{
  "$type": "site.standard.document",
  "description": "A protection and control system incorporates status acquisition apparatus (100) for use in monitoring the status of a device in the protection and control system, such as a protection relay in a high voltage electrical circuit. The status acquisition apparatus comprises an conversion circuit (101)…",
  "path": "/patents/1110518",
  "publishedAt": "2001-09-05T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "H02H1/0038",
    "ALSTOM [FR]"
  ],
  "textContent": "A protection and control system incorporates status acquisition apparatus (100) for use in monitoring the status of a device in the protection and control system, such as a protection relay in a high voltage electrical circuit. The status acquisition apparatus comprises an conversion circuit (101) which converts an input voltage to a pulse width modulated signal and a comparison circuit (103) which monitors the pulse width modulated signal to determine the status of the device. The mark-space ratio of the pulse width modulated signal decreases as the input voltage is increased to minimise power dissipation over a range of input voltages. The status acquisition apparatus may form an integral part of a protective switching device, although other applications are envisaged.",
  "title": "Electrical protection and control system"
}