Warning method and apparatus and parallel correlator particularly useful therein
First Claim
1. Apparatus for monitoring a particular location for the occurrence of a predetermined condition thereat, comprising:
- a transmitter located at the monitored location for normally transmitting a series of first electrical signals at a predetermined repetition rate and in a predetermined time slot;
a receiver for receiving said first electrical signals;
a sensor for sensing the predetermined condition;
a signalling device;
control means effective, upon sensing the predetermined condition, to interrupt the transmission of said first electrical signals at said predetermined repetition rate to indicate that the predetermined condition has occurred, and to initiate the transmission of a series of second electrical signals at the same repetition rate as said first electrical signals to identify the predetermined condition that has occurred;
and a logic circuit for automatically enabling said receiver to receive said first and second electrical signals transmitted by said transmitter just before their expected arrival time, and disabling said receiver from receiving said first and second electrical signals just after their expected termination time.
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Accused Products
Abstract
A method and apparatus for monitoring a particular location for the occurrence of a predetermined condition, such as fire, smoke, gas, etc., involves continuously transmitting, from a transmitter located at the monitored location, to a receiver, a source of electrical signals at a predetermined repetition rate having a period less than the interval between the electrical signals by at least one order of magnitude, and interrupting the transmission of the electrical signals upon sensing the predetermined condition. For example, the transmitted electrical signals may be coded bursts of pulses having burst periods of the order of milliseconds or nanoseconds, and spaced intervals of the order of seconds. Also, described is a parallel correlator which may be used as the decoder.
70 Citations
20 Claims
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1. Apparatus for monitoring a particular location for the occurrence of a predetermined condition thereat, comprising:
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a transmitter located at the monitored location for normally transmitting a series of first electrical signals at a predetermined repetition rate and in a predetermined time slot; a receiver for receiving said first electrical signals; a sensor for sensing the predetermined condition; a signalling device; control means effective, upon sensing the predetermined condition, to interrupt the transmission of said first electrical signals at said predetermined repetition rate to indicate that the predetermined condition has occurred, and to initiate the transmission of a series of second electrical signals at the same repetition rate as said first electrical signals to identify the predetermined condition that has occurred; and a logic circuit for automatically enabling said receiver to receive said first and second electrical signals transmitted by said transmitter just before their expected arrival time, and disabling said receiver from receiving said first and second electrical signals just after their expected termination time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification