Transmitter detector for use in a moving vehicle
First Claim
1. Apparatus for detecting the proximity of a radio transmitter of known frequency and power to a moving vehicle, comprising:
- a radio frequency scanner having a selected channel set to said known frequency so that it provides a channel active signal during the time that a signal is received on said known frequency;
timing means responsive to said channel active signal for generating a timing delay signal having a duration representative of the maximum time for said moving vehicle to pass said transmitter based on an estimated speed of said vehicle and the range of said transmitter; and
alert means responsive to said channel active signal and said timing delay signal for generating an operator alert during said channel active signal and during said timing delay signal.
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Accused Products
Abstract
Detection apparatus for alerting an operator of a moving vehicle to the proximity of a radio transmitter of known frequency and power, typically in a police vehicle. The detection apparatus includes a scanner radio having a selected channel set to the know frequency so that it provides a channel active signal during the time that the police vehicle transmitter is on. The detection apparatus further includes a timing circuit for generating a delay interval representative of the maximum time for the moving vehicle to pass the police vehicle and circuitry for generating a visual and/or audible operator alarm during the channel active signal and during the delay interval. The scanner radio is also utilized to monitor voice transmissions between the dispatcher and the police vehicle, thereby providing the vehicle operator with additional information regarding nearby police vehicles. In an alternative embodiment, a single frequency radio receiver is utilized to provide a visual and/or audible operator alarm and can also be utilized to monitor voice transmissions on the known polic vehicle frequency.
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Citations
22 Claims
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1. Apparatus for detecting the proximity of a radio transmitter of known frequency and power to a moving vehicle, comprising:
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a radio frequency scanner having a selected channel set to said known frequency so that it provides a channel active signal during the time that a signal is received on said known frequency; timing means responsive to said channel active signal for generating a timing delay signal having a duration representative of the maximum time for said moving vehicle to pass said transmitter based on an estimated speed of said vehicle and the range of said transmitter; and alert means responsive to said channel active signal and said timing delay signal for generating an operator alert during said channel active signal and during said timing delay signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Apparatus for detecting the presence of a radio transmitter of known frequency and power within a predetermined distance of a moving vehicle, said apparatus comprising:
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radio receiver means for receiving a signal from said radio transmitter and providing a received signal; signal detector means responsive to said received signal for providing a channel active signal during the time that said received signal exceeds a prescribed level; timing means responsive to said channel active signal for generating a timing delay signal having a duration based on an estimated speed of said vehicle relative to the power of said transmitter; and alert means responsive to said channel active signal and said timing delay signal for generating an operator alert during said channel active signal and during said timing delay signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. Detection apparatus for modification of a radio receiver to detect the presence of a radio transmitter of known frequency and power within a predetermined distance of a moving vehicle, said apparatus comprising:
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sensing means responsive to a received signal from said radio receiver for providing a channel active signal when said received signal exceeds a prescribed level; timing means responsive to said channel active signal for generating a timing signal having a duration based on an estimated speed of said vehicle relative to the power level of said transmitter; and alert means for generating an operator alert during said channel active signal and said timing signal. - View Dependent Claims (22)
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Specification