Convert PM controller to negative help

[prem1032]

Hi, I would like some assistance to convert a positive controller to negative. One of our members has a controller wired for a positive track but our new slot car club is negative. We are located in Barbados and there is only one track in the island. I have volunteered to look into this and am willing to alter this controller. Correct me if I am wrong but it would entail flipping the 4 diodes in picture one and what about the transistor in picture 2. Do I move it to the “N” pins or do I replace it with a different one on the same “N” pins. The professor motor website shows a different transistors for positive and negative. As this is a great controller and there being limited scope for resale we would prefer to modify versus replace.
Thanks
prem

[RichD]

Your best bet would be to contact Professor Motor about this issue. Difalco Neo controllers are dual polarity, two wires need to be switched to make the change. I believe that all that does is to switch two of the connections to the transistor. Both the PM and Difalco controllers have diodes to protect against an improper hookup. In the case of the Neo controller the diodes do not have to be changed when the polarity is changed. If you are lucky with the PM controller you would only have to switch the two outside connections to the transistor, but I am not positive about that.