Paul Kimbrel's Musing

Before I popped open rotor controller, I decided to try it out. It certainly sent a signal to the rotor and got it moving, but the motor in the controller didn’t seem to be turning. After opening and poking at it a bit, it turned out to be a cracked gear. I guess I shouldn’t feel bad about opening it up. I traced the signals and figured out where everything goes.

Once I had that figured out, I started pulling the transformer out. The transformer had an awful lot of leads and from the traces, the best I was able to figure out was this: There are three terminals in the middle of the transformer and two leads (red and yellow) coming out of the bottom.

After consulting with Doug again, I learned that the (as pictured above) two right terminals are the primary winding. The terminal on the left is the common for the secondary windings. Yep, windings. Plural. Turns out there are two secondary windings in parallel with each other. Both put out roughly 20 volts in phase.

Here are Doug’s notes that he faxed me (which I subsequently re-drew in Visio - faxes aren’t kind to pictures):

The idea is that one secondary winding is used to drive the rotor and the other is used to drive the motor in the rotor controller. Well, I’m not using a motor-based controller in the end, so I just tied the two together since they’re in phase.

I hooked everything up and couldn’t get the motor to turn. Note that there’s a capacitor between the two output leads going to the rotor in the notes above. It seems that’s rather important. Doug informed me that the capacitor is there to shift the phase one of the wires relative to the other. This phase difference is what makes the motor turn one way or another. I have a bit of experimenting to do with this before I fully understand what’s going on there.

Up next… I hook it all up (correctly I hope) and get the motor to turn!