Bringing this one back...
Now that we've got an operational layout, I'm taking another look at this issue.
Although the engine runs OK, I'm still bothered by the excessive current.
I had the engine apart yesterday, and I measured about 1 ohm resistance through the field and 2 ohms through the armature. Since I am regulating the field voltage through the PS1 board, is there any current limiting that would keep the field current from going haywire? Then I could just put a 1 ohm 5 watt resistor after the bridge that powers the armature from the track voltage is and cut my current that way?
I ordered some 5Watt 1 ohm resistors with the aluminum heat sink housings that I could attach to the frame. Should I put one in line with the field (in one of the yellow or white leads from the PS1 board as well?)
I figure if I'm pulling 6 amps at 18V, then my resistance is around 3 ohms, right? So by increasing the net resistance by 1 ohm, I could cut the current to 4.5 amps? If I put a resistor in line with the field as well, could drop it even more?