{
  "$type": "site.standard.document",
  "coverImage": {
    "$type": "blob",
    "ref": {
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  "description": "A motor driving device according to the present invention includes: a PWM duty ratio detecting unit for detecting a target rotational speed based on a duty ratio of a PWM signal input from a host system; a PWM period detecting unit for detecting a period of the PWM signal; a PWM period error…",
  "path": "/patents/973126",
  "publishedAt": "2014-07-02T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60L50/15",
    "PANASONIC CORP [JP]"
  ],
  "textContent": "A motor driving device according to the present invention includes: a PWM duty ratio detecting unit for detecting a target rotational speed based on a duty ratio of a PWM signal input from a host system; a PWM period detecting unit for detecting a period of the PWM signal; a PWM period error calculating unit for calculating an error between a PWM period output from the PWM period detecting unit and a PWM period previously set as a reference calculated by using the operational clock generator; a position detecting sensor for detecting a permanent magnet of the rotor; and an actual rotational speed calculating unit for calculating an actual rotational speed of the rotor by using a signal output from the position detecting sensor. The present motor driving device controls a speed while correcting the actual rotational speed based on the PWM period error.",
  "title": "MOTOR DRIVING APPARATUS AND BRUSHLESS MOTOR"
}