FIG. 1 is a rear view of a frequency converter comprising a new, original and ornamental design;
FIG. 2 is a bottom view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a front, left side and top perspective view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a rear view of frequency converter with internal components;
FIG. 9 is a bottom view thereof;
FIG. 10 is a front view thereof;
FIG. 11 is a front, left side and top perspective view thereof;
FIG. 12 is a left side view thereof;
FIG. 13 is a right side view thereof;
FIG. 14 is a top view thereof;
FIG. 15 is a rear view of frequency converter in accordance with another embodiment;
FIG. 16 is a bottom view thereof;
FIG. 17 is a front view thereof;
FIG. 18 is a front, left side and top perspective view thereof;
FIG. 19 is a left side view thereof;
FIG. 20 is a right side view thereof;
FIG. 21 is a top view thereof;
FIG. 22 is a rear view of frequency converter of FIG. 15 shown with internal components;
FIG. 23 is a bottom view thereof;
FIG. 24 is a front view thereof;
FIG. 25 is a front, left side and top perspective view thereof;
FIG. 26 is a left side view thereof;
FIG. 27 is a right side view thereof; and,
FIG. 28 is a top view thereof.