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Low-powered remote sensor and telephone line transmitter

  • US 4,691,344 A
  • Filed: 01/21/1986
  • Issued: 09/01/1987
  • Est. Priority Date: 01/21/1986
  • Status: Expired due to Fees
First Claim
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1. A data transmitter unit for transmitting data over conventional telephone lines from a remote location to a central location, the data transmitter unit deriving its operational power supply from the telephone lines to which it is interconnected, thereby doing away with the requirement for a separate power supply, the data transmitter unit comprising:

  • (a) ring detector means interconnected to the telephone line for detecting a ring signal sent over the telephone line to the remote location from the central location and actuating the unit in response thereto;

    (b) pulse rate frequency transmitter means interconnected to the telephone line for transmitting on the telephone line from the remote location to the central location pulses of a tone where the tone comnprises signals of one or more predetermined frequencies, the rate of the pulses and the one or more frequencies representing different types of data; and

    (c) charging circuit means interconnected to the telephone lines for providing power at the end of a transmission cycle to a stand-by power supply means for powering the data transmitter unit during a subsequent transmission cycle, the stand-by power supply means including capacitor means charged to a predetermined voltage.

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