Oh geeze, 20 nanohenries as measured on a digibridge.
Ed, what is resolution and accuracy of the test setup? Are you looking at the Least Significant Digit again (LSD)?
What did the resistor measure for inductance.
What does a straight wire measure for inductance?
What was the test frequency?
John
Oh geeze, 20 nanohenries as measured on a digibridge.
Ed, what is resolution and accuracy of the test setup? Are you looking at the Least Significant Digit again (LSD)?
What did the resistor measure for inductance.
What does a straight wire measure for inductance?
What was the test frequency?
John
My bad .00020 mH for the DUT .00018 mH for the same length wire. What do you expect for 3" of wire?
Ah, someone else noticed the subtly stated swap of the control.
Always nice to have an honest R&R for a measurement before thinking it's significant. Especially when critical details like procedure and layout are omitted...
Ah, someone else noticed the subtly stated swap of the control.
Always nice to have an honest R&R for a measurement before thinking it's significant. Especially when critical details like procedure and layout are omitted...
You know for a guy who is so often wrong, you do like to cast aspersions. Why don't you try asking a question if the pictures are not clear to you?
But personal attacks when you are wrong seems to be your specialty.
So you don't have any questions, do you just want to be nasty? Or can you really not read basic oscilloscope results?
I know you tried to measure Bybees with the intention of disproving any results and claiming fraud, but your measurements could not even tell the difference between resistor types. You also never even tried them as non RLC filters which is the claim.
You could of course try something useful like doing the same simple setups I show and seeing what results you get.
Actually I do the posting from my office and didn't want to go in late. (Or early depending on your point of view and time zone.)
So no R&R, no details on setup, procedure, or analysis. No prob, have fun running suckers down the rathole.
I wondered what all this was about, thinking a "bybee" was from the lab of Dr Loof Lirpa maybe... But after a check with google, I see it's a "quantum purifier".
Probably works well in combination with Quantum Clip
Probably works well in combination with Quantum Clip
A wire does not have external inductance. It will have an internal 15 nH per foot at DC, and will reduce to zero at high frequency depending on the conductor diameter. (I assume a cylindrical conductor with a permeability of 1). edit: speaking of which, is the bybee lead magnetic?
A loop of wire is required in order to read inductance. Therefore, your question can have no answer. The external field based inductance of any conductor is dependent on the return current path.
What was the frequency of test? If you are at 1Khz, your equipment will have no accuracy nor repeatability at that level of inductance.
Ed, I haven't found any captions to any of your test pics, how does one identify the bybee vs a resistor?
What current probe did you use?
How do you control the conductor location within the current probe, as there is a sensitivity to the wire position in any probe.
For any measurement of this type, your setup as pictured is useless for a rigorous analysis as it does not allow duplication by another.. A bowl of spaghetti cannot be considered an adequate test fixture, as nobody can duplicate it.
Proximity of the dut to the probe is a big no-no.
You've not eliminated magnetic coupling of any of your wires, have taken no control of that aspect, which is very important when it comes to any magnetic measurement, especially more so when dI/dt measurements are tried in a low impedance circuit.
What measures did you take to isolate the scope ground from the noise you are creating on the line?
John
Edit...oh, BTW, you know the coil in the wire nuts are probably magnetic, right? everybody knows that a bybee can only absorb only so many antispin electrons created by wirenut coil magnetic permeability rotation before the device saturates..meaning that the devices need to be cryogenically reconditioned at 77K (minimally) while pulsing it with current.
Last edited:
JN
The wire measures very close to the same as the DUT, at the frequencies and impedances the inductance will have virtually no effect. Al that matters is they are extremely close, as is the resistance. As the DUT is a bit bigger than the wire there will be a bit more capacitance.
If the test is at 1,000 hertz and the data is in the same range, I don't see that as an issue.
The way to identify what is shown is to hold your mouse cursor over the image, it will then show the title.
I used my own little toroid based current transformer into the 50 ohm scope input. Same as my other diode switch tests. The probe fits tightly to the wire at 3" from the DUT.
The test fixture is a PC card, the mess is the transformer wires. I have used the fixture for a number of tests (Mostly diode switching) with stable results over the years.
My bench is on an isolated line with filters and the gear sees a reasonably clean power line. The noisy AC line is also special and isolated from the rest of the shop otherwise those D spikes show up everywhere.
I have not included any analysis just showing my measurements.
Now the experienced will see the diode spikes, line noise during the diode conduction, diode cutoff and the buzzer spikes.
There are multiple runs because with noise the data gets a bit obscured.
The DUT runs are interspersed.
I am curious to see if anyone will actually do measurements on the data and chart it.
When testing anything at or below 1 uH, the first thing you do is place a simple short across the test terminals and start the "autocal" or "zero cal" function. This eliminates the physical loop between test points from the measurement. As such, the only viable inductance measurement is the relative inductance difference between a short, and the unit under test.
You are reporting data which is well into the error band and resolution limits of the test instrument, and present data as absolutes rather than relative. While I can appreciate the fact that you gave the numbers, they are in fact, useless.
Resolution and accuracy of a test is the entire ball of wax. Without an accurate understanding of both issues, or in this case without regard to the accuracy of the measurements, the data presented is useless as a metric.
If you had auto-zero'd and tested the bybee on a good meter that goes either 10Khz or 100 Khz, you may actually have shown a difference.
Ah, thanks. I didn't wait for the name to pop up, impatient as I am...
Neat. The pic seems to show it up against the DUT.
Cautions:
When making a current transformer like that, you have to make sure that wire position within the toroid doesn't change the reading sensitivity. We have that issue here, and have to maintain centrally located wires within the toroids. As well, external currents in the local area will alter the accuracy as well, which is why I pointed out the other wires in the pic.
The tightness of the pickup coil will alter the parasitics, and the spacing can allow some of the dut flux to run in the parasitic space. The pickup is relying on the flux through the ferrite, not the parasitic path.
The permeability of the DUT wire through the toroid will also alter the reading, as will that wire outside the dut, so entrance and exit angles are important.
It's nice to see the work, thanks. That won't stop me from pointing out error sources however...no get outta jail passes from me..
John
JN
You should look at the General Radio patents on the Digibridge. I think you'll find their technique interesting. Lost the cite, but I suspect you can find it.
My next test will be to use more than one Bybee. If they are doing something the effect should increase. Will post this next Bybee day. (4/1/2017)
I am just finishing up my next low noise preamp. It should get down below 20 pV/rt Hz.
You should look at the General Radio patents on the Digibridge. I think you'll find their technique interesting. Lost the cite, but I suspect you can find it.
My next test will be to use more than one Bybee. If they are doing something the effect should increase. Will post this next Bybee day. (4/1/2017)
I am just finishing up my next low noise preamp. It should get down below 20 pV/rt Hz.
There are some SQUID flux nulling voltmeters down at the 2-3pV level but they need 77K. What did you do buy a whole wafer of those op-amps?
There are some SQUID flux nulling voltmeters down at the 2-3pV level but they need 77K. What did you do buy a whole wafer of those op-amps?
Nah, an input transformer with a DC compensation winding. (With 100 op amps and a multiplier)
- Status
- Not open for further replies.