| 摘要 |
PROBLEM TO BE SOLVED: To provide a latching relay and a watt-hour meter which can determine an open/closed state and allow size reduction.SOLUTION: A latching relay comprises: an electromagnet 1 having a coil 1a and a yoke 1b; a movable contact 3 attached in the vicinity of a tip of a leaf spring 2; a fixed contact 4 which comes into contact with or separates from the movable contact; a movable-side terminal 5 connected to the leaf spring; a fixed-side terminal 6 connected to the fixed contact; engaging members 7a and 7b which are arranged between the movable-side terminal and the movable contact, and engage with each other across the leaf spring; armatures 8 which come into contact with or separate from the yoke of the electromagnet; a permanent magnet 9 arranged between the armatures; a driving piece 10 which rotates the engaging members, the armatures and the permanent magnet in an integrated manner around a rotary shaft by the action of the electromagnet so as to hold the armatures in an open-state position or a closed-state position by means of magnetic force of the permanent magnet; a magnetic sensor 14 arranged in the vicinity of the permanent magnet; and a state determination unit 13 which determines the open/closed state of the leaf spring on the basis of an output from the magnetic sensor. |
