Inductive coupling system for the bi-directional transmission of digital data

Claim 2

A bi-directional data transmission system comprising: (a) a single, saturable inductive coupling means for transmitting a first signal in a first direction from a first unit to a second unit via said inductive coupling means and a second signal in a second direction from said second unit via said inductive coupling means to said first unit; (b) said first unit comprising first means for generating and applying said first signal to said inductive coupling means, said first signal comprising a series of pulses, each pulse defining a transmission interval for the transmission of said second signal in said second direction, said transmission interval being of a sufficient length to permit said inductive coupling means to de-saturate to a level to permit efficient transmission of said second signal; and (c) said second unit comprising second means responsive to the occurrence of a transmission interval defining pulse at said inductive coupling means for generating and applying said second signal to said inductive coupling means to be transmitted thereby during said defined transmission interval.

Claim 3

The bi-directional data transmission system as claimed in claim 1, wherein each transmission interval pulse has a width defining the interval for the transmission of said second signal in said second direction.

Claim 4

The bi-directional data transmission system as claimed in claim 1, wherein said first generating means generates said first signal as a train of regular clock pulses, said first generating means modulating selected of said clock pulses said to define the transmission interval.

Claim 5

The bi-directional data transmission system as claimed in claim 3, wherein said first generating means comprises means for selecting clock pulses of said first signal and for controlling the pulse width of said selected clock pulses to define the interval for the transmission of said second signal, said pulse width of said transmission interval defining pulses being greater than the pulse width of the remaining of said clock pulses of said first signal.

Claim 6

The bi-directional data transmission system as claimed in claim 3, wherein said second generating means comprises clock detect means responsive to the presence at said inductive coupling means of said regular clock pulses of said first signal to generate a third clock signal.

Claim 7

The bi-directional data transmission system as claimed in claim 5, wherein said second generating means comprises means responsive to said third clock signal for processing said second signal in synchronism with said third clock signal.

Claim 8

The bi-directional data transmission system as claimed in claim 5, wherein said second generating means comprises data transmission means for receiving said first signal appearing at said inductive coupling means and for selectively responding to said transmission interval pulses for transmitting said second signal during said defined transmission intervals.

Claim 9

The bi-directional data transmission system as claimed in claim 5, wherein said second unit comprises means for modulating said second signal with data.

Claim 10

The bi-directional data transmission system as claimed in claim 8, wherein said data modulating means comprises means for generating a high frequency signal of a frequency greater than that of said third clock signal and means responsive to the data for selectively providing said high frequency signal.

Claim 11

The bi-directional data transmission system as claimed in claim 9, wherein said second unit is responsive to said transmission interval pulses for applying said high frequency signals during said defined transmission intervals.

Claim 12

The bi-directional data transmission system as claimed in claim 1, wherein said first unit includes means for modulating said first signal with data to be transmitted to said second unit, and said second unit comprises means for demodulating said first signal.

Claim 13

The bi-directional data transmission system as claimed in claim 1, wherein said first generating means generates said first signal as a sequence of regular clock pulses and said first unit comprises means for modulating selected of said regular clock pulses with data to be transmitted to said second unit, and said second unit comprising means for detecting said selected modulated signals and for demodulating said detected modulated signals to derive an output indicative of the transmitted data.

Claim 14

The bi-directional data transmission system as claimed in claim 12, wherein said modulating means pulse width modulates said selected clock pulses.

Claim 15

The bi-directional data transmission system as claimed in claim 13, wherein said bi-directional data transmission system is operative in a first, data transmit mode and in a second, data receive mode, said first generating means operative in said first mode for selecting ones of said clock pulses to define said data transmission interval and said modulating means operative in said second mode for selecting and modulating selected ones of said clock pulses with data to be transmitted to said second unit.

Claim 16

The bi-directional data transmission system as claimed in claim 14, wherein said second generating means is responsive in said first mode to said transmission interval defining pulses for transmitting said second signal from said first unit to said second unit.

Claim 17

The bi-directional data transmission system as claimed in claim 15, wherein said detecting and demodulating means is operative in said second mode for detecting and demodulating said selected modulated pulses of said first signal to provide an output indicative of the data.

Claim 18

The bi-directional data transmission system as claimed in claim 3, wherein said second unit comprises power conversion means for receiving said regular clock pulses and for utilizing at least one of said clock pulses to solely energize said second unit.

Claim 19

The bi-directional data transmission system as claimed in claim 17, wherein said second unit comprises non-volatile memory means for storing data and means responsive to said clock pulses of said first signal for reading out and for transmitting said stored data via said inductive coupling means during said defined transmission intervals.

Claim 20

The bi-directional data transmission system as claimed in claim 18, wherein there is included meter means responsive to utility consumption for generating pulse-like, electrical signals, each indicative of the consumption of a given quantity of the utility, said non-volatile memory means for storing an indication of the number of the pulse-like, electrical signals generated by said meter means, said indication indicative of the total measured utility consumed, said power conversion means responsive to each of said pulse-like, electrical signals to energize solely said second unit.

Claim 21

The bi-directional data transmission system as claimed in claim 19, wherein said bi-directional data transmission system is operative in a first, data transmission mode and in a second, data receive mode, said first generating means operative in said first mode for selecting ones of said clock pulses of said first signal to define said data transmission intervals and including modulating means operative in said second mode for modulating selected of said clock pulses of said first signal with data to be transmitted to and stored within said non-volatile memory.

Claim 22

The bi-directional data transmission system as claimed in claim 20, wherein said second generating means is operative in said first mode to respond to the clock pulses of said first signal appearing at said inductive coupling means for reading out said indication stored in said non-volatile means and for transmitting data indicative of said indication during said defined transmission intervals.

Claim 23

The bi-directional data transmission system as claimed in claim 21, wherein said second unit comprises demodulating means operative in said second mode for detecting and demodulating said selected modulated signals and for storing the demodulated data in said non-volatile memory means.

Claim 24

The bi-directional data transmission system as claimed in claim 1, wherein said first generating means generates a pair of first signals, each of said first signals being complimentary to the other of said first signals.

Claim 25

The bi-directional data transmission system as claimed in claim 23, wherein said first generating means generates each of said complimentary first signals as a train of regular clock pulses and transmission interval pulses, each transmission interval pulse defining the length of said transmission interval.

Claim 26

The bi-directional data transmission system as claimed in claim 24, wherein said inductive coupling means comprises a transformer having a primary winding coupled to said first unit and a secondary winding coupled to said second unit, said primary winding having first and second coils connected together at a tap, said first generating means applying its pair of complimentary first clock signals respectively across said first and second coils of said tapped primary winding.

Claim 27

The bi-directional data transmission system as claimed in claim 25, wherein said second unit comprises detection means coupled to said secondary winding for detecting and separating at least one of said complimentary first signals as transmitted from said primary winding to said secondary winding.

Claim 28

A bi-directional, digital data transmission system comprising: (a) a sole, saturable transformer having a primary winding coupled to an interrogation unit and a secondary winding coupled to a data gathering transponder unit, said transformer transmitting an interrogation signal in a first direction from said interrogation unit to said transponder unit and a data bearing response signal in a second direction from said transponder unit to said interrogation unit; (b) said interrogation unit comprising first means coupled to said primary winding for generating said interrogation signal, said interrogation signal comprised of a first train of regularly occurring digital clock pulses and transmission interval pulses, each transmission interval pulse defining a transmission interval for the transmission of said response signal, said transmission interval being of sufficient length to permit said transformer to desaturate to a level to permit efficient transmission of said response signal to said interrogation unit; and (c) said transponder unit comprising energy conversion means coupled to said secondary winding for providing the sole energization of said transponder unit in response to said transmitted clock signals of said interrogation signal appearing at said secondary winding, and second means responsive to said transmission interval pulses appearing at said secondary winding for generating and applying during said transmission intervals digital signals indicative of the gathered data to said secondary winding to be transmitted via said transformer to said interrogation unit.

Claim 29

A bi-directional, digital data transmission system comprising: (a) a sole, saturable transformer having a primary winding coupled to an interrogation unit and a secondary winding coupled to a data gathering transponder unit, said transformer transmitting an interrogation signal in a first direction from said interrogation unit to said transponder unit and a data bearing response signal in a second direction from said transponder unit to said interrogation unit; (b) said interrogation unit comprising first means coupled to said primary winding for generating said interrogation signal, said interrogation signal comprised of a first train of regularly occurring digital clock pulses and transmission interval pulses, each transmission interval pulse defining a transmission interval for the transmission of said response signal, said transmission interval being of sufficient length to permit said transformer to desaturate to a level to permit efficient transmission of said response signal to said interrogation unit; and (c) said transponder unit comprising energy conversion means coupled to said secondary winding for providing the sole energization of said transponder unit in response to said transmitted clock signals of said interrogation signal appearing at said secondary winding, and second means responsive to said transmission interval pulses appearing at said secondary winding for generating and applying during said transmission intervals digital signals indicative of the gathered data to said secondary winding to be transmitted via said transformer to said interrogation unit.

Claim 30

The bi-directional, digital data transmission system as claimed in claim 27, wherein said interrogation unit comprises means for setting the pulse width of selected of said clock pulses to form said transmission interval pulses.

Claim 31

The bi-directional, digital data transmission system as claimed in claim 28, wherein the pulse width of said transmission interval pulses is selected to be greater than the pulse width of said clock pulses to permit desaturation of said transformer to a level to permit efficient transmission of said second signal via said transformer to said interrogation unit.

Claim 32

The bi-directional, digital data transmission system as claimed in claim 27, wherein said transponder unit comprises detection means responsive to said interrogation signal appearing at said secondary winding for providing enable signals in response to the presence of said transmission interval pulses.

Claim 33

The bi-directional, digital data transmission system as claimed in claim 30, wherein said data transmitting means comprises a serial shift register for receiving and storing said digital signals indicative of the gathered data and responsive to each of said enable signals for shifting out a bit of said digital signals, and modulating means for modulating each bit of said gathered data signals and for applying said modulated data to said secondary winding to be transmitted via said transformer to said interrogator unit.

Claim 34

The bi-directional, digital data transmission system as claimed in claim 31, wherein said modulation means comprises an actuable source of a high frequency signal, the frequency of which is greater than that of said clock pulses of said interrogation signal, and means for selectively applying said high frequency signal to said secondary winding dependent upon whether said bit of said gathered data signal is a zero or a one.

Claim 35

The bi-directional, digital data transmission system as claimed in claim 27, wherein said first generating means generates a sequence of a given number of clock pulses followed by a single transmission interval pulse, said number of clock pulses being selected to ensure the sufficient energization of said transponder unit.

Claim 36

The bi-directional, digital data transmission system as claimed in claim 27, wherein said interrogation unit is portable and includes alignment means for aligning said primary winding with respect to said secondary winding of said transponder unit to ensure an inductive coupling therebetween.

Claim 37

The bi-directional, digital data transmission system as claimed in claim 31, wherein there is included meter means responsive to utility consumption for generating pulse-like, electrical signals, each indicative of the consumption of a given quantity of the utility, said detection means coupled.for receiving said pulse-like, electrical signal and responsive to said clock pulses of said interrogation signal for transferring an accumulated count of said pulse-like utility signals to said shift register.

Claim 38

The bi-directional, digital data transmission system as claimed in claim 35, wherein there is included non-volatile memory means for storing said count of said received pulse-like, electrical signals, said detection means for receiving and storing said pulse-like, electrical signals, in said non-volatile memory means, said detection means responsive to said interrogation signal for transferring said count from said non-volatile memory means to said shift register.