When working with higher frequencies, such as RF, it has been suggested to utilize stranded wire when larger diameters are required. The reasoning behind this is that the RF current tends to flow on the external surface of the conductor, whereas direct current propagates through the entire cross section of the wire. Typically, this might be of consequence when sizing a ground wire for some type of apparatus. As an example, consider a 1 ft length of #12 wire:
for solid wire, the peripheral surface area for 1 foot of wire length is :
3.046 square inches
for #12 stranded wire with 7 strands, the relevant surface area is:
8.05 square inches
for #12 stranded wire with 19 strands, the area in question is:
13.25 square inches
work sheet attached ...please excuse the handwriting
for solid wire, the peripheral surface area for 1 foot of wire length is :
3.046 square inches
for #12 stranded wire with 7 strands, the relevant surface area is:
8.05 square inches
for #12 stranded wire with 19 strands, the area in question is:
13.25 square inches
work sheet attached ...please excuse the handwriting
Attachments
-
100.4 KB Views: 19