SIGNAL TRANSMISSION LINE FOR AUTOMATIC GAUGE INSPECTION SYSTEM

• US 3,820,106 A
• Filed: 05/17/1971
• Issued: 06/25/1974
• Est. Priority Date: 05/20/1970
• Status: Expired due to Term

• Current Assignee: Hiroshi Yamashita, Michihiro Ishizaka
• Original Assignee: Hiroshi Yamashita, Michihiro Ishizaka
• Inventors: Yamashita, Hiroshi, Ishizaka, Michihiro
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/144,163
• Time in Patent Office: 1,135 Days
• Field of Search: 340/310,151 175/17R,7A
• US Class Current: 340/870.07
• CPC Class Codes: H02J 13/00009 using pulsed signals
• CPC Class Codes: H04Q 9/10 using single different frequencies
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

Metering devices such as utility meters include series resonant circuits connected in parallel to a common transmission line through indicating means comprising normally open contacts. Each time the meter integrates one unit of power, its contacts are closed for a predetermined time. A sampling means in a repeater successively delivers to the line different frequencies assigned to each of the circuits. If one of the resonant circuits receives its own frequency during the closure of its contacts, a decrease in line impedance is sensed by the repeater and its associated memory means such as a register counts '"'"''"'"''"'"''"'"'ONE'"'"''"'"''"'"''"'"'. The transmission line includes a neutral conductor of a three-phase three-wire distribution system and a covered signal transmission conductor juxtaposed in an electrically insulated relationship by an insulation.

Claims

1. In combination:

a power distribution system supplying power during use and including a neutral conductor; and

an automatic meter reading system comprising, a plurality of metering devices recording incrementally a measurable physical quantity, each metering device having indicating means receptive of sampling signals applied thereto for indicating information having a content corresponding to the incremental variations of said physical quantity, sampling means for developing sampling signals and for sampling the information of each metering device individually, said sampling means having memory means for storing said information of each metering device, means defining a sampling signal transmission circuit isolated from the supplied power comprising said neutral conductor and a signal transmission conductor extending longitudinally in a side-by-side relationship with said neutral conductor both connecting each of said metering devices to said sampling means and means insulating said conductors including insulation insulating them electrically from each other, whereby said neutral conductor simultaneously serves as a power conductor and a signal conductor.

2. The combination according to claim 1, wherein said means insulating joins said neutral conductor and said signal transmission conductor in a unitary structure.

3. The combination according to claim 1, wherein said signal transmission conductor is a stranded conductor.

4. The combination according to claim 1, including another signal transmission conductor juxtaposed in an electrically insulated relationship with said neutral conductor, whereby the signal transmission conductors define a plurality of independent signal transmission lines.

5. The combination according to claim 1, wherein said metering devices are electric power meters each comprising a tuned circuit having a predetermined iNdividual frequency, different from the frequency of the other metering devices, said sampling means having means to generate said sampling signal at different frequencies corresponding to the individual frequencies of the metering devices.