Synchronization of receiver to transmitter

• US 5,490,286 A
• Filed: 10/14/1994
• Issued: 02/06/1996
• Est. Priority Date: 09/18/1985
• Status: Expired due to Fees

• Current Assignee: Carl L.C. Kah Jr
• Original Assignee: Carl L.C. Kah Jr
• Inventors: Kah, Carl L. C. Jr.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Charouel, Lisa
• Application Number:
  US08/323,066
• Time in Patent Office: 480 Days
• Field of Search: 455/343, 455/38.1-38.3, 455/70, 455/115, 455/51.1, 455/69, 340/825.44, 340/539, 340/573
• US Class Current: 455/502
• CPC Class Codes: G08B 21/0216 Alarm cancellation after generation
• CPC Class Codes: G08B 21/0227 System arrangements with a plurality of child units
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0263 System arrangements wherein the object is to detect the direction in which child or item is located
• CPC Class Codes: G08B 21/0286 Tampering or removal detection of the child unit from child or article
• CPC Class Codes: G08B 21/0288 Attachment of child unit to child/article

Abstract

A location monitoring system is provided having a radio frequency transmitter for a person or object and radio frequency receiver for someone to monitor movement of the person or object, the receiver sounding an alarm at a predetermined time after failure to receive a signal. The transmitter is made having an intermittent transmitted signal and the receiver is made having an off-timer to coordinate with the intermittent signal, the off times saving battery power. The radio frequency receiver has an electronic switching device controlled by the radio frequency transmitter for sounding an alarm. An antenna is located in part of the carrying strap of the transmitter. The radio frequency transmitter can have various devices for sounding the alarm.

Claims

1. System for synchronizing a radio frequency receiver to be periodically OFF with a radio transmitter which is periodically ON, said system for synchronizing comprising:

the radio transmitter including a signal coding circuit having a periodically transmitted coded signal, the period of said periodically transmitted coded signal corresponding to a TRANSMITTER ON time when the periodically transmitted coded signal is generated by the radio transmitter and a TRANSMITTER OFF time when the periodically transmitted code signal is not generated by the radio transmitter; and

the radio frequency receiver, including a signal decoder circuit for decoding a received periodically transmitted coded signal, having an off-timer means which turns off the radio frequency receiver for a predetermined RECEIVER OFF time only after having received the most recent periodically transmitted coded signal, said predetermined RECEIVER OFF time being made less than said TRANSMITTER OFF time, said off-timer means being started by decoding the most recent periodically transmitted coded signal, said off-timer means automatically turning on the radio frequency receiver after the predetermined RECEIVER OFF time has elapsed to receive another periodically transmitted coded signal.

2. System for synchronizing a periodically ON radio frequency receiver with a periodically ON radio frequency transmitter, said system for synchronizing comprising:

the periodically ON radio frequency receiver having a radio frequency signal receiving circuit means for receiving an intermittent transmitted signal, the period of said intermittent transmitted signal corresponding to a TRANSMITTER ON time when the intermittent transmitted signal is generated by the radio frequency transmitter and a TRANSMITTER OFF time when the intermittent transmitted signal is not generated by the radio frequency transmitter; and

means for supplying power to said radio frequency signal receiving circuit means, said radio frequency receiver having an off-timer means which shuts off power for the radio frequency signal receiving circuit means for a predetermined RECEIVER OFF time only after having received the most recent intermittent transmitted signal, said predetermined RECEIVER OFF time being made less than said TRANSMITTER OFF time, said off-timer means being started by the most recent intermittent transmitted signal, said off-timer means automatically turning on power for the radio frequency signal receiving circuit means after the predetermined RECEIVER OFF time has elapsed to receive the next intermittent transmitted signal.

3. System for synchronizing a periodically ON radio frequency receiver including a signal decoder circuit for decoding a received transmitted signal with a periodically ON radio transmitter, said system for synchronizing comprising:

the radio transmitter including a signal coding circuit having a periodically transmitted coded signal, the period of said periodically transmitted coded signal corresponding to a TRANSMITTER ON time when the periodically transmitted coded signal is generated by the radio transmitter and a TRANSMITTER OFF time when the periodically transmitted coded signal is not generated by the radio transmitter; and

the receiver having an off-timer means which turns off said receiver for a predetermined RECEIVER OFF time, said predetermined RECEIVER OFF time being made less than the TRANSMITTER OFF time, said off-timer means being started by the most recent received and decoded periodically transmitted coded signal, said off-timer means automatically turning on said receiver after the predetermined RECEIVER OFF time has elapsed for said receiver to receive the next periodically transmitted coded signal and said receiver remaining on until said receiver receives and decodes the next periodically transmitted coded signal.

4. System for synchronizing a radio frequency receiver with a periodically ON radio frequency transmitter, said system for synchronizing comprising:

the radio frequency receiver having a radio frequency receiving circuit means for receiving an intermittent transmitted signal, the period of said intermittent transmitted signal corresponding to a TRANSMITTER ON time when the intermittent transmitted signal is generated by the radio frequency transmitter and a TRANSMITTER OFF time when the intermittent transmitted signal is not generated by the radio frequency transmitter;

means for supplying power to said radio frequency signal receiving circuit means; and

the receiver having an off-timer means which shuts off power for the radio frequency signal receiving circuit means for a predetermined RECEIVER OFF time, said predetermined RECEIVER OFF time being made less than the TRANSMITTER OFF time, said off-timer means being started by the most recent intermittent transmitted signal, said off-timer means automatically turning on power for the radio frequency signal receiving circuit means after the predetermined RECEIVER OFF time has elapsed to receive the next intermittent transmitted signal.

5. System for synchronizing a receiver monitoring system with a radio frequency transmitter, said system for synchronizing comprising:

the radio frequency transmitter including a signal coding circuit for sending out an intermittent coded transmitted signal, the period of said intermittent coded transmitted signal corresponding to a TRANSMITTER ON time when the intermittent coded transmitted signal is generated by the radio frequency transmitter and a TRANSMITTER OFF time when the intermittent coded transmitted signal is not generated by the radio frequency transmitter;

the radio frequency signal receiver including a signal decoder circuit for receiving and decoding said intermittent coded transmitted signal; and

means for supplying power to said radio frequency signal receiver, said radio frequency signal receiver having an off-timer means which shuts off power for the radio frequency signal receiver for a predetermined RECEIVER OFF time, said off-timer means being started by the most recently received and decoded intermittent coded transmitted signal, said off-timer means automatically turning on power for the radio frequency signal receiver after the predetermined RECEIVER OFF time has elapsed to receive the next intermittent coded transmitted signal transmitted after the RECEIVER OFF time has elapsed, said radio frequency signal receiver remaining on until said radio frequency signal receiver receives and decodes another intermittent coded transmitted signal at which time the radio frequency signal receiver is turned off again and the off-timer means is started again.

6. System for synchronizing a receiver monitoring system as set forth in claim 5 wherein said predetermined RECEIVER OFF time is made less than said TRANSMITTER OFF time.

7. System for synchronizing a receiver with a transmitter, said system for synchronizing comprising:

the transmitter including a signal coding circuit for sending out an intermittent coded transmitted signal, the period of said intermittent coded transmitted signal corresponding to a TRANSMITTER ON time when the intermittent coded transmitted signal is generated by the transmitter for transmission of a coded signal or pulse code and a TRANSMITTER OFF time when the intermittent cooled transmitted signal is not generated by the transmitter;

the receiver including a signal decoder circuit for receiving and decoding said intermittent coded transmitted signal; and

means for supplying power to said receiver, said receiver having an off-timer means which shuts off power for the receiver for a predetermined RECEIVER OFF time which is equal to or less than the TRANSMITTER OFF time for the pulse code of the receiver, said off-timer means being started by the most recently received and decoded intermittent coded transmitted signal, said off-timer means automatically turning on power for the receiver after the predetermined RECEIVER OFF time has elapsed and remaining on until the next intermittent coded transmitted signal is received, said receiver remaining on if said receiver does not receive and decode another intermittent coded transmitted signal, when said receiver does again receive said receiver'"'"'s matching intermittent coded transmitted signal the receiver is again turned off by said off-timer means and synchronization of the receiver to the transmitter is again established.

8. System for synchronizing a receiver monitoring system with a radio frequency signal transmitter, said system for synchronizing comprising:

the radio frequency signal transmitter sending out an intermittent transmitted signal, the period of said intermittent transmitted signal corresponding to a TRANSMITTER ON time when the intermittent transmitted signal is generated by the radio frequency signal transmitter and a TRANSMITTER OFF time when the intermittent transmitted signal is not generated by the radio frequency signal transmitter;

the radio frequency signal receiver for receiving said intermittent transmitted signal; and

means for supplying power to said radio frequency signal receiver, said radio frequency signal receiver having an off-timer means which shuts off power for the radio frequency signal receiver for a predetermined RECEIVER OFF time, said predetermined RECEIVER OFF time being made as long a period as possible consistent with the action response required of the radio frequency signal receiver, said off-timer means automatically turning on power for the radio frequency receiver after the predetermined RECEIVER OFF time has elapsed to receive the next intermittent transmitted signal from said radio frequency transmitter, said radio frequency receiver remaining on until said radio frequency receiver receives another intermittent transmitted signal at which time the radio frequency receiver is turned off again and the off-timer means is started again.