{
  "$type": "site.standard.document",
  "coverImage": {
    "$type": "blob",
    "ref": {
      "$link": "bafkreibv66sgulw73chgyjdfocijiy7qtb5ledp564ch3hy3jreo6un3du"
    },
    "mimeType": "image/png",
    "size": 97933
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  "description": "It is possible to monitor the state of each on/off mechanical contact or on/off semiconductor device of a motor contactor and brake contactor of a driving circuit supplying driving electric power to a three-phase alternating-current electric motor and a brake of an electric lifting-lowering device…",
  "path": "/patents/987845",
  "publishedAt": "2013-08-07T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01R31/26",
    "KITO KK [JP]"
  ],
  "textContent": "It is possible to monitor the state of each on/off mechanical contact or on/off semiconductor device of a motor contactor and brake contactor of a driving circuit supplying driving electric power to a three-phase alternating-current electric motor and a brake of an electric lifting-lowering device through the motor contactor and the brake contactor, respectively, and to detect a reverse phase of three-phase alternating current before the contactor is turned on. Detecting circuits 6a to 6e are connected in parallel to respective on/off mechanical contacts or on/off semiconductor devices of a motor contactor 2 and/or a brake contactor 4 of a driving circuit supplying driving electric power from a three-phase alternating-current power supply circuit 1 to a three-phase alternating-current electric motor 3 and a brake 5 through the motor contactor 2 and the brake contactor 4, respectively. The detecting circuits output pulse signals synchronized with the alternating current from the alternating-current power supply circuit. A signal processing circuit 7 processes the pulse signals from the detecting circuits and detects a normal or abnormal condition of each on/off mechanical contact or on/off semiconductor device of the motor contactor and/or the brake contactor.",
  "title": "ELECTRIC WINCH ELEVATOR DEVICE DRIVE CIRCUIT FAULT INSPECTION DEVICE"
}