STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

broli · June 17, 2010, 02:31:03 PM

I forgot to ask to take pictures of the disassembly process. Is this an E core? Were all windings were around the center E finger? So if I'm right you removed the spool from the E core and then tested it and saw OU. Then unwound the wires and rewound it on the same spool and saw UU? Since these transformers are very cheap I recommend you buy a lot. And check a few of them to confirm it, and maybe other models too? Then work as a surgeon to find out just how they are wound

.

Omnibus · June 17, 2010, 02:39:58 PM

Quote from: broli on June 17, 2010, 02:31:03 PM
I forgot to ask to take pictures of the disassembly process. Is this an E core? Were all windings were around the center E finger? So if I'm right you removed the spool from the E core and then tested it and saw OU. Then unwound the wires and rewound it on the same spool and saw UU? Since these transformers are very cheap I recommend you buy a lot. And check a few of them to confirm it, and maybe other models too? Then work as a surgeon to find out just how they are wound .

Yes, you've understood it correctly. It's an EI core and I removed it just the way @LarryC instructed. I tried to get more of these yesterday but all the RadioShacks in the whole Boston area are out of stock, I was told. Now I'm going out with the same mission--hope they've replenished their inventory. Too bad I'm not in New York right now. There are at least 6 RadioShacks' in the neighborhood. Will soon make a new report because I just took apart another one of the fast draining supply of the apparently most precious item RadioShack has.

Omnibus · June 17, 2010, 02:59:54 PM

@broli,

Let me mention something before I go. I just tried the newly dismantled transformer (having it only as an air core) and, suddenly, I'm getting underunity--the voltage leading the current and so on. I look at the setup and what do I see, I've connected the black wire which is the midpoint. So, I promptly corrected that and we're back in business--current leading the voltage and the OU is 2.11. No metal core, mind you. Be back in a bit.

teslaalset · June 17, 2010, 03:56:15 PM

@Omnibus
Sorry for stepping in without any feedback, I have been following your postings thought, but did not want to interfere due to different opinions.

I just want to check some of your remarks, which seem very essential to me.
You mentioned that you've got a COP > 1 when current is leading the voltage.
Are you saying that this is the essential condition to get OU in this setup?

Omnibus · June 17, 2010, 05:19:27 PM

Quote from: teslaalset on June 17, 2010, 03:56:15 PM
@Omnibus
Sorry for stepping in without any feedback, I have been following your postings thought, but did not want to interfere due to different opinions.

I just want to check some of your remarks, which seem very essential to me.
You mentioned that you've got a COP > 1 when current is leading the voltage.
Are you saying that this is the essential condition to get OU in this setup?

This is a very good question. I thought so but if you look at the I-V phase shift vs. frequency diagram I posted yesterday you'll notice that the current starts leading the voltage at around 9kHz frequency which is much earlier than the frequency of 190kHz where the OU kicks in. Nevertheless, I think I leading V is one of the conditions for OU.