SWEEP SIGNAL METER READING SYSTEM

• US 3,719,928 A
• Filed: 02/10/1971
• Issued: 03/06/1973
• Est. Priority Date: 04/03/1970
• Status: Expired due to Term

• Current Assignee: Fumio Aoki, Hideo Kobayashi, Hiroshi Oishi, Shigeru Kawanno, Takeo Hyodo, Yasushi Kudo
• Original Assignee: Fumio Aoki, Hideo Kobayashi, Hiroshi Oishi, Shigeru Kawanno, Takeo Hyodo, Yasushi Kudo
• Inventors: Oishi, Hiroshi, Aoki, Fumio, Kawanno, Shigeru, Kudo, Yasushi, Kobayashi, Hideo, Hyodo, Takeo
• Primary Examiner(s): Pitts, Harold
• Application Number:
  US05/114,211
• Time in Patent Office: 755 Days
• Field of Search: 340/151R 179/2A
• US Class Current: 340/870.03
• CPC Class Codes: H04Q 9/08 Calling by using continuous ac

Abstract

An information detection method and system for carrying out the automatic reading of meters disposed in domestic users houses. A series resonance circuit having a peculiar resonance frequency is connected in parallel to each meter and on-off controlled by the meter at certain quantity of consumption. A sweep oscillator generates a sweep signal and supplied it through hybrid circuits to the resonance circuit, the hybrid circuits mixing the sweep signal and the reflected signal to provide a detection signal with no noise. Such a detection signal is allowed to pass through a gate which is controlled by the sweep signal and reference resonance circuits.

Claims

1. An information detection system for detecting the data of a multiplicity of information sources coupled to a line, utilizing a sweep generator and the switching of resonance circuits associated individually with the respective information sources, comprising:

first hybrid circuit means for connecting the output of a sweep generator to said line through a first terminal and for deriving the reflected wave from said line through a second terminal, limiting means connected to said sEcond terminal for amplitude limiting said reflected wave, and means for mixing the reflected wave with the output of said sweep generator after amplitude limitation to generate a detection output;

second hybrid circuit means connected to said sweep generator for preventing noises and the reflected waves from said line from mixing into said output of the sweep generator; and

third hybrid circuit means for applying a part of the output of said sweep generator to a parallel connection circuit of series resonance impedances which resonate at respective sampling frequencies, means for mixing the reflected wave with said output of the sweep generator to provide a sampling pulse, and means for sampling the detection output in response to generation of said sampling pulse.

2. A system for detecting data in a multiplicity of information sources coupled to a line by opening and closing resonance circuits individually associated with the respective information sources, comprising:

a. a sweep generator generating an output signal including a plurality of frequencies;

b. at least one hybrid circuit means for transmitting the output signal of said sweep generator to said line through inputs and outputs thereof, one part of said hybrid circuit means having a further output for delivering a reflected signal from said line and the other part of said hybrid circuit means having a further output for delivering the output signal of said sweep generator;

c. at least one amplitude limiter for limiting the amplitude of the reflected signal which is received from the further output of the one part of said hybrid circuit means so as to deliver an amplitude-limited output signal;

d. at least one ring modulator receiving the output signal of said amplitude limiter and the output signal delivered by the further output of the other part of said hybrid circuit means and mixing said signals so as to form therefrom a first phase dependent output signal;

e. at least one terminal circuit comprising a parallel connection of series resonant impedances;

f. at least a second hybrid circuit means for transmitting a part of the output signal of said sweep generator to said terminal circuit through inputs and outputs thereof, one portion of said second hybrid circuit means having a further output for delivering a standard reflected signal which is received from said terminal circuit and the other portion of said second hybrid circuit means having a further output for delivering the output signal of said sweep generator;

g. at least one second ring modulator for receiving the standard reflected output signal and the further output signal and mixing said signals so as to form therefrom a second phase dependent output signal and delivering the same; and

h. at least one gate (161) controlled by the second phase dependent output signal to gate the first phase dependent output signal.

3. A system according to claim 2, characterized in that the circuit components (b) to (h) are combined to form at least one scanning unit.

4. A system according to claim 3, characterized in that said at least one scanning unit is associated with said sweep generator.