{
  "$type": "site.standard.document",
  "description": "A security system to prevent unauthorised starting of the engine of a vehicle, comprises a remote control unit (18) equipped with a transponder which, on reception of an interrogation signal by means of at least one reception aerial (20), transmits an identification code group by means of a…",
  "path": "/patents/1109020",
  "publishedAt": "2001-10-24T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60R25/04",
    "TEXAS INSTRUMENTS DEUTSCHLAND [DE]"
  ],
  "textContent": "A security system to prevent unauthorised starting of the engine of a vehicle, comprises a remote control unit (18) equipped with a transponder which, on reception of an interrogation signal by means of at least one reception aerial (20), transmits an identification code group by means of a transmitter unit (40). Located in the vehicle is a control unit (12) which, on actuation of a starter button (26) within the vehicle, transmits the interrogation signal, and subsequently checks the identification code group transmitted by the remote control unit. Starting of the engine will only be possible when the identification code group coincides with the code group expected by it. Connected to the reception aerial (20) is a signal detector (28) which has a reaction threshold level that can be toggled between a high value and a low value. This signal detector will relay the interrogation signal to further processing stages only when the interrogation signal level exceeds the set reaction threshold. A code checking circuit (32), connected to the signal detector (28), checks the interrogation signal relayed to it as to whether it contains a pre-established code group. On recognising this code group, it switches the reaction threshold level of the signal detector (28) to the high value, whereby the code checking circuit (32) will cause the transmitter unit (40) to transmit the identification code group only when it receives the interrogation signal even after the signal detector (28) has switched to its high threshold level.",
  "title": "Security system to prevent unauthorised starting of the engine of a vehicle"
}