Reactive power - Reactive Generator research from GotoLuc - discussion thread

[poynt99]

Okay, I'll look into it. What if I connect it directly to my computer through USB is there an application for it?

The Scope is a loaner from Thane Heins

Luc

Yes, you can connect the scope directly to your PC through the rear USB port, but you will need to install the software in order for the scope to be recognized (drivers) and to port over the images. I'm not sure if Tektronix has the software freely downloadable from their website, but I will check.

That was nice of Thane to do that. You must be one of only a few people that are in his good books.

ETA:

OK, I found the free software. It is called "Openchoice Desktop Application"
http://www.tek.com/oscilloscope/tds210-software/openchoice-desktop-application-tdspcs1-v23-0
You need to log in to download it. I am downloading now. It is 414MB. How may I get this to you?

[poynt99]

No!... it's connected across the gen exciter coil and cap.

Luc

I meant the Watt meter that is plugged in to your generator, not your DMM meters.

[poynt99]

Okay, here is a video demo of the circuit I was getting 90 watts out for an apparently smaller amount in.

Link to video: http://www.youtube.com/watch?v=nr2-qIX9G3U&feature=youtu.be

Thank you Luc. You answered my question. For your other tests where you had a negative MEAN and CH2 was inverted, did the MEAN value also change when you went to non-inverted? By change, I don't just mean from negative to positive, but did the actual value change too like it did in this video?

This gives me something now I can investigate.

btw, the MEAN value amplitude should be the same (to the best of my knowledge) when changing from inverted to non-inverted, so something strange may be happening there. 

[poynt99]

OK Luc,

I've figured out a big part of the puzzle.

Thank you for showing the channel settings on your scope. When I changed the coupling on both channels to "AC" on my scope, I got the negative MEAN value. I of course have been using "DC" coupling, and you need to also.

The reason that we can't use AC coupling is because doing so inserts a capacitor in series with the probe input. The capacitor is not large enough in value to pass 60Hz without altering it, and it is this alteration (change in wave shape) that is causing your negative MEAN value.

Even if I only change the CH2 probe back and forth from AC to DC coupling, the MEAN value will change from +2.5W to -2.5W. You can see a slight change in the CH2 wave form shape when changing back and forth.

See the attached for a bit of info. With square waves, you can see how much it changes the wave shape, even at 80Hz. We are not using square waves, but the CSR wave form does contain many higher frequencies than 60Hz.

Try changing both channels to "DC" coupling. I think you might see a significant difference in your results.

Now, I still have to figure out why your scope is not displaying the same MEAN value regardless if CH2 is inverted or not (only the polarity should change). They should be the same, and I have confirmed this again with my measurement. The fact that yours changes tells me that there is some sort of offset somewhere that is causing an imbalance so to speak.

[gotoluc]

OK, I found the free software. It is called "Openchoice Desktop Application"
http://www.tek.com/oscilloscope/tds210-software/openchoice-desktop-application-tdspcs1-v23-0
You need to log in to download it. I am downloading now. It is 414MB. How may I get this to you?

Would it not be just as easy for me to download it then for you to upload it to a fileshare place?

So not sure what to answer on this one.

Luc