| 摘要 |
An electrical contactor 10 comprises a terminal 12 having a fixed member 30 and a fixed electrical contact 32; and a second terminal 14 connected to a busbar 16. At least two electrically-conductive movable arms (fig 3a, 58, 60) connected to the busbar 16, have a movable electrical contact 50 and are preformed and preloaded so that biased-closed movable arm 58 is biased towards the fixed electrical contact 32 in the absence of a separating force, and biased-open movable arm 60 is biased away from the fixed electrical contact 32 in the absence of a closing force. The movable arms 58, 60 and the busbar 16 are arranged so that when the contacts close contra-flowing current urges the movable arms 58, 60 towards the fixed member 30 to increase force between the contacts. A contactor may also comprise a fixed electrical contact 32, a movable electrical contact 50, an electrical actuator 64 having a drive coil 80 to open and close the contacts, and a power supply that outputs truncated-waveform drive pulses (fig 5) to the electrical actuator means 64, so as to prevent contact separation prior to peak load current. A reverse flux may be induced in a second actuator feedback coil to control a delay of contact opening and closing relative to an AC waveform zero-crossing, to control contact bounce and reduce arc duration. |
