Professor Motor Controller

[Hotrodbob]

I have a Professor Motor controller, but it only works at full throttle. Can anyone guide me to what it needs to be fixed?

[waaytoomuchintothis]

I know how awful this sounds, but are you sure you didn't cross connect the leads? I did that once and everybody got a big laugh out of me. I still remember how red my face was.

[Hotrodbob]

[RichD]

There are two types of PM controllers, there is the older type based on the Slotworks diode controller and the newer trasistorized type. Niether type will work properly if it is not made to match your track polarity. Polarity refers to the direction that electricity goes through the controller, not to the track and cars. Most electronic controllers are made to work with what is referred to as positive polarity, Slot.it calls this common ground. 1/32nd set types are all wired for negative polarity, which Slot.it calls common positive. There are a few dual polarity controllers available. Electronic controllers usually bypass the diodes or transistor at full trigger, so the cars will run at full speed even if you have the wrong controller. If you have a diode controller PM had a dual polarity kit for those. A diode controller will work with the wrong polarity if the brake wire is left disconnected and the white and black wires are switched. In that case the brakes would not work of course. PM has not offered a dual polarity transistorized model. Possibly the wires that connect to the transistor can be switched, you would have to contact Professor Motor and inquire about that. You may end up swapping you controller for one with the correct polarity. One last possibility exists if you have a transistorized controller, the transistor may have gotten cooked and needs to be replaced.

[Hotrodbob]

Thanks!!!

[waaytoomuchintothis]

You have plugged controllers on plastic track! That makes a lot of difference. Absolutely, go with what has been said above. If you need repairs, PM is very nice about doing cheap, excellent diagnosis and repairs at their tech desk. I have used them on several ocassions on my equipment and others. Just call them in Livonia, Michigan and ask for the address to use and the name of the tech to direct it to, as in "ATTN: Soandso".

[Hotrodbob]

Yes, on plastic track. wired in place of Carerra controllers.

[RichD]

I should have mentioned that all set type plastic tracks are wired for negative polarity.

[Fubar Motorsports]

[Hotrodbob]

2 out of the three work on my home set up. Based on what you guys have said, maybe I have two for Carrera and one for commercial track.. I'll take it up to the local track and try it out.. Thanks for all the input.. If it doesn't work, off to PM for sure.. Thanks