SPIKE MONITORING APPARATUS

• US 3,676,605 A
• Filed: 03/18/1969
• Issued: 07/11/1972
• Est. Priority Date: 03/18/1969
• Status: Expired due to Term

• Current Assignee: James W. Johnson
• Original Assignee: James W. Johnson
• Inventors: Johnson, James W.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US04/808,087
• Time in Patent Office: 1,211 Days
• Field of Search: 179/1MN,18.03,18.3A,18.3,89,16.2,5.5,6AC,6CO,18BE,18BD,16H
• US Class Current: 379/315
• CPC Class Codes: H04M 3/22 Arrangements for supervision, monitoring or testing
• CPC Class Codes: H04M 3/493 Interactive information services, e.g. directory enquiries ; Arrangements therefor, e.g. interactive voice response [IVR] systems or voice portals
• CPC Class Codes: H04Q 3/00 Selecting arrangements H04Q5/00 - H04Q11/00 take precedence

Abstract

Monitoring apparatus for an electrical circuit, as a telephone circuit, operable to discriminate between various signals and a particular signal different from any thereof and for utilizing the detection of the particular signal to perform a useful function. By way of example, the monitor is useful to discriminate between the various normal signals typically involved in the operation of telephone circuitry and the '"'"''"'"''"'"''"'"'on hook'"'"''"'"''"'"''"'"' and '"'"''"'"''"'"''"'"'off hook'"'"''"'"''"'"''"'"' signal inherently generated as an incident to reseating or removing the handpiece relative to its cradle. The resulting spike signal, even though of micro-second duration, is detected and utilized to trigger a circuit effective to disengage automatically central station equipment essential to the operation of the circuit and making it available for immediate use by other telephone subscribers. The monitoring apparatus, conventionally located with the equipment to be released, operates to arm itself automatically as an incident to the establishment of a telephone circuit and includes means for restoring the components to their initial condition automatically in response to opening an established telephone circuit at any terminal thereof.

Claims

1. That improvement in apparatus for monitoring a communication circuit between first and second stations and including switch gear operable to connect said first and second stations only when there is need for transmitting intelligence therebetween, said communication circuit being of the type coupled together by acoustical coil coupling means having a normally grounded center tap and including normally open first and second relay means having contacts in the communication circuit on either side of said coupling means, and said switch gear including means for processing ringing and the like service signals along said communication circuit, said improvement comprising:

means for monitoring said communication circuit so long as one of said first and second relays is activated for the appearance therein of a spike signal of micro-second duration occurring upon the release of said communication circuit at the associated end of said first or second stations and responsive to said spike signal to de-energize said one relay means, said monitoring means including fast action switch means, adjustable threshold means for distinguishing intelligence and service signals in this communication circuit from said micro-second spike signal and effective to bias said fast action switch means to its inactive open position for all intelligence and communication circuit service signals having a potential below a predetermined potential, diode means connected between the opposite Ends of said acoustical coil coupling means and said fast action switch means biased against response to said intelligence signals and said communication circuit service signals, and said fast action switch means being triggered in response to the appearance of said micro-second spike signal originating from either said first or said second station to deactivate any activated one of said first and second relays.

2. That improvement defined in claim 1 characterized in the provision of means for maintaining said relays deactivated for a minimum interval after restoring an active circuit between either of said first and second stations and effective to delay closing said relays during the transmission of ringing signals between the calling station and said central station.

3. That improvement defined in claim 1 characterized in that said means for deactivating any activated one of said first and second relays operates automatically and without human intervention following the appearance in said communication circuit of said spike signal thereby to release said central station equipment for use with another communication circuit.

4. That improvement defined in claim 1 characterized in the provision of circuit means operatively connected with said monitoring means and effective to restore said first and second relay means to the initial condition thereof automatically as an incident to the detection of a spike signal when either end of said communication circuit is opened at the end of a period of use.

5. That improvement defined in claim 1 characterized in that said means for distinguishing intelligence and service signals from said spike signals includes arming circuit means to detect said spike signal and including time delay means for rendering said arming circuit means effective in time delay sequence of adequate duration for completion of the ringing and service signals for the called station thereby to isolate said monitoring means from the latter signals during the ringing and answering period.

6. Telephone circuitry for controlling the use of telephone signal-operated switching equipment and for monitoring an operating telephone circuit via said switching equipment to detect a spike signal produced as an incident to releasing either station of the telephone circuit after a period of use, said circuitry having switching station means provided with at least one incoming and one outgoing line means adapted to be operatively connected to one another by acoustical coupling means, spike detector means comprising means including transistor means normally biased against conduction by the normal telephone operating signals, adjustable means for varying the normal bias effective to prevent conduction of said transistor means and operable to set the bias at a level rendering said transistor means immune to signals normally passing over said circuit but ineffective to interfere with the operation of said spike signal responsive means, means for utilizing a spike signal produced when releasing any station of a completed telephone circuit to counteract the normal bias on said transistor means and effective to trigger said transistor means, and means including circuit means responsive to the triggering of said transistor means to automatically disengage said switching equipment and restore the same to a standby condition.

7. Telephone circuitry as defined in claim 6 characterized in that said circuit means responsive to the triggering of said transistor means includes control relay means connected to one of said incoming and outgoing line means and having normally open contacts connected in circuit with said coupling means, said control means also including a normally open starting ground contact in circuit with time delay means for arming said spike detector means a predetermined period after said control relay means is energized, and means for energizing said control relay means in response to completion of a dial-controlled switching cycle.

8. Telephone cIrcuitry as defined in claim 7 characterized in the provision of means for restoring said time delay means to the initial condition thereof in readiness for the next timing cycle.