I can't for the life of me, figure out what these diagonal rectangles are...

a busy cat


  • 6
    \$\begingroup\$ FB = Ferrite beads? \$\endgroup\$ – Dan Laks Oct 27 '14 at 18:53
  • 1
    \$\begingroup\$ yeah, Ferrite Bead with 2A ratings. \$\endgroup\$ – KyranF Oct 27 '14 at 19:20
  • \$\begingroup\$ Are you referring to FB10 & FB12 or to J6 which is probably some sort of edge connector. Where did you find the image? \$\endgroup\$ – jippie Oct 27 '14 at 19:30
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    \$\begingroup\$ @jippie J6 is almost certainly a typical pin and barrel power connector, with an optional switched contact on the barrel that has been shorted and ignored in this application. \$\endgroup\$ – RBerteig Oct 27 '14 at 23:35
  • \$\begingroup\$ possible duplicate of Meaning of FB symbol in schematics? \$\endgroup\$ – Makyen Dec 15 '14 at 6:46

Those are ferrite beads, rated at 50 \$\text{m}\Omega\$ DC resistance and 2A. At low frequencies, they are predominantly inductive, but become more resistive (lossy) at high frequencies. They are very useful tools for electromagnetic compatibility. They come in surface mount packages, like what is most likely intended for that schematic, as well as clamp-ons for cables.

  • \$\begingroup\$ Rated for 2A and with a resistance of 0.05 ohm. \$\endgroup\$ – Ignacio Vazquez-Abrams Oct 27 '14 at 18:54
  • \$\begingroup\$ That's 0.05Ω at DC (0Hz). \$\endgroup\$ – Majenko Oct 27 '14 at 19:01
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    \$\begingroup\$ The symbol is probably supposed to look like the edge view of a toroidal ferrite core with a wire threaded through it. \$\endgroup\$ – Spehro Pefhany Oct 27 '14 at 19:26

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