Thane Heins Perepiteia.

[polarbreeze]

OUR 1 K RESISTOR IS +/- 1% ACCURATE.

Thane

Thanks for that into, Thane. +/- 1% on the resistor is good enough for now. Only one more issue to resolve on the measurement and fortunately it's very easily done with gear that you surely have to hand at the U. You may have missed that point because I notice you didn't reference it.

I realize from your most recent post that you have other goals for this setup, other than demonstrating its efficiency. Those goals also require an accurate measurement of input current, so the current measurement issue jumps to the top of the priority list, I think.

The roadblock right now is that the input current readings cannot be relied upon at all because of the use of the clamp meter and because the readings are so low that they remain in the final digit of the display (note that this meter has +/- 3 digits measurement uncertainty). This can be easily resolved by removing the clamp meter and instead placing a true rms ammeter in series with the supply to the transformer (ie in the red wire that's shown in the picture passing through the clamp meter). You need to be able to resolve down to +/- 0.1mA in order to tighten up the margin sufficiently (ie +/- 1% but tighter would be even better of course). I'm sure it will be no problem to locate such a meter at the U, it's not a very demanding spec. Be sure to take your input voltage reading on the transformer side of the ammeter, not on the supply side.

Just a suggestion, hope it's useful.

PB

[OilBarren]

Wow!!!! Great job guys.

Thane,

It appears that you are now using a long thin primary. Is this part of your new success or is it just due to the lack of space?

Regards,
Larry

Ps. Thanks for the laughs, it really helps.

IF THERE IS ANY SUCCESS IT IS DUE TO LUC AND WHAT HE HAS BROUGHT TO THE LAB. HE IS MAKING IT ALL HAPPEN NOW.

THE PRIMARY IS MADE TO FIT IN A SPACE OF 1/2 cm WHICH IS AN INITIAL DESIGN FLAW ON MY PART BECAUSE I HAD NO IDEA WHAT I WAS DOING WHEN I STARTED - IT TURS OUT I AM EVEN MORE IGNORANT NOW THAN WHEN I STARTED BECAUSE I CANNOT EXPLAIN WHY THE INPUT DROPS AND ALTHOUGH I LIKE IT - IT STILL FREAKS ME OUT TO SEE IT OCCUR!

Thane

[JustMe]

I noticed something when I was working with the large hig res pics last night that I wanted to ask about.  But first I wanted to look into it some to avoid asking a totally stupid question 'cause I hate when that happens. Just hate it!   So I'm still not entirely sure if this will be helpful, but what I noticed was that the yellow meters you are using for your voltage readings and previous amp readings have amp settings from 400 microamps right up to 10A.  The meter seems to have been set at the 10A setting for the amp reading posted here before you switched to your new meter and I wondered if any of the other settings (400 mA, 40mA, 4mA, 400 microamps) would be usable and more precise as a stand in until you get you hands on whatever the best tool is? Maybe? Kinda sorta? Maybe it would just shuffle the decimal point around. Dunno. 

About 12 years ago when I was a fresh hire at the outfit I work for now I did something very bad to a multimeter.  I work in IT and for many years now I have spent the bulk of  my time in programming and web development but when I first started there I was your typical Jane of all trades. One of my occasional tasks was to assemble and/or repair coaxial cable segments for some of our networks. So I got pretty good at making good ends but once in a while something would be amiss and it would fail a resistance test and I'd have to do it again. One such day I snipped off the bad end....along with BOTH leads of the multimeter...in one fell swoop. It was the very last time I ever touched a meter, my work partner at the time made sure of that. I have of course, not yet lived that down in my department, and frankly no longer ever expect to.

[JustMe]

As per Thane's request - Photo data showing input decreasing with load.  Test #1:

[JustMe]

Test #2: