Very Unusual Experience!
I just had this (for me) very unusual experience. Something that should have, in theory, worked, Actually seems to work! My treadmill DC motor controller arrived yesterday($29.00 from surplus center). I wired in the 5K pot., an AC plug and 2 jumpers from the output and went to bed hopeful.
Today I hooked everything up, and started the weichai. Then plugged in the controller. Then nothing, but 10 seconds later all the LEDs on the motor controller lit up and I was getting 260VAC output from the ST. A little adjusting down to 220VAC, Then dropped the engine speed a bit to 61HZ, and I went looking for some load.
I found 3 1750 watt space heaters, and plugged them in one at a time. Each time the engine loaded down a little, then the governor brought it right back. At just under 5KW the voltage dropped to around 215VAC and the freq. was 60.1. The DC output of the motor controller was around 65 VDC, and read no AC ripple. With things running under this light load the harmonic output was 101VAC.
I was thinking about how to unplug the motor controller to see if it would excite itself....when...it ran out of diesel and quit. Since it quit under load I probably didnt do hopes for residual magnetism any good.
The heat sink behind the output transisters on the motor board was just warm to touch. It's rated at 8A and I connected the two output jumpers thru 2 5A breakers. Dont have any way of measuring current draw thru the field, but doesnt seem too bad. Next time I'll use just one 5A breaker and that will tell me a little more.
After running 30 min under load, the radiator (original) on the weichai was hot, but could still hold your hand on it. So nowhere close to boiling.
Need to find some more load and see how it acts at 10 or 12 KW, which is my expected max need.
Again, thanks to Doug and all the rest of you fine folks. Never could have done alone.
Zeke