Ok, as promised here are some pics showing the test. Paul - I would like to apologize in advance because these pics have nothing to do with AC motor controllers. I'm absolutely not trying to hijack this thread, just show some testing with a DI-145.
First, here is the test subject:
Second, here is the completely rebuilt drive system. Instead of a two cylinder pukey gas engine with a hydraulic drive system, there is the simple elegance of two electric motors.
Here is the ready to go test rig, wired as described in the previous post. Everything was logged on the laptop sitting on the right side. The grey electric box has all the "controls" - basically on/off switches to drive the contactors. The wooden board near the center has all the test and control stuff. On the left side are two Gigavac contactors. Near the center is the little DCtoDC converter, and on the right side is the DI-145. If you look close, you can see the LEM current sensor to the right of the right side battery.
Here is a close up of the "control" board. LOL!
Boy I never thought I'd post this....
The cable from the LEM is shielded, going to a plug that allows me to disconnect it from the test rig. From the Plug it's wired to the DI-145.
This is an example of the output. Top row is the current, as measured by the LEM, and the bottom two rows are the individual battery voltages. In this example, you can see the inrush current and how it pulls down the battery voltage. There are also two square peaks in the bottom voltage - this corresponds to a place where I turned off the right side motor to turn. The opposite motor actually has to pull harder to make up the difference - you can see that in the current trace and the opposite motor's voltage.
Anyway, as you can see it's possible to do much more sophisticated testing than this example.
But I was still able to get some important information about the performance of this system.
- E*clipse