using a ring of magnets or the like

Patents Grantslast 30 patents

  • Information Patent Grant

    2911574

    • Patent number 2,911,574
    • Issue date Nov 3, 1959
    • H03 - BASIC ELECTRONIC CIRCUITRY
  • Information Patent Grant

    1932766

    • Patent number 1,932,766
    • Issue date Oct 31, 1933
    • H03 - BASIC ELECTRONIC CIRCUITRY
  • Information Patent Grant

    1894646

    • Patent number 1,894,646
    • Issue date Jan 17, 1933
    • H04 - ELECTRIC COMMUNICATION TECHNIQUE

Patents Applicationslast 30 patents