| 摘要 |
A mechanism for an overload relay or the like employs a contact bar that is held in a reset position by magnetic attraction and in a tripped position by the biasing of a spring. The magnetic attraction effective in the reset condition may be overcome by a countervailing magnetic field developed by a coil driven in turn by overload sensing circuitry, or by the mechanical displacement of the contact bar away from the reset position by any small amount. Resetting is accomplished by another magnetic linkage which also may be subject to the countervailing field of the coil to prevent resetting during an overload condition.
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