Line usage measuring circuit

Claim 2

A circuit for determining usage of a telephone line by ascertaining station call attempts and call completions routed through a telephone central office comprising means for detecting station generated off-hook signals and registering ones of the off-hook signals as outgoing call attempts, means enabled by said detecting and registering means for recording answer signals generated by the telephone central office as outgoing call completions, and means for recording telephone central office generated ringing signals as incoming call attempts and enabling said detecting and registering means to record ones of the station generated off-hook signals occurring within a predetermined time interval as incoming call completions.

Claim 3

The circuit set forth in claim 1 wherein said detecting and registering means comprises a first relay, and means bridged across the telephone line and enabled by the station generated off-hook signals for operating said first relay in response to initial ones of the station off-hook signals.

Claim 4

The circuit set forth in claim 2 wherein said recording means comprises a second relay, and means coupled to the telephone line and enabled by the telephone central office answer signals for activating said second relay in response thereto.

Claim 5

The circuit set forth in claim 3 wherein said recording and enabling means comprises a third relay, timing means for defining the predetermined time interval and for establishing a holding path for said third relay during the time interval, bridge means coupled to the telephone line through break contacts of said first relay for generating enabling signals in response to the central office ringing signals, means enabled by a first one of said enabling signals for enabling operation of said third relay, means enabled by each of said enabling signals for directing said timing means to initiate the predetermined time interval, and means enabled by each of said enabling signals for inhibiting said operating means from operating in response to the ringing signals.

Claim 6

The circuit set forth in claim 4 further including means including make and break contacts of said first, second, and third relays for generating signals identifying the incoming and outgoing call attempts and call completions.

Claim 7

A circuit for determining station usage of a multiconductor telephone line by ascertaining incoming and outgoing call attempts and call completions for a station connected by the telephone line to a telephone central office comprising means bridged across a first two of the conductors for detecting station generated off-hook signals and registering ones of the off-hook signals as outgoing call attempts, means coupled to the telephone line and enabled by said detecting and registering means for recording answer signals generated by the telephone central office as outgoing call completions, and means coupled to the first two conductors by said detecting and registering means for recording central office generated ringing signals as incoming call attempts and for enabling said detecting and registering means to subsequently record ones of the station generated off-hook signals occurring within a predetermined time interval as incoming call completions.

Claim 8

A circuit for determining station usage of a multiconductor telephone line by ascertaining incoming and outgoing call attempts and call completions for a station connected by the telephone line to a telephone central office comprising means bridged across a first two of the conductors for detecting station generated off-hook signals and registering ones of the off-hook signals as outgoing call attempts, means coupled to the telephone line and enabled by said detecting and registering means for recording answer signals generated by the telephone central office as outgoing call completions, and means coupled to the first two conductors by said detecting and registering means for recording central office generated ringing signals as incoming call attempts and for enabling said detecting and registering means to subsequently record ones of the station generated off-hook signals occurring within a predetermined time interval as incoming call completions.

Claim 9

The circuit set forth in claim 6 wherein said detecting and registering means comprises a first relay, a first transistor having its collector-to-emitter path serially inserted in the operate path of said first relay, a plurality of transistors having their base paths connected to ones of the first two conductors and their collector-to-emitter paths serially connected between Ground and a battery source, and a pair of transistors enabled by current flowing through the collector-to-emitter paths of said plurality of transistors for forward-biasing said first transistor to operate said first relay.

Claim 10

The circuit set forth in claim 7 wherein said recording means comprises a second relay, first circuit apparatus connected through first make contacts of said first relay across the first two conductors for operating said second relay in response to ones of the answer signals appearing on the first two conductors, second circuit apparatus connectable to a third one of the conductors for operating said second relay in response to ones of the answer signals applied to the third conductor, and means including first make contacts of said second relay in combination with second make contacts of said first relay for holding said second relay operated under control of said first relay.

Claim 11

The circuit set forth in claim 8 wherein said recording and registering means comprises a third relay, timing circuit apparatus enabled by operation of said third relay for defining the predetermined time interval and for establishing a holding path for said third relay during the predetermined time interval, bridge circuit apparatus coupled across the first two conductors through series first break contacts of said first and said second relays for generating enabling signals in response to the central office ringing signals, a second transistor connected to said bridge circuit and connectable to one of the first two conductors for operating said third relay in response to a first one of the enabling signals and a first one of the central office ringing signals, a third transistor connected to said bridge circuit and enabled by each of the enabling signals for directing said timing circuit apparatus to initiate the predetermined time interval, and a fourth transistor connected to said bridge circuit and enabled by each of the enabling signals for reverse-biasing and first transistor to its nonconducting state during occurrence of the ringing signals.

Claim 12

The circuit set forth in claim 9 further including third circuit apparatus connectable to the one first conductor for inhibiting said first circuit apparatus from operating in response to premature ones of the answer signals appearing on the first two conductors.

Claim 13

The circuit set forth in claim 9 further including a first output lead for indicating the outgoing call attempts including third make contacts of said first relay in series combination with second break contacts of said second relay and first break contacts of said third relay. a second output lead for indicating the outgoing call completions including fourth make contacts of said first relay in series combination with second make contacts of said second relay, a third output lead for indicating the incoming call attempts including first make contacts of said third relay in series combination with said second break contacts of said second relay, and a fourth output lead for indicating the incoming call completions including second make contacts of said third relay in series combination with said second make contacts of said second relay.

Claim 14

A line usage measuring circuit for determining station usage of a multiconductor telephone line by ascertaining incoming and outgoing call attempts and call completions for loop and ground start telephone stations connected by the telephone line to a telephone central office comprising a plurality of relays each having make contacts and break contacts, first transistor means bridged across a first two of the telephone line conductors for detecting station generated off-hook signals and operating a first one of said relays in response to ones of the off-hook signals, second transistor means connected across the two conductors through first make contacts of said first relay and first break contacts of a second one of sAid relays for operating said second relay in response to telephone central office generated answer signals appearing on the two conductors, first conduit means connectable to a third one of the telephone line conductors for operating said second relay in response to ones of the answer signals appearing on the third conductor, timing means enabled by the operation of a third one of said relays for establishing a holding path for said third relay for a predetermined interval of time, bridging means bridged across the two conductors through first break contacts of said first relay and said first break contacts of said second relay for generating enabling signals in response to telephone central office generated ringing signals appearing on the two conductors, a first transistor connected to said bridging means and connectable to one of the two conductors for operating said third relay in response to a first one of the enabling signals and one of the ringing signals appearing on the one conductor, a second transistor connected to said bridging means and enabled by each one of the enabling signals for inhibiting said first transistor means from operating said second relay during occurrence of the ringing signals, a third transistor connected to said bridging means and enabled by each one of the enabling signals for directing said timing means to initiate the predetermined interval of time, means including first make contacts of said third relay for enabling said first transistor means to operate said second relay in response to ones of the off-hook signals occurring within the predetermined interval of time, and means enabled by operation of said first, second, and third relays for generating signals identifying the incoming and outgoing call attempts and call completions for the loop and ground start telephone stations.

Claim 15

A line usage measuring circuit for determining station usage of a multiconductor telephone line by ascertaining incoming and outgoing call attempts and call completions for loop and ground start telephone stations connected by the telephone line to a telephone central office comprising a plurality of relays each having make contacts and break contacts, first transistor means bridged across a first two of the telephone line conductors for detecting station generated off-hook signals and operating a first one of said relays in response to ones of the off-hook signals, second transistor means connected across the two conductors through first make contacts of said first relay and first break contacts of a second one of sAid relays for operating said second relay in response to telephone central office generated answer signals appearing on the two conductors, first conduit means connectable to a third one of the telephone line conductors for operating said second relay in response to ones of the answer signals appearing on the third conductor, timing means enabled by the operation of a third one of said relays for establishing a holding path for said third relay for a predetermined interval of time, bridging means bridged across the two conductors through first break contacts of said first relay and said first break contacts of said second relay for generating enabling signals in response to telephone central office generated ringing signals appearing on the two conductors, a first transistor connected to said bridging means and connectable to one of the two conductors for operating said third relay in response to a first one of the enabling signals and one of the ringing signals appearing on the one conductor, a second transistor connected to said bridging means and enabled by each one of the enabling signals for inhibiting said first transistor means from operating said second relay during occurrence of the ringing signals, a third transistor connected to said bridging means and enabled by each one of the enabling signals for directing said timing means to initiate the predetermined interval of time, means including first make contacts of said third relay for enabling said first transistor means to operate said second relay in response to ones of the off-hook signals occurring within the predetermined interval of time, and means enabled by operation of said first, second, and third relays for generating signals identifying the incoming and outgoing call attempts and call completions for the loop and ground start telephone stations.

Claim 16

A line usage measuring circuit having a three conductor input connectable to telephone line conductors normally having a negative potential appearing on a first line conductor and a ground potential appearing on a second line conductor and arranged for ascertaining incoming and outgoing call attempts and call completions for a telephone station coupled to the telephone line conductors comprising means connected to a first two of the input conductors for detecting decreases in the voltage potential normally appearing across the first and second telephone line conductors and registering ones of the decreases of voltage potential as outgoing call attempts, means coupled to the first two input conductors and enabled by said detecting and registering means for recording reversals of the voltage potential normally appearing across the first and second telephone line conductors as outgoing call completions, means coupled to the first two input conductors by said detecting and registering means for detecting ringing signals appearing on the first and second telephone line conductors and recording the ringing signals as incoming call attempts, and means for enabling said detecting and registering means to record ones of the decreases of voltage potential occurring within a predetermined interval of time following the ringing signals as incoming call completions.

Claim 17

A line usage measuring circuit having a three conductor input connectable to telephone line conductors normally having a negative potential appearing on a first line conductor and a ground potential appearing on a second line conductor and arranged for ascertaining incoming and outgoing call attempts and call completions for a telephone station coupled to the telephone line conductors comprising means connected to a first two of the input conductors for detecting decreases in the voltage potential normally appearing across the first and second telephone line conductors and registering ones of the decreases of voltage potential as outgoing call attempts, means coupled to the first two input conductors and enabled by said detecting and registering means for recording reversals of the voltage potential normally appearing across the first and second telephone line conductors as outgoing call completions, means coupled to the first two input conductors by said detecting and registering means for detecting ringing signals appearing on the first and second telephone line conductors and recording the ringing signals as incoming call attempts, and means for enabling said detecting and registering means to record ones of the decreases of voltage potential occurring within a predetermined interval of time following the ringing signals as incoming call completions.

Claim 18

The line usage measuring circuit set forth in claim 13 further including means connected to a third one of the input conductors for registering an answer voltage potential appearing on a third one of the telephone line conductors as an outgoing call completion, and means connected to one of the first two input conductors for inhibiting said recording means from operating in response to premature ones of the voltage potential reversals appearing across the first and second telephone line conductors.