Talk:Displacement current/Archive 3

message: I would be interested to know if any one has any ideas on how to measure displacement current in an air spaced capacitor. My only stipulation is that the procedure must not use the measuremrent of any magnetic field to infer the displacement current. 
This is because Im trying to prove that there is no current, not that there is no magnetic field.  The presence of magnetic field will not be taken as evidence of displacement current. Suggestions welcomed here!--Light current 02:19, 25 December 2005 (UTC)
thread_title:  Experiment to measure displacement current in a parallel plate capacitor, or a [[transmission line]] equivalent 

message: Seen on the web:(Possible **crank** alert!)
A Problem With Ammeters and Measurement of dØ/dt
Note that an ammeter cannot differentiate between displacement current dØ/dt and normal current dq/dt. In the ammeter, the sample dØ/dt will couple to free electrons, producing a normal dq/dt inside the ammeter. The driving of this dq/dt through a precision resistance, e.g., is measured and the instrument is calibrated to show the dq/dt amperes flowing. One of the major needs of free energy researchers is the development of a good current meter that will differentiate between dØ/dt and dq/dt, and measure each one. Short of using a mass spectrometer to differentiate the mass current  dm/dt, and comparison of those mass current measurements with an ammeter's measurements of the "current" dq/dt, and calculating the dØ/dt from that, I presently know of no way to precisely and simply measure and separate the two current components. I have been thinking of utilizing a multi-channel sampling meter set arrangement, where one channel uses a dm/dt  blocking device such as the Fogal semiconductor in this respect, but have not yet developed the complete concept. Tom Bearden??
--Light current 19:30, 11 January 2006 (UTC)
thread_title:  Difficulties in measurement of 'displacement current' 

message: Rather than write a book about what I did, I’ll answer specific questions as they arise. I’ll give the numbers and some calculations here.
I built the air gap capacitor out of two 24mm x 75mm stainless steel plates. I separated them with a 0.8mm thick polyethylene washer and bolted the plates together with Teflon nuts and threaded rods.   
For the experiment, I drove the capacitor with an RF amplifier in series with an impedance matching transformer. The output of the transformer is connected directly across the capacitor. The current transformer is placed around the ground lead to the capacitor; the voltage probe is touching the opposite lead. 
Assuming a parallel plate capacitor, the capacitance should be 8.85e-12*1.8e-3/0.8e-3=20 pF. This is confirmed by putting the device in an LCR meter.    
I drove the capacitor at 500 kHz. The calculated impedance magnitude is 15.9 kOhm. The current and voltage traces are shown first. The traces come directly from the oscope. Yellow is voltage and blue is current (1V=1A). 
Numerically integrating the current waveform gives the total charge transferred. The charge trace is the magnitude of charge on the bottom plate plus the top plate. 
First, the impedance of the capacitor is measured. One approximation is to take the peak magnitude of the voltage and divide by the peak magnitude of the current. As shown in the waveforms, my amplitude is not constant over time, so this might introduce some error. Vpeak/Ipeak=1060V/.074A=14.3 kOhms.
At the peak voltage, we can look at the charge on the capacitor plate. The max total charge is 50.87 nC, therefore the charge on one plate is 25.44nC. The charge density on one plate is equal to the average electric flux density between the paltes. Q/A=14.13 microC/m^2. Dividing this by the permittivity of free space gives the average electric field, 1.59 MV/m. Multiplying this by the gap distance gives the expected voltage across the plates, 1.28kV.
Using the parallel plate approximation for the capacitor, the measured charge gives a voltage that is within <20% of the measured voltage across the capacitor. My goal was to show that the conduction current measured in the leads is equal to the displacement current in the capacitor. This was done by showing charge transfer and its relation to the E and D fields. Any additional info I'll be happy to add. Mak17f 19:16, 8 March 2006 (UTC)
thread_title:  Results 

message: I have just realised that the insertion of a resistive sheet between the plates will intercept some of the em wave and act like any other series resistor in the cct. There will therefore probably be some pd measured across it. So another way of determining the presence of any 'interplate' current needs to be found. I dont know if there is a reliable method that doesnt give spurious answers. Anyone have any suggestions? --Light current 03:11, 11 March 2006 (UTC)
thread_title:  Experimental difficulty