×

Detection of unsafe voltages on mobile equipment

  • US 4,791,517 A
  • Filed: 09/30/1987
  • Issued: 12/13/1988
  • Est. Priority Date: 10/03/1986
  • Status: Expired due to Fees
First Claim
Patent Images

1. Protective means for detecting the existence of an unsafe potential between earth and mobile equipment to which an AC voltage source is applied, comprising an electrically conductive member disposed between the equipment and earth, detecting means for detecting the electric field strength between the mobile equipment and earth at the location of the conductive member, the detecting means detecting the electric field strength irrespective of any earth connection or earth leakage current between the mobile equipment and earth, the detecting means deriving from said electric field strength a signal representative of the potential difference between the mobile equipment and earth, and disconnection means fed by said signal from the detecting means and operative to disconnect the voltage source from the mobile equipment when said signal corresponds to a dangerous potential of the mobile equipment with respect to earth.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×