Research website of Vyacheslav Gorchilin
2020-02-07
All articles / Experiments
A simple method to detect the displacement current in the capacitor
Despite the rapid development of electronics and electrical engineering, the displacement currents are still poorly known [1], and mostly theoretical conclusions from Maxwell's equations. This is largely due to the difficulties of staging experiments in its detection, so at the moment, such studies are very few [2-4]. In this experiment, we again almost confirm the existence of the displacement current and take another step towards the realization is theoretically developed by impulse technology.
The author managed to set up an experiment and get proof of the bias current with a fairly simple device consisting of capacitors FGT-AND [5], and wound on reels (Fig. 2-3), which we further call katushka-capacitor, and on the diagram (Fig. 1) will be denoted by CL1. This figure shows the diagram of replication, where the generator of short pulses GG1 periodically closes the circuit load, consisting of katushka capacitors CL1 and depending on experience, parallel to it included the R1 resistor or the inductor L1. CL1 at the standard condenser insights, there are two more output with a wound on his coils, which are connected to a diode bridge, and he to svetovodnoy the matrix HL1, designed for a voltage of 12 V. On the power supply circuit is mounted a smoothing capacitor C1, and the gap plus wire installed ammeter constant current I1.
Fig.1. The experimental setup for the detection of the displacement current in the capacitor
For sufficiently short pulses from GG1, matrix HL1 steadily glowed. The author of the pulse duration, which was observed this effect was approximately 140 NS, and if this value increases, the matrix went out, despite the fact that the current power supply, controlled by the ammeter, I1, is increased. Very interesting also was the fact that the load in the form of a matrix (and any other, up to the full circuit) does not affect the current consumption!
Thus, the effect observed under different types of loading. In figure (1a), parallel to CL1 included ordinary resistor, while figure (1b) is a choke. Effectively, of course, was the second option.
The part and setting
The main part of this experiment, katushka-capacitor. It is very simple: on a porcelain dielectric capacitor FGT-winded AND 14-16 turns of insulated wire with a core diameter of 0.8-1.2 mm (Fig. 3), findings which further poluchajutsja to the diode bridge VD1. From the author it was a capacitor of 10 nF and 15 kV, but you can choose any other similar [5].
Fig.2. FGT-AND 10 nF, 15 kV
Fig.3. Katushka-capacitor CL1
Inductor L1 must be low capacitance. It can be done on a ferrite ring permeability 1000NM and higher, winding him 10-15 turns of insulated wire with a diameter of 0.2-0.4 mm. it is Important that the coils were wound one by one, without overlap. The whole winding should be placed in a single layer.
The diode bridge VD1 should consist of four fast high voltage diode such as UF4007, and the led matrix with the parameters of 12 V and 10 W, or similar.
The generator must give short pulses with a duration of 140 NS, and the frequency can range from 40 to 150 kHz depending on load. The duration and frequency need to be selected individually under high illumination led matrix. Very important here is the output of the key generator which should be fast enough. The author proposed here, the effect is good and stable was only observed with the transistor TF27S60 (AOTF27S60).
Insights
One of the assumptions that can rightly occur to readers is that the wire wound on the capacitor dielectric, is equivalent to passing parallel to the axis of the capacitor conductor, which may be induced by a magnetic field. Ie in fact — to be a normal transformer. To test this hypothesis the author conducted another additional experiment in which the dielectric of the capacitor was wearing an open coil of the copper foil to two opposite sides (along the axis) which ends was connected a low power led is 1.5 V. Therefore tested the equivalent of the conductor extending parallel to the axis of the capacitor. The led was not observed at any values of the pulse duration or frequency. Also, especially increased voltage power source. The result was all negative. Therefore, the version of the transformer, if there is to be, that in itself is minor, and not critical for this experiment, as.
The following argument in favor of the current detection bias is the fact that increasing pulse duration from GG1 whole effect disappears and HL1 ceases to glow.
The author believes that the main argument which proves that is a fixation bias current, is the lack of reaction of the primary circuit in the secondary. Namely, even with complete closure of the input or output of the diode bridge VD1, the consumption scheme, which is controlled by the ammeter I1, is not affected.
The materials used
  1. Wikipedia. Current offset.
  2. Experiments on the detection and study of the displacement currents in a vacuum.
  3. V. S. Gudymenko, V. I. Piskunov. Experimental verification of the existence of a magnetic field generated by the bias currents of the capacitor.
  4. Zadorozhnyi V. N. Bias current and magnetic field.
  5. Capacitor FGT-AND.