to the motor