Patent EP0084400A2 successfully refreshed from Google Patents.
EP0084400A2
Expired / Lapsed
EP
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Detection system
Assignee: Nederlandsche Apparatenfabriek NEDAP NV
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Filing: 1983-01-14
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Granted: —
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Expires: 2003-01-14
Abstract
Abstract In an electronic detection system comprising a transmitter for generating an interrogation field, said transmitter being coupled with at least one transmitting antenna coil; a responder with a receiving coil and a transmitting coil for transmitting a signal in response to said interrogation field; and a receiver-and-detector coupled with at least one receiving antenna coil for receiving and further processing the signal transmitted by said responder, the improvement which consists in that said receiving coil and said transmitting coil of said responder are arranged in parallel to each other, and that said responder comprises a frequency divider connected between said receiving and transmitting coil and arranged to divide the signal frequency received by a factor N≧4.
Inventors
- 👤 Tallienco Wieand Harm Fockens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 22:10
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2414; G08B13/2428; G08B13/2431
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
118 words
In an electronic detection system comprising a transmitter for generating an interrogation field, said transmitter being coupled with at least one transmitting antenna coil; a responder with a receiving coil and a transmitting coil for transmitting a signal in response to said interrogation field; and a receiver-and-detector coupled with at least one receiving antenna coil for receiving and further processing the signal transmitted by said responder, the improvement which consists in that said receiving coil and said transmitting coil of said responder are arranged in parallel to each other, and that said responder comprises a frequency divider connected between said receiving and transmitting coil and arranged to divide the signal frequency received by a factor N Z 4.
Claim 2
Dependent Claim
118 words
In an electronic detection system comprising a transmitter for generating an interrogation field, said transmitter being coupled with at least one transmitting antenna coil; a responder with a receiving coil and a transmitting coil for transmitting a signal in response to said interrogation field; and a receiver-and-detector coupled with at least one receiving antenna coil for receiving and further processing the signal transmitted by said responder, the improvement which consists in that said receiving coil and said transmitting coil of said responder are arranged in parallel to each other, and that said responder comprises a frequency divider connected between said receiving and transmitting coil and arranged to divide the signal frequency received by a factor N Z 4.
Claim 3
Dependent Claim
28 words
A detection system according to claim 1, characterized in that the receiving coil and the transmitting coil of the responder are jointly arranged on a single ferrite rod.
Claim 4
Dependent Claim
16 words
A detection system according to claim 1 or 2, wherein the frequency divider is a divider-by-eight.
Claim 5
Dependent Claim
32 words
A detection system according to claim 1, 2 or 3, wherein the responder comprises a rectifying and smoothing circuit connected between the receiving coil and the supply terminals of the frequency divider.
Claim 6
Dependent Claim
106 words
A detection system as claimed in any of the preceding claims, wherein the transmitter comprises a high-frequency oscillator, which via at least one power amplifier energizes the transmitting antenna coil, as well as a modulation oscillator for frequency modulation of the signal from said high-frequency oscillator and for providing a reference signal to a synchronous detector of the receiver; and that the receiver-and-detector comprises a filtering device selectivity tuned to the frequency transmitted by the responder; an FM demodulator connected to said synchronous detector arranged to produce an output signal if the output signal of the FM demodulator is sufficiently in phase with said reference signal.
Claim 7
Dependent Claim
117 words
A detection system according to claim 5, wherein said synchronous detector comprises a synchronous switching device controlled by a reference signal and connected between a first terminal of an input to which the output signal of the FM demodulator is supplied and a parallel circuit comprising two branches, the first of which comprises a resistor and a diode, and the second of which comprises a resistor and a Zener diode, said parallel circuit being further connected to the negative input of an operational amplifier connected as anintegrator, the output of which operational amplifier forms the output of the synchronous detector, and the positive input of said operational amplifier being connected to the second terminal of said input.
Claim 8
Dependent Claim
48 words
A detection system according to claim 5 or 6, wherein the output of said Synchronous detector is connected to a level detector arranged to issue an energizing signal to an alarm or signalling device as soon as the output sognal of said synchronous detector reaches a set level.
Claim 9
Dependent Claim
17 words
A detection system according to claim 7, characterized in that said level detector is a monostable multivibrator.
Claim 10
Dependent Claim
104 words
A detection system according to any one of claims 1 - 4, characterized in that said transmitter comprises a high-frequency oscillator which via at least one power amplifier energizes the transmitting antenna coil, as well as a frequency divider connected to said high-frequency oscillator for dividing the high-frequency signal by the same factor N by which the frequency is divided in said responder, the output signal of the frequency divider being supplied to a phase separator having four outputs carrying signals differing 90 in phase relative to each other, which signals are supplied as reference signals to a synchronous detection device of the receiver-and-detector.
Claim 11
Dependent Claim
74 words
A detection system as claimed in claim 9, characterized in that the synchronous detection device comprises four synchronous detectors as claimed in claim 6, to each of which are supplied one of the output signals of said phase separator as well as the signal received by the receiving coil(s) of said responder, the outputs of said synchronous detectors being connected to an OR gate, the output of which is connected to a level detector.
Claim 12
Dependent Claim
23 words
A detection system as claimed in claim 10, characterized in that said level detector is a monostable multivibrator with an adjustable detection level.
Claim 13
Dependent Claim
41 words
A detection system as claimed in any one of the preceding claims, characterized in that the transmitting antenna coil(s) is (are) also the receiving antenna coil(s) with a separator being provided for the coupling with the transmitter and the receiver-and-detector, respectively.
Claim 14
Dependent Claim
117 words
A detection system as claimed in claim 12, characterized in that said separator together with said at least one transmitting/receiving antenna coil forms an antenna circuit, in which the transmitting/receiving antenna coil and a first capacitor form a first LC circuit capable of resonating to the transmission frequency, and that there is provided a second LC circuit cascade-connected to said first LC circuit, said second LC circuit being capable of resonating to the frequency transmitted by said responder and, in addition to a second coil and a second capacitor, comprising said at least one transmitting/receiving antenna coil, there being provided a third capacitor which together with said second foil forms a circuit resonating to the transmission frequency.
Claim 15
Dependent Claim
59 words
A detection system as claimed in claims 12 and 13, characterized by the formation of an antenna circuit symmetrical relative to ground by duplication of said second coil and said second and third capacitors, which antenna circuit is energized via a phase separator and two associated amplifiers by two signals differing 180 0 in phase relative to each other.
Claim 16
Dependent Claim
47 words
A detection system according to claim 12, 13 or 14, characterized by two transmitting/receiving antenna coils disposed substantially at right angles to each other, said coils being energized via associated antenna circuits with signals phase-shifted through 90 0 relatively to each other for generating a rotary field.
References Cited (Backward Citations)
No citation records indexed.
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