Telephone test instrument - Patent Review 5025466

Claims

What is claimed is:

1. A telephone test instrument, comprising: a housing adapted to be hand-held by a telephone technician;

a receiver disposed in said housing;

a transmitter disposed in said housing;

circuit means, disposed in said housing and within which said receiver and transmitter are connected, for establishing communication with a telephone circuit, said circuit means including a microprocessor; and

data entry means for entering data to said microprocessor, said data entry means including a plurality of dual-function keys mounted on said housing and connected so that actuation of said keys is detected by said microprocessor, and said data entry means also including indicia means integrated with said keys and said housing for labeling said keys with the dual functions each of said keys is adapted for selecting.

2. An instrument as defined in claim 1, further comprising data output means, mounted on said housing, for visually outputting data from said microprocessor to the telephone technician without an alphabetical or numerical display.

3. An instrument as defined in claim 1, wherein:

said circuit means further includes: a dial pulse signaling circuit; and a tone signaling circuit; and

said microprocessor is connected to said dial pulse signaling circuit and said tone signaling circuit for alternatively controlling the operation thereof so that, for said dial pulse signaling circuit, the speed of transmitting pulses through said dial pulse signaling circuit and the break between said pulses are variable and further so that, for said tone signaling circuit, the generation of one or two tones and the frequency thereof are variable.

4. An instrument as defined in claim 1, further comprising means for connecting said circuit means to receive energization from the telephone circuit.

5. An instrument as defined in claim 1, wherein:

said instrument further comprises an energy supply; and

said circuit means further includes means, responsive to said microprocessor, for connecting said circuit means to receive energization from said energy supply.

6. An instrument as defined in claim 5, further comprising means for connecting said circuit means to receive energization from the telephone circuit.

7. An instrument as defined in claim 6, wherein said means for connecting said circuit means to receive energization from the telephone circuit and said means for connecting said circuit means to receive energization from said energy supply cooperatively operate to energize said circuit means first from the telephone circuit up to a predetermined maximum current and thereafter from said energy supply.

8. An instrument as defined in claim 5, wherein:

said energy supply is rechargeable; and

said circuit means further includes means, responsive to said microprocessor, for providing a recharging current to said rechargeable energy supply from the telephone circuit.

9. An instrument as defined in claim 1, wherein said circuit means further includes means for communicating a signal representative of loop current to said microprocessor for measurement thereby while said circuit means and said receiver and transmitter are connected to the telephone circuit.

10. An instrument as defined in claim 9, wherein said circuit means further includes means, responsive to said microprocessor, for signaling the loop current measurement to the telephone technician without an alphabetical or numerical display.

11. An instrument as defined in claim 1, wherein:

said instrument further comprises a loudspeaker disposed in said housing; and

said circuit means further includes:

means, connected to said loudspeaker and responsive to said microprocessor, for actuating said loudspeaker at a selected volume level; and

means, responsive to said microprocessor, for connecting said receiver to said means for actuating said loudspeaker at a selected volume level.

12. An instrument as defined in claim 1, wherein said circuit means further includes memory means, connected to said microprocessor, for storing a plurality of 27-digit numbers entered into said microprocessor.

13. An instrument as defined in claim 1, wherein said circuit means further includes:

first hold current circuit means, responsive to said microprocessor, for selectably passing a current to hold the telephone circuit; and

second hold current circuit means, responsive to said microprocessor, for selectably passing, mutually exclusively of said first hold current circuit, a current to hold the telephone circuit.

14. A telephone test instrument, comprising:

a portable housing;

a receiver disposed in said housing;

a transmitter disposed in said housing;

a loudspeaker disposed in said housing; means for connecting said instrument to a telephone circuit;

a hold circuit disposed in said housing and connected to said means for connecting;

a hybrid circuit disposed in said housing and connected to said transmitter;

first switch means, disposed on said housing, for selectably connecting said hybrid circuit to either said hold circuit or said means for connecting;

a monitor circuit disposed in said housing and connected to said means for connecting;

a selectably energizable amplifier disposed in said housing and connected to said loudspeaker;

second switch means, disposed on said housing, for selectably connecting said amplifier to either said hybrid circuit or said monitor circuit;

third switch means, disposed in said housing, for selectably connecting said receiver to either said second switch means or said amplifier;

fourth switch means, disposed in said housing, for energizing said amplifier and operating said third switch means;

a programmed data processor disposed in said housing, said processor including means for operating said fourth switch means;

an energy supply disposed in said housing;

a recharging circuit disposed in said housing and connected to said means for connecting, said hold circuit, said energy supply and said processor;

means, disposed in said housing and connected to said hold circuit, for selectably communicating a telephone number by pulse or by tone in response to said processor;

a loop current detection circuit disposed in said housing and connected to said means for connecting and said processor; and

data entry means, disposed on said housing and connected to said processor, for entering data, including commands, into said processor.

15. A telephone test instrument, comprising:

a portable housing adapted to be hand-held by a telephone technician;

means, disposed in said housing, for making voice frequency transmissions and operational tests of trunk circuits and subscriber lines in a telephone network,

work, said means including:

means for connecting said test instrument to a telephone circuit;

a rechargeable battery; and

means, connected to said means for connecting and to said rechargeable battery, for recharging said battery from the telephone circuit.

16. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a rechargeable energy supply;

means, connected to said means for connecting and to said rechargeable energy supply, for recharging said energy supply from the telephone circuit;

means, connected to said means for connecting, for energizing said instrument from the telephone circuit with a current up to a predetermined current load; and

means, connected to said energy supply, for connecting said energy supply to energize said instrument with additional current in response to said instrument requiring current above the predetermined current

17. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a rechargeable energy supply; and

means, connected to said means for connecting and to said rechargeable energy supply, for recharging said energy supply from the telephone circuit, wherein said means for recharging includes:

means for determining loop current drawn through said instrument;

means for selectably conducting a recharging current to said energy supply from the telephone circuit; and

means for operating said means for selectably conducting in response to said means for determining loop current.

18. An instrument as defined in claim 17, wherein said means for operating includes:

means for preventing said means for selectably conducting from conducting a recharging current in response to said means for determining determining the loop current has fallen below a first predetermined magnitude; and

means for enabling said means for selectably conducting to conduct a recharging current in response to said means for determining determining the loop current has risen above a second predetermined magnitude.

19. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a rechargeable battery;

means, connected to said means for connecting and to said rechargeable battery, for recharging said battery from the telephone circuit;

means for measuring a voltage produced by said battery; and

means, responsive to said means for measuring, for signaling the magnitude of the voltage measurement without an alphabetical or numerical display.

20. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a rechargeable energy supply;

means, connected to said means for connecting and to said rechargeable energy supply, for recharging said energy supply from the telephone circuit;

a voice communication circuit operable in either a monitor mode or a talk mode;

voice communication circuit switch means for selectably connecting said voice communication circuit to said means for connecting in either the monitor mode or the talk mode;

energy supply switch means for selectably connecting said energy supply to provide energy to said instrument; and

a data processor connected to said voice communication circuit switch means and said energy supply switch means and programmed for operating said energy supply switch means to connect said energy supply to provide energy to said instrument in response to said voice communication circuit switch means connecting said voice communication circuit to said means for connecting in the talk mode.

21. An instrument as defined in claim 20, further comprising means for actuating said data processor to operate said energy supply switch means to connect said energy supply to provide energy to said instrument when said voice communication circuit switch means connects said voice communication circuit to said means for connecting in the monitor mode.

22. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a rechargeable energy supply;

means, connected to said means for connecting and to said rechargeable energy supply, for recharging said energy supply from the telephone circuit;

a primary hold circuit connected to said means for connecting; and

wherein said means for recharging includes:

a secondary hold circuit connected to said means for connecting;

a recharging circuit connected to said secondary hold circuit and said energy supply; and

a data processor programmed for activating said secondary hold circuit and said recharging circuit and for concurrently deactivating said primary hold circuit when said energy supply is to receive a recharging current.

23. A telephone test instrument, comprising: means for connecting said test instrument to a telephone circuit;

an internal energy supply;

means, connected to said means for connecting, for energizing said instrument from the telephone circuit with a current up to a predetermined current load; and

means, connected to said energy supply, for connecting said energy supply to energize said instrument with additional current in response to said instrument requiring current above the predetermined current load.

24. A telephone test instrument, comprising:

a portable housing adapted to be hand-held by a telephone technician:

means, disposed in said housing, for making voice frequency transmissions and operational tests of trunk circuits and subscriber lines in a telephone network, said means including:

means for connecting said test instrument to a telephone circuit;

an internal battery;

means for measuring a voltage produced by said battery; and

light-emitting means, responsive to said means for measuring, for signaling the voltage measurement without an alphabetical or numerical display.

25. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

an internal energy supply;

a voice communication circuit operable in either a monitor mode or a talk mode;

voice communication circuit switch means for selectably connecting said voice communication circuit to said means for connecting in either the monitor mode or the talk mode;

energy supply switch means for selectably connecting said energy supply to provide energy to said instrument; and

a data processor connected to said voice communication circuit switch means and said energy supply switch means and programmed for operating said energy supply switch means to connect said energy supply to provide energy to said instrument in response to said voice communication circuit switch means connecting said voice communication circuit to said means for connecting in the talk mode.

26. An instrument as defined in claim 25, further comprising means for activating said data processor to operate said energy supply switch means to connect said energy supply to provide energy to said instrument when said voice communication circuit switch means connects said voice communication circuit to said means for connecting in the monitor mode.

27. A method of testing a telephone circuit, comprising:

connecting a telephone test instrument to a telephone circuit, which test instrument includes a voice communication circuit and a test circuit;

energizing at least the test circuit with energy from the telephone circuit; and

testing the telephone circuit with the test circuit energized from the telephone circuit.

28. A method as defined in claim 27, further comprising:

additionally energizing at least the test circuit with energy from a rechargeable energy supply within the test instrument; and

selectively recharging the energy supply with a recharging current from the telephone circuit.

29. A method as defined in claim 28, further comprising:

measuring a voltage produced from the energy supply; and

serially flashing a light to correspond to the numerical value of the measured voltage.

30. A method as defined in claim 28, wherein said step of selectively recharging the energy supply includes:

preventing flow of a recharging current from the telephone circuit in response to a loop current flowing through the telephone circuit and test instrument decreasing below a first predetermined magnitude; and

enabling flow of a recharging current from the telephone circuit in response to the loop current increasing above a second predetermined magnitude.

31. A method as defined in claim 28, wherein said step of selectively recharging the energy supply includes periodically determining with a programmed data processor within the test instrument whether to recharge the energy supply.

32. A telephone test instrument, comprising:

a receiver;

a transmitter;

means for connecting said receiver and said transmitter to a telephone circuit; and

means for measuring loop current through said test instrument, said means for measuring connected to said means for connecting so that loop current is measured while said receiver and transmitter are connected to the telephone circuit.

33. An instrument as defined in claim 32, further comprising means, responsive to said means for measuring loop current, for signaling a loop current measurement without an alphabetical or numerical display.

34. An instrument as defined in claim 32, wherein said means for measuring loop current includes:

a resistor connected to said means for connecting so that loop current flows through said resistor;

means, connected to said resistor, for providing a sensing voltage in response to the magnitude of loop current flowing through said resistor; and

means for computing the magnitude of the loop current in response to the sensing voltage.

35. An instrument as defined in claim 34, wherein said means for computing includes:

an analog-to-digital converter connected to said means for providing a sensing voltage; and

a programmed data processor connected to said analog-to-digital converter.

36. An instrument as defined in claim 35, further comprising two light emitting diodes operated by said programmed data processor to signal the magnitude of a loop current measurement.

37. An instrument as defined in claim 35, wherein said means for providing a sensing voltage includes a Zener diode having an anode connected to said resistor and having a cathode connected to said analog-to-digital converter.

38. A telephone test instrument, comprising:

a housing;

an electrically conductive hook connected to said housing;

means, retained by said housing, for connecting said instrument to a telephone circuit; and

a switch mounted on said housing, said switch including two terminals, one of said terminals connected to said hook and the other of said terminals connected to said means for connecting so that the telephone circuit is electrically grounded in response to touching said hook to an electrical ground and closing said switch.

39. A telephone test instrument operable in either a loudspeaker-on mode or a loudspeaker-off mode, comprising:

a housing;

a receiver disposed in said housing;

a loudspeaker disposed in said housing;

means for operating said receiver at a base level in response to a signal received by said test instrument over a telephone circuit during the

means for operating said loudspeaker in response to a signal received by said test instrument over the telephone circuit during the loudspeaker-on mode; and

means for operating said receiver at a level not less than the base level during the loudspeaker-on mode.

40. An instrument as defined in claim 39, wherein:

said means for operating said loudspeaker includes amplifier means, connected to said loudspeaker, for providing an output signal to which said loudspeaker is responsive; and

said means for operating said receiver at a level not less than the base level includes means for connecting said receiver to said amplifier means so that said receiver is responsive to said output signal of said amplifier means during the loudspeaker-on mode.

41. A telephone test instrument, comprising:

means for connecting said test instrument to a telephone circuit;

a voice communication circuit connected to said means for connecting, said voice communication circuit including a receiver and a transmitter;

a loudspeaker;

amplifier means, connected to said voice communication circuit and said loudspeaker, for driving said loudspeaker;

first switch means for selectably connecting said receiver so that said receiver is driven either directly by said voice communication circuit or by said amplifier means; and

second switch means for selectably energizing said amplifier means and operating said first switch means so that said receiver is driven by said amplifier means when said amplifier means is energized.

42. An instrument as defined in claim 41, further comprising third switch means, responsive to said second switch means, for connecting a resistor across said transmitter when said amplifier means is energized.

43. A telephone test instrument, comprising:

a receiver;

a transmitter;

circuit means for connecting said receiver and transmitter to tip and ring lines of a telephone circuit so that loop current of the telephone circuit flows through said instrument, said circuit means including:

a positive temperature coefficient resettable fuse;

a triac connected to said fuse so that said fuse and said triac are connected in series across the tip and ring lines of the telephone circuit in response to connection of said instrument to the tip and ring lines; and

means, connected to said triac, for activating said triac to be conductive in response to a predetermined magnitude of loop current flowing through said instrument so that the loop current flows through said series connected fuse and triac.

44. An instrument as defined in claim 43, wherein:

said circuit means further includes an instrument operating circuit connected in parallel to said triac, said operating circuit including a resistor through which the loop current flows during selected operation of said operating circuit; and

said means for activating said triac includes an opto-coupled triac connected to said resistor and to said triac connected in series with said fuse.

BACKGROUND OF THE INVENTION

This invention relates generally to a telephone test instrument and more particularly, but not by way of limitation, to a telephone technician's hand-set used in testing subscriber loops of a telephone network.

A conventional telephone instrument through which telephone calls are made is referred to as a telephone subscriber set. A subscriber set at a home or business, for example, is connected to a local switching center of the telephone network through wires which extend between the location of the subscriber set and the location of the local switching center. The two wires to which the subscriber set connects are designated tip and ring lines, and the circuit defined from the local switching center to the subscriber set through the two wires is referred to as a subscriber loop.

When the subscriber who has the set reports a problem with the telephone circuit, a telephone technician can go to locations along the subscriber loop and connect a portable telephone test instrument, sometimes called a butt-set, across the two wires. Such a test instrument of the type to which we are referring has at least the capability of transmitting voice signals onto and receiving voice signals from the connected loop. typically such an instrument can selectably monitor or seize the circuit, dial into a seized circuit and conduct voice communications. Specific types of such test instruments have various other capabilities. Although such various test instruments exist, there is the need for an improved instrument having other and improved features.

SUMMARY OF THE INVENTION

The present invention meets the aforementioned need by providing a novel and improved telephone test instrument. The present invention is controlled by a programmed data processor. This permits operations of the instrument to be varied by software changes rather than hardware changes. The present invention uses energy from the telephone circuit, but it also has a rechargeable internal energy supply which provides energy above the level taken from the telephone circuit. The rechargeable energy supply recharges off energy from the telephone circuit. The present invention also has the capability of testing loop current flowing in the subscriber loop without having to disconnect a voice communication circuit of the instrument from the subscriber loop. The present invention also can perform a ground start on the subscriber loop using an external belt hook of the instrument so that an additional connector lead is not needed. An instrument of the present invention also includes a loudspeaker in addition to a receiver and transmitter of the voice communication circuit. During operation of the loudspeaker, the receiver remains active. The loudspeaker is automatically turned off or prevented from being turned on if the voltage of the internal energy supply, which is automatically continually (periodically) checked by the data processor, is too low. An instrument of the present invention includes an overcurrent protection circuit using a positive temperature coefficient resettable fuse and a triac across which the instrument operating circuit of the instrument is connected in parallel. Any particular instrument constructed in accordance with the present invention need not include all of the aforementioned features as indicated by the following combinations defining the present invention.

The present invention provides a telephone test instrument, comprising: a housing adapted to be hand-held by a telephone technician; a receiver disposed in the housing; a transmitter disposed in the housing; and circuit means, disposed in the housing and within which the receiver and transmitter are connected, for establishing communication with a telephone circuit, the circuit means including a microprocessor.

The present invention provides a telephone test instrument, comprising means for connecting the test instrument to a telephone circuit; a rechargeable energy supply; and means, connected to the means for connecting and to the rechargeable energy supply, for recharging the energy supply from the telephone circuit.

The present invention provides a telephone test instrument, comprising: means for connecting the test instrument to a telephone circuit; an internal energy supply; means, connected to the means for connecting, for energizing the instrument from the telephone circuit with a current up to a predetermined current load; and means, connected to the energy supply, for connecting the energy supply to energize the instrument with additional current in response to the instrument requiring current above the predetermined current load.

The present invention provides a telephone test instrument, comprising means for connecting the test instrument to a telephone circuit; an internal energy supply; means for measuring a voltage produced by the energy supply; and means, responsive to the means for measuring, for signaling the voltage measurement without an alphabetical or numerical display.

The present invention provides a telephone test instrument, comprising: means for connecting the test instrument to a telephone circuit; an internal energy supply; a voice communication circuit operable in either a monitor mode or a talk mode; voice communication circuit switch means for selectably connecting the voice communication circuit to the means for connecting in either the monitor mode or the talk mode; energy supply switch means for selectably connecting the energy supply to provide energy to the instrument; and a data processor connected to the voice communication circuit switch means and the energy supply switch means and programmed for operating the energy supply switch means to connect the energy supply to provide energy to the instrument in response to the voice communication circuit switch means connecting the voice communication circuit to the means for connecting in the talk mode.

The present invention provides a telephone test instrument, comprising: a receiver; a transmitter; means for connecting the receiver and the transmitter to a telephone circuit; and means for measuring loop current through the test instrument, the means for measuring connected to the means for connecting so that loop current is measured while the receiver and transmitter are connected to the telephone circuit. This telephone test instrument in a preferred embodiment further comprises means, responsive to the means for measuring loop current, for signaling a loop current measurement without an alphabetical or numerical display.

The present invention provides a telephone test instrument, comprising a housing; an electrically conductive hook connected to the housing; means, retained by the housing, for connecting the instrument to a telephone circuit; and a switch mounted on the housing, the switch including two terminals, one of the terminals connected to the hook and the other of the terminals connected to the means for connecting so that the telephone circuit is electrically grounded in response to touching the hook to an electrical ground and closing the switch.

The present invention provides a telephone test instrument operable in either a loudspeaker-on mode or a loudspeaker-off mode, comprising: a housing; a receiver disposed in the housing; a loudspeaker disposed in the housing; means for operating the receiver at a base level in response to a signal received by the test instrument over a telephone circuit during the loudspeaker-off mode; means for operating the loudspeaker in response to a signal received by the test instrument over the telephone circuit during the loudspeaker-on mode; and means for operating the receiver at a level not less than the base level during the loudspeaker-on mode.

The present invention provides a telephone test instrument, comprising: a receiver; a transmitter; circuit means for connecting the receiver and transmitter to tip and ring lines of a telephone circuit so that loop current of the telephone circuit flows through the instrument, the circuit means including: a positive temperature coefficient resettable fuse; a triac connected to the fuse so that the fuse and the triac are connected in series across the tip and ring lines of the telephone circuit in response to connection of the instrument to the tip and ring lines; and means, connected to the triac, for activating the triac to be conductive in response to a predetermined magnitude of loop current flowing through the instrument so that the loop current flows through the series connected fuse and triac.

Therefore, from the foregoing, it is a general object of the present invention to provide a novel and improved telephone test instrument. Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art when the following description of the preferred embodiment is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B show one external side view of a telephone test instrument constructed in accordance with the preferred embodiment of the present invention.

FIG. 1C shows an enlarged view of a keypad portion shown in FIGS. 1A and 1B.

FIG. 2 shows an external side view along line 2--2 shown in FIG. 1.

FIG. 3 shows an external side view of the telephone test instrument along line 3--3 shown in FIG. 2.

FIG. 4 is an external side view along line 4--4 shown in FIG. 1.

FIG. 4A is a view of connectors by which the telephone test instrument can be connected to a telephone circuit.

FIGS. 5A-5B are a functional block and schematic diagram of an analog section of the preferred embodiment of the telephone test instrument of the present invention.

FIG. 6 is a functional block and schematic diagram of a digital section of the preferred embodiment of the telephone test instrument or the present invention.

FlGS. 7A-7D are a schematic circuit diagram of the preferred embodiment of the analog and digital sections of the telephone test instrument of the present invention, excluding at least part of the ringer, ground start and over-current protection circuits.

FIG. 8 is a schematic circuit diagram of the preferred embodiment ringer, ground start and over-current protection circuits not shown in FIGS. 7A-7D.

FIGS. 9A-9H are flow charts of a program for controlling a microprocessor of the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the telephone test instrument of the present invention is a microprocessor-controlled, high-impact plastic, rugged unit for voice frequency transmission and operational tests of trunk circuits and subscriber lines in a telephone network. With appropriate end clips or plugs, this embodiment can be used by either outside plant or central office personnel. Although the present invention is not limited to a telephone test instrument which includes all of these features or those subsequently described, the features of the preferred embodiment will be described with reference to a single instrument because the presently preferred embodiment includes them. This preferred embodiment, having an external appearance and generally identified by the reference numeral 2 in FIGS. 1-4, includes the following features:

An amplifier/speaker with three distinct audio levels provides hands-free listening/monitoring. The speaker is powered by an internal energy supply. If there is sufficient loop current, the energy supply is automatically recharged when the test instrument is connected to a line and the instrument is in the talk mode. During amplifier/speaker operation, an earpiece receiver remains enabled. Amplifier/speaker operation is stopped or prevented if the automatically, continually monitored voltage of the internal energy supply is too low.

A microprocessor provides additional features which are controlled by dual-function keys on a keypad. The microprocessor permits operational variations, such as speed of dialing and percentage of break in pulse dialing and frequency in tone dialing, to be made.

A repertory dialer will store ten 27-digit numbers with dial modes (tone or pulse). A credit card number and a selectable pause time can be stored along with the number to be called. The last number called can be automatically redialed in either tone or pulse mode.

A talk/monitor switch permits talking and monitoring on a connected line.

A tone/pulse/out switch selects either DTMF (Dual Tone Multi-Frequency) or DP (dc Dial Pulse) pulsing. A third position of the switch disconnects non-essential circuits to extend the range of the set for listening/talking only.

A push-button mute switch allows the user to cut off the transmitter to improve reception in noisy locations The call will remain muted as long as the mute switch is depressed. The switch also prevents the called person from hearing the caller's private conversation with someone nearby.

A tone ringer circuit provides an audible ringing signal when the set is in the monitor mode.

A ground start switch provides for originating calls when a ground start condition is required.

A spring-loaded belt hook provides a secure connection to a belt loop or "D" ring for a convenient way to carry or store the test set. The belt hook is used as a reference ground path for the optional ground start function.

In the monitor