Bifilar pancake coil overunity experiment

[ayeaye]

I don't know how an oscilloscope saves a csv data to the usb stick, so i have to guess. They mostly open the csv file in excel, so no one even knows how its written, no one opens it with a text editor, though it's a text file. The thing i may be missing, are the numbers there in quotation marks, or not. Of course it can be opened in excel, then a column copied to Trinket, though i feel it's like a kind of banal way. In any case the first two rows are likely header, and must just be omitted.

As i have seen, it's time in seconds and voltage in volts, both float numbers in the exponent form. I don't know why so, i think the time column can just be ignored, as the samples are all after regular intervals, check it, but it's almost certain. All that is necessary for the list, is the second column.

There should be only two ways how csv can be written, without quotation marks and with quotation marks. The following are the trinkets to extract the second column in both ways.

https://trinket.io/python/fbf69fdd0e

https://trinket.io/python/85ad4a832f

Then when the voltage is already in volts, there is no need to divide by 50, or whatever number of units in a scale. Because the unit already is volts. And write the y scale just 1. The x scale, when the time column is omitted, should then be the time interval between samples in us. The samples there are float as well, otherwise scale is float, and only multiplying by float makes it float.

Yes all the calculations can be done in excel the same way as in Python, you see how, and there may be a precision problem as i said. Oh well, the lame excel, but do it if you want it so. I still consider the standard to explain things, is Python. One can make a mistake in Python, where all variables are named, it is difficult to make it faultless in python, but then what about excel with its totally not intuitive a3, b4 stuff.

Tell me excel, or maybe tell me matlab. And then you effectively do it so that i cannot say anything at all. Because in what should i talk then, excel or matlab or python? I don't understand why in hell they recommend to open these csv files in excel, people for whom precision should be so important. Excel is not proper for that purpose at all.

Paste your csv file somewhere? It's a text file as i said. Or paste it into a Trinket input.txt, and post the trinket here Then i can write a script to extract data from it in an instant.

And how you likely did guess, i should post these two trinkets here, yet again. Why in hell i had to convert the input to int, there was no need to, all works the same when it's converted to float.

Trinket for the input part.

https://trinket.io/python/489cd08ab6

Trinket for the output part.

https://trinket.io/python/7a74b9bc3f

[ayeaye]

It is easy to convert CSV, if that really is a problem. No need for spreadsheet, no need for excel. I did write a Python script as you may guess, but if you don't feel like doing it. Like the following web page, choose output options, then choose only one column, and you got it. This is only one of many such online converters. Not to talk about other tools, there are a great number that can do it, CSV is so common format. It's also so terribly simple. I don't understand finding ways to go around, instead of straightforward taking CSV out of oscilloscope and directly doing calculations. It is there and it's a great thing, so why not use it.

http://www.convertcsv.com/csv-to-csv.htm

Otherwise, what do you prefer to use for calculations? Like spreadsheets, they are not precise enough as i did show earlier, excel is also not really free. Only spreadsheet calculator i found was precise enough, but i cannot provide it online anywhere, may be too minimal for you as well.

How are you going to do calculations from the oscilloscope traces?

What else can i say. In Python something is float when it is assigned a float value, that is like 0.0 instead of 0. Any expression where at least one variable or value is float, is also float. while (True): is followed by colon, it just has to by syntax. Otherwise all the statements that follow, have tab before them (indent). It is a tab that is converted to two spaces when you copy code from there, any number of spaces work instead, but there always has to be the same number. The statements that are in such way indented, are in the loop, loop ends with a statement that is less indented, and that statement is already out of the loop. Going through the loop one time, is called iteration.

You don't need to know all Python, only a small subset of it, for almost all electronics calculations that you may need to do. This small subset is almost all that one needs to know to understand these small trinkets above. Is it really so absolutely impossible to learn.

The latest scripts for input and output parts posted here again, for eternity. These are exactly the same as in the trinkets above, just posted here in case if trinkets disappear in some mysterious ways, or such.

Thank you for all your attention.

#Time scale in us
XU = 0.02
#Voltage scales of ch1 and ch2 in V
YU1 = 5.0
YU2 = 0.2
#Resistor resistance in ohms
R = 47.0
#Frequency in Hz
F = 1000.0

#In calculations XU is in ns for unit
#Voltages are in mV, scale is 50 units
XU *= 1000 / 50
YU1 *= 1000 / 50
YU2 *= 1000 / 50
e = 0.0
f1 = open("input1.txt")
f2 = open("input2.txt")
while (True):
  s1 = f1.readline()
  s2 = f2.readline()
  if (len(s1) < 2 or len(s2) < 2): break
  vs = float(s1) * YU1
  vr = float(s2) * YU2
  vl = vs - vr
  pl = vl * vr / R / 1000
  e += pl
f1.close()
f2.close()
e *= XU / 1000000
print("Input power was %.4f uW" % (F * e))

#Time scale in us
XU = 0.02
#Voltage scale in V
YU = 0.2
#Resistor resistance in ohms
R = 47.0
#Frequency in Hz
F = 1000.0

#In calculations XU is in ns for unit
#Voltages are in mV, scale is 50 units
XU *= 1000 / 50
YU *= 1000 / 50
e = 0.0
f = open("input.txt")
while (True):
  s = f.readline()
  if (len(s) < 2): break
  vr = float(s) * YU
  pr = vr * vr / R / 1000
  e += pr
f.close()
e *= XU / 1000000
print("Output power was %.4f uW" % (F * e))

[ayeaye]

Now say you get CSV from the oscilloscope, where samples (points) are already in volts, the scripts for input and output parts would be like this.

#Time between samples in ns
XU = 0.4
#Voltages are in mV
YU1 = YU2 = 1000.0
#Resistor resistance in ohms
R = 47.0
#Frequency in Hz
F = 1000.0

e = 0.0
f1 = open("input1.txt")
f2 = open("input2.txt")
while (True):
  s1 = f1.readline()
  s2 = f2.readline()
  if (len(s1) < 2 or len(s2) < 2): break
  vs = float(s1) * YU1
  vr = float(s2) * YU2
  vl = vs - vr
  pl = vl * vr / R / 1000
  e += pl
f1.close()
f2.close()
e *= XU / 1000000
print("Input power was %.4f uW" % (F * e))

#Time between samples in ns
XU = 0.4
#Voltages are in mV
YU = 1000.0
#Resistor resistance in ohms
R = 47.0
#Frequency in Hz
F = 1000.0

e = 0.0
f = open("input.txt")
while (True):
  s = f.readline()
  if (len(s) < 2): break
  vr = float(s) * YU
  pr = vr * vr / R / 1000
  e += pr
f.close()
e *= XU / 1000000
print("Output power was %.4f uW" % (F * e))

Trinkets with these scripts. Input part.

https://trinket.io/python/d99dee2247

And output part.

https://trinket.io/python/fdd30eb52e

I don't know what about this 10x attenuation by probes, i assume in the samples of digital oscilloscope this is already considered.

[F6FLT]

1)
When my bifilar coil is not connected to anything but is weakly coupled to the generator by a 2-turn loop, the resonance is around 2400 KHz.

This resonance is easily detectable, either by moving the scope probe towards the center of the coil (electric field), or by connecting the end of the probe to its ground wire and coupling this small loop to the coil (magnetic field).

This case also corresponds to the behavior of my monofilar coil.

2)
But when connecting the generator to one of the conductors at one end, and the ground to the other conductor at the other end (see diagram), the resonance drops dramatically, in my case to 28 Khz.

Surprisingly in this case of resonance, in the vicinity of the coil the probe detects the same weak electric or magnetic field as if there was no resonance.
Resonance is detected only by the increase in current supplied by the generator and by the significant voltage drop due to the overcurrent of the inrush current in the coil. We fall from 20v pp to a few hundred mV.

I confirmed this effect with a "bifilar" coil of a very different nature: an RG214 coaxial cable. The two conductors are the inner conductor and the shield, they are coupled by the 106 pF/m capacity of this type of cable. My coaxial loop is a single turn of 6m in circumference.
At the resonance frequency which is now 2550 Khz instead of 28 Khz with the other coil, the voltage drops from 20 V to 600 mV (sign that the loop has a much lower impedance than the 50 ohm of the generator), but the probe near the conductors does not detect a signal higher than what it is outside resonance.

In both cases, that of the flat coil or that of the coxial, as there is an overcurrent at resonance, at least the magnetic field should increase. But we don't detect an increase. I don't have a clear explanation for that. Does anyone have an idea?

[ayeaye]

In both cases, that of the flat coil or that of the coxial, as there is an overcurrent at resonance, at least the magnetic field should increase. But we don't detect an increase. I don't have a clear explanation for that. Does anyone have an idea?

Well, when the current increases, and the voltage on the coil decreases, then the coil consumes less energy. All current just goes through it, it is not consumed. It would be weird to expect the magnetic field to increase in that case, it would be weird if it doesn't *decrease*.

It would be interesting to see if you do input and output power calculations at resonance. Does the input power decrease at resonance? Ah yes then, but what means resonance when the input is pulse. Pulse length when the voltage on the coil is minimal?