Spole krydsvikling
spole krydsvikling er en metaltrådsviklemetode, som anvendes i radiofrekvensspoler og transformatorer i stedet for mange parallelle vindinger. Krydsviklemønsteret reducerer mængden af tråd som løber parallelt. Trådene i forskellige lag med krydsvikling krydser hinanden med stor vinkel, så tæt på 90 grader som muligt, hvilket også reducerer energitab grundet elektrisk krydskobling mellem trådene ved radiofrekvenser.[1]
Formål
Krydsviklingsmetoden anvendes til spoler designet til brug ved frekvenser fra 50 kHz og højere for at reducere to uønskede bieffekter, proksimitetseffekt og parasitisk kapacitans, som opstår i parallelle vindinger.[1][2]
Metoder
Krydsvikling kombineres ofte med litzetråd for frekvenser mellem 10 kHz - 1 MHz, en leder bestående at mange tynde individuelt isolerede tråde, hvilket yderligere reducerer tab.[3][4]
Se også
- Bifilar spole
- Ayrton-Perry vikling
Referencer
- ^ a b pa2mrx.nl: Basket/spiderweb coil design Citat: "...These coils were made because of their low own capacitance, this gives your coil a higher Q because the windings are further apart from each other, there is more air between the layers...", backup
- ^ THE SPIDER WEB (or SPIRAL) COIL, by WØXI(112613)(update 080614) Citat: "...This is accomplished by separating adjacent windings by the thickness of one winding. This separation reduces the proximity effect between wires, wherein the closer they are a current in one will increase the resistance of the other...", backup
- ^ info.ee.surrey.ac.uk: The Wave Winder, backup
- ^ info.ee.surrey.ac.uk: Power losses in wound components Citat: "...Litz (a contraction of Litzendraht)...Its purpose is to minimize the resistive losses that arise at high frequencies due to skin effect. Litz wire is mostly used within the frequency range 10kHz to 1MHz...", backup
Eksterne henvisninger
- Photo and description of basket winding Arkiveret 21. januar 2020 hos Wayback Machine
Medier brugt på denne side
(c) Glenn at the Danish language Wikipedia, CC BY-SA 3.0
Billede af ferritantenne til langbølgebåndet og mellembølgebåndet med på en ferritstav. Billedet er udgivet under GFDL.
Ferrite slug-tuned radio frequency (RF) inductor from a medium wave radio receiver. It consists of a coil of wire wound around a plastic form, which contains a threaded ferrite slug which can be screwed further into or out of the coil with a screwdriver to adjust the inductance. The wire is wound in a basket weave pattern, with adjacent layers at angles to each other, to reduce parasitic capacitance and proximity effect power losses. The wire is probably a type called litz wire, consisting of several insulated strands braided together, which reduces resistance due to skin effect.
Forfatter/Opretter: Badseed, Licens: CC BY-SA 3.0
A medium wave crystal radio receiver, manufactured by Heliogen in Germany, 1935. The coil of wire (left) is the tuning coil. It can be unplugged and replaced with different coils to cover different radio bands. It is wound in a "basket-weave" pattern to reduce resistance at radio frequencies. In front of it in the glass tube is the cat's whisker detector, consisting of a crystal of galena touched by a fine wire, which extracts the audio signal from the radio frequency carrier wave. In front of that is the tuning knob, connected to an adjustable capacitor which is used to tune in different stations.