CA1128222A - Lineman's hand test set - Google Patents
Lineman's hand test setInfo
- Publication number
- CA1128222A CA1128222A CA322,913A CA322913A CA1128222A CA 1128222 A CA1128222 A CA 1128222A CA 322913 A CA322913 A CA 322913A CA 1128222 A CA1128222 A CA 1128222A
- Authority
- CA
- Canada
- Prior art keywords
- lineman
- test set
- hand test
- tone
- rotary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/22—Arrangements for supervision, monitoring or testing
- H04M3/26—Arrangements for supervision, monitoring or testing with means for applying test signals or for measuring
- H04M3/28—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor
- H04M3/32—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for lines between exchanges
- H04M3/323—Automatic routine testing ; Fault testing; Installation testing; Test methods, test equipment or test arrangements therefor for lines between exchanges for the arrangements providing the connection (test connection, test call, call simulation)
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/24—Arrangements for testing
Abstract
Abstract of the Disclosure The present invention comprises a lineman's hand test set which will simultaneously generate both tone impulses for tone dialing as well as dial pulses for rotary dialing, the rotary dialing or the tone dialing being inhibited depending on the type of telephone the lineman is working with.
Description
~I~L2B~2Z
Description LINEMAN'S HAND TEST SET
The present invention is directed ko an imprc~ed lineman's and central office telephone test hand set.
More particularly, the invention provides an improved lineman's hand set which may be used ~or both rotary dial pulses and push button dial tones. With the growing popularity of push button telephone dialing, it has been difficult for a test lineman to test both rotary dial pulses and push button tone dialing. It is often necessary for a lineman to have two sets of test equipment,-one for rotary dialing and the other for push button tone dialing, The present invention provides an improved test lineman's hand set which has a touch tone pad which may be used both for rotary dialing and push button tone dialing, Another object of the present inventi~ is the provision of àn improved lineman's test set which may be used either for monitoring or for normal telephone - operation.
Another object of the present invention is the provision of sn improved lineman's test se~ which provides for a line polarity indicator.
Another object of the present invention is the provision of an improved lineman~s test set which provides for sn incoming ring indication.
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Another object of the present invention is the pro-vision of an improved lineman's test set which provides fo~ an automatic number re-dialing in the rotary mode o~ the last number dialed.
Another object of the present invention is the pro-vision of an improved hand set in which plug in-line connections are provided for both outside or central office operation.
According to the present invention, there is provided a lineman's hand test set for generating digital and rotary tones to a telephone network having a transmitter ana a receiver comprising a single tone generating mechanism, a rotary tone encoder, a digital tone encoder, each encoder being operatively connected to the tone generating mechanism, a switch circuit operatively connected to each of said encoders and to the tele-phone network, generation of tones by said tone generator mechanism pulsing signals to each encoder, control means inter-posed between each encoder and said switch circuit, the control means being disabled from its particular encoder depending on whether rotary tones or digital tones are desired whereby either rotary tones or digital tones are passed by the undisabled con-trol means to the switch circuit to the telephone network.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification~
wherein:
Description LINEMAN'S HAND TEST SET
The present invention is directed ko an imprc~ed lineman's and central office telephone test hand set.
More particularly, the invention provides an improved lineman's hand set which may be used ~or both rotary dial pulses and push button dial tones. With the growing popularity of push button telephone dialing, it has been difficult for a test lineman to test both rotary dial pulses and push button tone dialing. It is often necessary for a lineman to have two sets of test equipment,-one for rotary dialing and the other for push button tone dialing, The present invention provides an improved test lineman's hand set which has a touch tone pad which may be used both for rotary dialing and push button tone dialing, Another object of the present inventi~ is the provision of àn improved lineman's test set which may be used either for monitoring or for normal telephone - operation.
Another object of the present invention is the provision of sn improved lineman's test se~ which provides for a line polarity indicator.
Another object of the present invention is the provision of an improved lineman~s test set which provides for sn incoming ring indication.
32~:Z
Another object of the present invention is the pro-vision of an improved lineman's test set which provides fo~ an automatic number re-dialing in the rotary mode o~ the last number dialed.
Another object of the present invention is the pro-vision of an improved hand set in which plug in-line connections are provided for both outside or central office operation.
According to the present invention, there is provided a lineman's hand test set for generating digital and rotary tones to a telephone network having a transmitter ana a receiver comprising a single tone generating mechanism, a rotary tone encoder, a digital tone encoder, each encoder being operatively connected to the tone generating mechanism, a switch circuit operatively connected to each of said encoders and to the tele-phone network, generation of tones by said tone generator mechanism pulsing signals to each encoder, control means inter-posed between each encoder and said switch circuit, the control means being disabled from its particular encoder depending on whether rotary tones or digital tones are desired whereby either rotary tones or digital tones are passed by the undisabled con-trol means to the switch circuit to the telephone network.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification~
wherein:
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Fig. 1 is a perspective view of the hand set which is used in connection with the present invention.
Fig. 2 is a schematic diayrammatic view of the cir-cuitry of the present invention.
Fig. 3 is a schematic view showing a modification which comprises a reverse battery indicator.
Fig. 4 shows a schematic view which permits use of a ground start line.
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Fig. 5 is a schematic view showing a modifica-tion which includes a polarity guard.
Referring more part;cularly to Fig. 1, the hand test set of the present invention comprises the usual hand set S cornprising a transmitter T at one end and a receiver U at the other end Digital push buttons P are provided between the two ends with a rotary/tone switch SWl and a monitorttalk switch SW2 being provided. ~t will be seen that wi~h this tool, the lineman can use a single hand set for both rotary dialing pulses and push button dialing tones and for both monitoring or talking.
In general, the present invention, as shown in Fig. 2, comprises the keyboard P which is connected to digital generator ICl and to rotary generator IC3 through a converter IC2. When any of the buttons of the keyboard P are depressed, tones are simultaneously generated in ICl and in IC3. Through the circuit which will be described in greater detail hereinafter~ the tones, whether they are digital from ICl or rotary from IC3, are used to 2Q trigger transistor switch circuit Q6 and Q7 which msy be a Darlington switch, in order to transmit those signals to the telephone network.
Switch circuit Q6 and Q7 is powered either by transistor Q12, when digital tones are desired, or transistc Q8, when rotary tones are desired. When a digital tone dialing is desired, Q~ is both mechanically turned off and electrically turned off and Q12 is ~hysically connected to t and Q7 so that impulses from ICl effect Q6and Q7. When ro~
~z~z dialing is desired, Q6 and Q7 is physically disconnected from Q12 and Q8 is physically and electrically connected to IC3 so that the rotary pulses of IC3 are used to pass current to Q6 and Q7 to convey rotary pulse inorm~tlon to the teIephone lines. It will thus be seen that in either event, the keyboard P will activate ~oth rotary and digital signals with one beLng inhibited The components of a standard telephone network are shown in Fig. 2 and comprise a transmitter T and a receiver U. Diode assembly SVl, resistors Rl and R2 (39 ohm and 22 ohm respectively~, condenser Cl (1.5MFD) and the four windings 37, 31, 38 and 34 of the transformer Tl are also included as standard parts and, in accordance with the'present invention, the components are arranged in a manner similar to the arrangement in a telephone network.
A cut-off transistor Qll ~MPF 102) for the receiver is arranged to cut-off ~he signals to the earpiece - UI of thé'receiver U, when a pulse appears across the TIP
and RING terminals. This occurs either when there is a break'or interruption in the current from ~he telephone line or when the transistor assembly Q6-Q7 turns off the current through the entire network. The current supplied to the'network'from the telephone line is assured of being of correct polarit~ because of the presence of the reverse polarity detector Q10. If the polari~y is reverse, the reverse polarity detec~or Q10 operates ~o turn on indicator DSl to-alert the operator that there is a reverse'polarity. When current is interrupted as set forth abo~e,' a positive potential is created on the gate of transistor Qll through resistors R3 (62 K ohm) and R5 ~62 K ohm~ which will turn Qll off thus silencing the earpiece.
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This will in turn lower but not remove entirely audible dialing clicks, which may irritate or possibly damage the user's ear. Since the level o~ clicks is approximatel~
20 dBM during dialing the user can hear the dialing to assure the user of the functional operation of the unit.
Voice frequency filtering capacitor C2 (.lMFD) will decrease distortion of voice frequencies to Ul by placing a D.C. voltage on the gate of Qll during normal operation. Capacitor C4 (.047) removes R.F. generation of diode D5 biasing on the gate of Qll by being placed in parallel with Qll. Resistor R6 (lOk) in parallel with earpiece Ul limits transient voltages across Qll when it is in the off condition.
The time constants in Cl and R3 are set to stop the receiver Ul for approximately 25 MS which is ample for make and break times during outgoing dialing.
The Talk/Monitor switch SW2 comprises two segments SW2A and SW2B which are used to remove the current path and to raise the input impedance of the network, The segment SW2B, which is in series with the transmitter Tl, breaks the D.C. current path, while the segment SW2A, which is in series with Rl, changes the input impedance by break;ng the low side of the diferential hybrid circuit of the transformer. This input impedance is raised from about 1150 ohms to approximately 10 K ohms.
The of-normal switch SW3 has three segments SW-~A, S~B and SW3C. The segment SW3C which is across winding 37 ~z~z~z and pin ~ of the transformer Tl shorts the differential hybrld circuit and transmitter so that when tone dialing, transis~or Q6 connects wi~h the telephone lines through a low lmpedance.
Also during tone dialing, transformer Tl is shorted so ~hat extraneous signals are not placed on the l;ne from audible sources. The diode D2 assures proper monitoring in both reversed and normal polarities of use.
Reverse polarity indicator, DSl, turns on when a negative potential appears on the TIP side of the telephone lines by turning on Q10 through diode ~1 and resistors R7 ~lOO K ohm) and R8 (~.7 K ohm). I~en 30 volts or more appears on R7 transistor Q10 will turn on supplying the battery voltage fro~ battery B through R9 ~58 ohm) to the reverse polarity indicator DSl.
The battery B is filtered and lowered in impedance by the capacitor C5 which is in parallel with it. The capacitor C5 is in series with the segment SW3A of the off/norm. switch SW3 to provide a 1 minute time constant for transistor Q9. Q9 is turned on whenever any button of the keyboard is depressed, supplying 6 volts from battery B to the tone and rotary generators~
Emitter follo~ circuit Q6 and Q7 form a medium high current switch capable of on-off switching when under control of transistor Q8 and rotary/tone switch segment SWl or an emitter follower when controlled by the off/norm switch SW3 and rotary/tone switch SWl biased by the operational amplifier.
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When tone push button dia~ing the rotary/tone switch SWl is placed in the tone position and as shown in the drawing segment SWlA is open and SWlB is closed so that a ground is placed on the base of Q7 through segmen~
SW3B (shown closed) of the off/norm switch SW3. Q8 hase is grounded through a resistor R10 (51K) and is of~. When any button of the keyboard P is depressed, the tone generator ICl and rotary generator IC2 and IC3 will simultaneously obtain power and simultaneously generate both rotary and tone dialing corresponding with the button pushed. ~ ~
Tone impulses are fed to the TONE lead through a resistor Rll with a bias voltage of about 3 volts. Since the contacts of the off/norm switch segment SW3C are open, the tone signal will pass to the base of Q7. In turn, its emitter will follow the A.C. portion, riding on a bias of about 3 volts of the tonè signal. The tone signal is then impressed to a low impedance network, through Tl, înto the telephone lines. The dial pulse generator signal from IC3 on line OPL will go to an open segment SULA of the rotary/tone switch SWl and not effect the tone output.
When rotary dialing, the rotaryltone switch segment SWl in the rotary position with segment SWlA closed and SWlB open dial pulses occur at IC2 and IC3 as well as ICl when any button of the keyboard P is pushed, Since SWlB
segment is open the output of ~6~ has no effect on Q7. A
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corresonding pulse appears on OPL input lead through IC3 and to transistor Q8 through closed segment SWlA and ~3, Transistor Q8 which was on, due to the resistor R12 (100 K) on ;ts base, turns on and o. Q8 then supplies a ground or an open circuit to Q7. Q7 has a base resistor R13 o~
200 K ohms so that when Q8 is off, Q7 will also turn off.
This removes the base voltage from Q6, which breaks the current flow through the network to the telephone lines.
Q7 and Q6 will foll~w the pulse placed on Q8, making current pulses as in normal outgoing dialing. The grounded off/norm switch segment SW~B in the TONE input lead does not appear to the base of Q7 because the rotary/tone switch segment SWlB is open.
In either position of the rotary/tone switch, when power to the tone generator TCl or rotary generator IC2 and IC3 is removed due to the 1 minute timer circuit, the c;rcuit of Q7-Q6 will remain on~ If the rotary/tone switch SWl is in the tone position (SWlB segment closed and SWLA
open) ground is placed to the base of Q7, keeping Q6 and Q7 on. If the rotary/tone switch SWl is in the rotary position (SWlB segment open and SWLA closed) a positive voltage is placed on Q8 and Q8 will turn on, resulting in Q6 cnd Q7 turning on. This maintains current flow in the network during conversation after dialing has occurred.
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Depression of the keyboard makes two connections simultaneously to ground forming a 2 of 8 combination to supply generators ICl and IC2 (MC14410 and MC14419) with coded ;n~ormatian, The ICl is a 2 of 8 tone encoder whioh provides an ou~pu~
that is digitally synthesized and filtered. The tones are amplified by an amplifier Al and sent to the output stage Q6 and Q7. The ICl has two outputs, a low tone group and high tone group. These tones are generated simultaneously from pins 2 and 15 and are crystal controlled by a 1 megahertz oscillator CRl.
The filter circuit is comprise~ of the summing i of resistors R14 and R15 (20 K ohm each) and D.C. referenced to ground in resistor R16 (~Q K ohm). Capacitors C6 (.47MFD) and C7 (.15 MFD) with resistors R17 and R16 comprise a 2 stage R.C. filter.
Coupling capacitor C8 (.47 MFD) and resistor R18 (3 K ohm) with resistor Rl9 (100 K ohm) of the operational amplifier Al sets the gain, which may be a gain of approximately 53. The signal enters the inverting input on pin 2 of amplifier Al. A reference vôltage is generated through a resistor dividèr biasing network R20 and R21 (33 K each~ and applied to pin 3 of amplifier Al. Program currents resistors R22 and R23 (100 K and 22 K) set the current of the operating amperage as low as possible and maintain a low output impedance from pin 6 of amplifier Al. The output is then sent to the transistors Q6 and Q7.
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The I~2 converts 2 of 8 push button codes from the keyboard to binary rotary codes for use by the IC3 (MC 14409). Its input oscillator Ll on pin 15 is set to a frequency of about 15.9~ kilohertz. This derives proper timing for elimination of contact bounce and gives sequence timing for input to output control.
IC3 converts binary information ~o outpulsing dial rotary signals, which are fed to output switch segmentSWlA and transistors Q6, Q7 and Q8 through D3 on the !, 10 OPL line, T;ming of make/break ratios are controlled by the 15.96 kilohertz L.C. oscillator and via programming pins.
Provision for number re-dial and auto dialing for up to 16 numbers are contained in memory circuits of the IC3. Re-dial is selected through the gated circuit IC4 which comprises a plurality of NOR gates and includes a logic inverter. The last numbe,r entered into the keyboard P
may be re-dialed when the ~ button is depressed. This action also prevents a new number from being dialed.
Recall occurs when a * button is depressed by placin~ a fixed D.C. voltage on Q8 from the OPL line through pin 4 of IC4. This also resets memory registers of IC3 and allows a new number to be dialed in the IC3. Depression of the * button also disconnects Q12 to prevent any impulses from Al to reach Q6-Q7.
~28ZZ;2 As indicated above, when it is desired to operate with both modes~ the * button is first depressed to reset all the memories and to interrupt current to Q12 and Q8 through IC4. When dialing occurs by depres~i~g the keys of the keyboard, Q8 has been physically and electrically disconnected and Q12 has been physically connected to Q6 and Q7. Tones from ICl are first filtered and then amplified and sent through transistor Q12 to ef~ect Q6 and Q7 which then feeds the tones to the telephonP network.
When it is desired to use rotary dialing, the switches are reset so that Q12 is physically disconnected from Q6 and Q7 and Q8 is physically and electrically connected to IC3. Signals from the keyboard converted by IC2 are sent through the OPL line to Q8 which in turn will activate Q6 and Q7 to provide rotary dialing to the telephone network.
Several modifications or additions may be used with the invention.
In Fig. 3, the circuit may be modified in order to eliminate the battery and use a line power f~r the LED. In this event, the Q10 as well as the L~D is impressed across the telephone lines as indicated. Included are zener D 20 and capacitor C 20.
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In Fig. 4, there is shown a circuit which can be used when the telephone lines include a ground start line.
The circuit i5 impressed across the ground start lineA
from pin 11 and the ring line o the telephone network, The circuit includes a transistor A 20 and resistors R20 and R21.
Fig. S shows another modification in the form of a bridge rectifier circuit which is placed across the telephone network to assure proper polarity. The bridge circuit includes diodes D 21, D 22, D 23 and D 24.
As many and varied modifications of the subject m~tter of this invention will become apparent to those ., skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto.
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Fig. 1 is a perspective view of the hand set which is used in connection with the present invention.
Fig. 2 is a schematic diayrammatic view of the cir-cuitry of the present invention.
Fig. 3 is a schematic view showing a modification which comprises a reverse battery indicator.
Fig. 4 shows a schematic view which permits use of a ground start line.
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Fig. 5 is a schematic view showing a modifica-tion which includes a polarity guard.
Referring more part;cularly to Fig. 1, the hand test set of the present invention comprises the usual hand set S cornprising a transmitter T at one end and a receiver U at the other end Digital push buttons P are provided between the two ends with a rotary/tone switch SWl and a monitorttalk switch SW2 being provided. ~t will be seen that wi~h this tool, the lineman can use a single hand set for both rotary dialing pulses and push button dialing tones and for both monitoring or talking.
In general, the present invention, as shown in Fig. 2, comprises the keyboard P which is connected to digital generator ICl and to rotary generator IC3 through a converter IC2. When any of the buttons of the keyboard P are depressed, tones are simultaneously generated in ICl and in IC3. Through the circuit which will be described in greater detail hereinafter~ the tones, whether they are digital from ICl or rotary from IC3, are used to 2Q trigger transistor switch circuit Q6 and Q7 which msy be a Darlington switch, in order to transmit those signals to the telephone network.
Switch circuit Q6 and Q7 is powered either by transistor Q12, when digital tones are desired, or transistc Q8, when rotary tones are desired. When a digital tone dialing is desired, Q~ is both mechanically turned off and electrically turned off and Q12 is ~hysically connected to t and Q7 so that impulses from ICl effect Q6and Q7. When ro~
~z~z dialing is desired, Q6 and Q7 is physically disconnected from Q12 and Q8 is physically and electrically connected to IC3 so that the rotary pulses of IC3 are used to pass current to Q6 and Q7 to convey rotary pulse inorm~tlon to the teIephone lines. It will thus be seen that in either event, the keyboard P will activate ~oth rotary and digital signals with one beLng inhibited The components of a standard telephone network are shown in Fig. 2 and comprise a transmitter T and a receiver U. Diode assembly SVl, resistors Rl and R2 (39 ohm and 22 ohm respectively~, condenser Cl (1.5MFD) and the four windings 37, 31, 38 and 34 of the transformer Tl are also included as standard parts and, in accordance with the'present invention, the components are arranged in a manner similar to the arrangement in a telephone network.
A cut-off transistor Qll ~MPF 102) for the receiver is arranged to cut-off ~he signals to the earpiece - UI of thé'receiver U, when a pulse appears across the TIP
and RING terminals. This occurs either when there is a break'or interruption in the current from ~he telephone line or when the transistor assembly Q6-Q7 turns off the current through the entire network. The current supplied to the'network'from the telephone line is assured of being of correct polarit~ because of the presence of the reverse polarity detector Q10. If the polari~y is reverse, the reverse polarity detec~or Q10 operates ~o turn on indicator DSl to-alert the operator that there is a reverse'polarity. When current is interrupted as set forth abo~e,' a positive potential is created on the gate of transistor Qll through resistors R3 (62 K ohm) and R5 ~62 K ohm~ which will turn Qll off thus silencing the earpiece.
;' 4 ~L~Z8Z~
This will in turn lower but not remove entirely audible dialing clicks, which may irritate or possibly damage the user's ear. Since the level o~ clicks is approximatel~
20 dBM during dialing the user can hear the dialing to assure the user of the functional operation of the unit.
Voice frequency filtering capacitor C2 (.lMFD) will decrease distortion of voice frequencies to Ul by placing a D.C. voltage on the gate of Qll during normal operation. Capacitor C4 (.047) removes R.F. generation of diode D5 biasing on the gate of Qll by being placed in parallel with Qll. Resistor R6 (lOk) in parallel with earpiece Ul limits transient voltages across Qll when it is in the off condition.
The time constants in Cl and R3 are set to stop the receiver Ul for approximately 25 MS which is ample for make and break times during outgoing dialing.
The Talk/Monitor switch SW2 comprises two segments SW2A and SW2B which are used to remove the current path and to raise the input impedance of the network, The segment SW2B, which is in series with the transmitter Tl, breaks the D.C. current path, while the segment SW2A, which is in series with Rl, changes the input impedance by break;ng the low side of the diferential hybrid circuit of the transformer. This input impedance is raised from about 1150 ohms to approximately 10 K ohms.
The of-normal switch SW3 has three segments SW-~A, S~B and SW3C. The segment SW3C which is across winding 37 ~z~z~z and pin ~ of the transformer Tl shorts the differential hybrld circuit and transmitter so that when tone dialing, transis~or Q6 connects wi~h the telephone lines through a low lmpedance.
Also during tone dialing, transformer Tl is shorted so ~hat extraneous signals are not placed on the l;ne from audible sources. The diode D2 assures proper monitoring in both reversed and normal polarities of use.
Reverse polarity indicator, DSl, turns on when a negative potential appears on the TIP side of the telephone lines by turning on Q10 through diode ~1 and resistors R7 ~lOO K ohm) and R8 (~.7 K ohm). I~en 30 volts or more appears on R7 transistor Q10 will turn on supplying the battery voltage fro~ battery B through R9 ~58 ohm) to the reverse polarity indicator DSl.
The battery B is filtered and lowered in impedance by the capacitor C5 which is in parallel with it. The capacitor C5 is in series with the segment SW3A of the off/norm. switch SW3 to provide a 1 minute time constant for transistor Q9. Q9 is turned on whenever any button of the keyboard is depressed, supplying 6 volts from battery B to the tone and rotary generators~
Emitter follo~ circuit Q6 and Q7 form a medium high current switch capable of on-off switching when under control of transistor Q8 and rotary/tone switch segment SWl or an emitter follower when controlled by the off/norm switch SW3 and rotary/tone switch SWl biased by the operational amplifier.
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When tone push button dia~ing the rotary/tone switch SWl is placed in the tone position and as shown in the drawing segment SWlA is open and SWlB is closed so that a ground is placed on the base of Q7 through segmen~
SW3B (shown closed) of the off/norm switch SW3. Q8 hase is grounded through a resistor R10 (51K) and is of~. When any button of the keyboard P is depressed, the tone generator ICl and rotary generator IC2 and IC3 will simultaneously obtain power and simultaneously generate both rotary and tone dialing corresponding with the button pushed. ~ ~
Tone impulses are fed to the TONE lead through a resistor Rll with a bias voltage of about 3 volts. Since the contacts of the off/norm switch segment SW3C are open, the tone signal will pass to the base of Q7. In turn, its emitter will follow the A.C. portion, riding on a bias of about 3 volts of the tonè signal. The tone signal is then impressed to a low impedance network, through Tl, înto the telephone lines. The dial pulse generator signal from IC3 on line OPL will go to an open segment SULA of the rotary/tone switch SWl and not effect the tone output.
When rotary dialing, the rotaryltone switch segment SWl in the rotary position with segment SWlA closed and SWlB open dial pulses occur at IC2 and IC3 as well as ICl when any button of the keyboard P is pushed, Since SWlB
segment is open the output of ~6~ has no effect on Q7. A
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corresonding pulse appears on OPL input lead through IC3 and to transistor Q8 through closed segment SWlA and ~3, Transistor Q8 which was on, due to the resistor R12 (100 K) on ;ts base, turns on and o. Q8 then supplies a ground or an open circuit to Q7. Q7 has a base resistor R13 o~
200 K ohms so that when Q8 is off, Q7 will also turn off.
This removes the base voltage from Q6, which breaks the current flow through the network to the telephone lines.
Q7 and Q6 will foll~w the pulse placed on Q8, making current pulses as in normal outgoing dialing. The grounded off/norm switch segment SW~B in the TONE input lead does not appear to the base of Q7 because the rotary/tone switch segment SWlB is open.
In either position of the rotary/tone switch, when power to the tone generator TCl or rotary generator IC2 and IC3 is removed due to the 1 minute timer circuit, the c;rcuit of Q7-Q6 will remain on~ If the rotary/tone switch SWl is in the tone position (SWlB segment closed and SWLA
open) ground is placed to the base of Q7, keeping Q6 and Q7 on. If the rotary/tone switch SWl is in the rotary position (SWlB segment open and SWLA closed) a positive voltage is placed on Q8 and Q8 will turn on, resulting in Q6 cnd Q7 turning on. This maintains current flow in the network during conversation after dialing has occurred.
~282ZZ
Depression of the keyboard makes two connections simultaneously to ground forming a 2 of 8 combination to supply generators ICl and IC2 (MC14410 and MC14419) with coded ;n~ormatian, The ICl is a 2 of 8 tone encoder whioh provides an ou~pu~
that is digitally synthesized and filtered. The tones are amplified by an amplifier Al and sent to the output stage Q6 and Q7. The ICl has two outputs, a low tone group and high tone group. These tones are generated simultaneously from pins 2 and 15 and are crystal controlled by a 1 megahertz oscillator CRl.
The filter circuit is comprise~ of the summing i of resistors R14 and R15 (20 K ohm each) and D.C. referenced to ground in resistor R16 (~Q K ohm). Capacitors C6 (.47MFD) and C7 (.15 MFD) with resistors R17 and R16 comprise a 2 stage R.C. filter.
Coupling capacitor C8 (.47 MFD) and resistor R18 (3 K ohm) with resistor Rl9 (100 K ohm) of the operational amplifier Al sets the gain, which may be a gain of approximately 53. The signal enters the inverting input on pin 2 of amplifier Al. A reference vôltage is generated through a resistor dividèr biasing network R20 and R21 (33 K each~ and applied to pin 3 of amplifier Al. Program currents resistors R22 and R23 (100 K and 22 K) set the current of the operating amperage as low as possible and maintain a low output impedance from pin 6 of amplifier Al. The output is then sent to the transistors Q6 and Q7.
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The I~2 converts 2 of 8 push button codes from the keyboard to binary rotary codes for use by the IC3 (MC 14409). Its input oscillator Ll on pin 15 is set to a frequency of about 15.9~ kilohertz. This derives proper timing for elimination of contact bounce and gives sequence timing for input to output control.
IC3 converts binary information ~o outpulsing dial rotary signals, which are fed to output switch segmentSWlA and transistors Q6, Q7 and Q8 through D3 on the !, 10 OPL line, T;ming of make/break ratios are controlled by the 15.96 kilohertz L.C. oscillator and via programming pins.
Provision for number re-dial and auto dialing for up to 16 numbers are contained in memory circuits of the IC3. Re-dial is selected through the gated circuit IC4 which comprises a plurality of NOR gates and includes a logic inverter. The last numbe,r entered into the keyboard P
may be re-dialed when the ~ button is depressed. This action also prevents a new number from being dialed.
Recall occurs when a * button is depressed by placin~ a fixed D.C. voltage on Q8 from the OPL line through pin 4 of IC4. This also resets memory registers of IC3 and allows a new number to be dialed in the IC3. Depression of the * button also disconnects Q12 to prevent any impulses from Al to reach Q6-Q7.
~28ZZ;2 As indicated above, when it is desired to operate with both modes~ the * button is first depressed to reset all the memories and to interrupt current to Q12 and Q8 through IC4. When dialing occurs by depres~i~g the keys of the keyboard, Q8 has been physically and electrically disconnected and Q12 has been physically connected to Q6 and Q7. Tones from ICl are first filtered and then amplified and sent through transistor Q12 to ef~ect Q6 and Q7 which then feeds the tones to the telephonP network.
When it is desired to use rotary dialing, the switches are reset so that Q12 is physically disconnected from Q6 and Q7 and Q8 is physically and electrically connected to IC3. Signals from the keyboard converted by IC2 are sent through the OPL line to Q8 which in turn will activate Q6 and Q7 to provide rotary dialing to the telephone network.
Several modifications or additions may be used with the invention.
In Fig. 3, the circuit may be modified in order to eliminate the battery and use a line power f~r the LED. In this event, the Q10 as well as the L~D is impressed across the telephone lines as indicated. Included are zener D 20 and capacitor C 20.
- ~lZ8Z2Z
In Fig. 4, there is shown a circuit which can be used when the telephone lines include a ground start line.
The circuit i5 impressed across the ground start lineA
from pin 11 and the ring line o the telephone network, The circuit includes a transistor A 20 and resistors R20 and R21.
Fig. S shows another modification in the form of a bridge rectifier circuit which is placed across the telephone network to assure proper polarity. The bridge circuit includes diodes D 21, D 22, D 23 and D 24.
As many and varied modifications of the subject m~tter of this invention will become apparent to those ., skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto.
.?. ~
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A lineman's hand test set for generating digital and rotary tones to a telephone network having a transmitter and a receiver comprising a single tone generating mechanism, a rotary tone encoder, a digital tone encoder, each encoder being operatively connected to the tone generating mechanism, a switch circuit operatively connected to each of said encoders and to the telephone network, generation of tones by said tone generator mechanism pulsing signals to each encoder, control means interposed between each encoder and said switch circuit, the control means being disabled from its particular encoder depending on whether rotary tones or digital tones are desired whereby either rotary tones or digital tones are passed by the undisabled control means to the switch circuit to the telephone network.
2. A lineman's hand test set as claimed in claim 1 wherein said tone generating mechanism includes a push button keyboard.
3. A lineman's hand test set as claimed in claim 2 wherein said control means comprises a rotary tone control transistor operatively connected to the rotary tone encoder and a digital tone control transistor operatively connected to said digital tone encoder.
4. A lineman's hand test set as claimed in claim 3 wherein switch means are provided to disconnect said rotary tone control transistor from said switch circuit.
5. A lineman's hand test set as claimed in claim 4 wherein means are provided to disconnect said digital tone control transistor from said switch means.
6. A lineman's hand test set as claimed in claim 5 wherein switch means common to said two control transistors are provided to disconnect both.
7. A lineman's hand test set as claimed in claim 6 wherein the rotary tone control transistor is in circuit with the digital tone control transistor to electrically disable the digital tone control transistor.
8. A lineman's hand test set as claimed in claim 7 wherein said switch means comprise a darlington pair.
9. A lineman's hand test set as claimed in claim 8 wherein the digital tone control transistor is connected to the digital tone encoder through an amplifying circuit.
10. A lineman's hand test set as claimed in claim 9 wherein said amplifying circuit is connected to a filter circuit.
11. A lineman's hand test set as claimed in claim 10 wherein said amplifying circuit is connected to a biasing circuit.
12. A lineman's hand test set as claimed in claim 11 wherein the rotary control transistor is connected to a * button of the keyboard through a gated circuit whereby depression of said * button disables both control transistors.
13. A lineman's hand test set as claimed in claim 12 wherein a reverse polarity detector is provided for said telephone network, voice filtering capacitors and a cut-off transistor are associated with said receiver and a diode is provided for the cut-off transistor.
14. A lineman's hand test set as claimed in claim 13 wherein a resistor is in parallel with the receiver to limit transient voltages across the cut-off transistor.
15. A lineman's hand test set as claimed in claim 14 wherein the transmitter has an input impedance and wherein a talk/monitor switch is provided to break the circuit with the transmitter and to change the input impedance.
16. A lineman's hand test set as claimed in claim 15 wherein an off/normal switch is provided to break the circuit with the transmitter so that the switch means connects with the telephone network at lower impedance.
17. A lineman's hand test set as claimed in claim 16 wherein an LED is provided on the reverse polarity detector and said LED is connected to the network through a diode and a pair of resistors so as to permit voltage to be supplied to the LED.
18. A lineman's hand test set as claimed in claim 17 wherein said LED is operated by line power and includes a zener and a capacitor.
19. A lineman's hand test set as claimed in claim 17 wherein a ground start circuit is included which includes a transistor and a pair of resistors.
20. A lineman's hand test set as claimed in claim 17 wherein a bridge rectifier circuit is included to assure proper polarity.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US914,869 | 1978-06-12 | ||
| US05/914,869 US4194098A (en) | 1978-06-12 | 1978-06-12 | Lineman's hand test set |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1128222A true CA1128222A (en) | 1982-07-20 |
Family
ID=25434889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA322,913A Expired CA1128222A (en) | 1978-06-12 | 1979-03-07 | Lineman's hand test set |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4194098A (en) |
| CA (1) | CA1128222A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2566215B1 (en) * | 1984-06-19 | 1986-10-10 | Semiconducteurs Ste Gle | DEVICE FOR ADAPTING A KEYBOARD WITH DECIMAL OR MULTI-FREQUENCY TRANSMISSION ON A TELEPHONE STATION |
| US4922516A (en) * | 1988-01-25 | 1990-05-01 | Communications Technology Corporation | Telephone technician's terminals with auto-selection of dial pulse on DTMF signalling |
| US4843620A (en) * | 1988-06-29 | 1989-06-27 | Nicollet Technologies, Inc. | Hand-held telephone line signaling test instrument |
| US4868858A (en) * | 1988-08-03 | 1989-09-19 | Harris Corporation | Keypad/dialler interface for telephone test set |
| US5025466A (en) * | 1990-03-13 | 1991-06-18 | Communications Manufacturing Company | Telephone test instrument |
| EP0454316A3 (en) * | 1990-04-23 | 1993-08-18 | Communications Manufacturing Company | Data terminal for communicating over a telephone circuit |
| EP2384260B1 (en) * | 2008-12-30 | 2018-07-04 | Saint-Gobain Abrasives, Inc. | Reinforced bonded abrasive tools |
| CN102446127A (en) * | 2010-10-11 | 2012-05-09 | 鸿富锦精密工业（深圳）有限公司 | Power supply device and method for testing on/off of computer motherboard |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3792205A (en) * | 1971-06-01 | 1974-02-12 | Communic Mfg | Hand held telephone test instrument |
| US3778556A (en) * | 1971-07-02 | 1973-12-11 | Telecommunications Techn Inc | Telephone signaling and testing apparatus with provisions for either pulse or multifrequency dialing |
| US4119810A (en) * | 1976-09-13 | 1978-10-10 | Phone Devices Corporation | Pushbutton telephone apparatus with automatic dialing and combinational sequential control signalling capabilities |
-
1978
- 1978-06-12 US US05/914,869 patent/US4194098A/en not_active Expired - Lifetime
-
1979
- 1979-03-07 CA CA322,913A patent/CA1128222A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4194098A (en) | 1980-03-18 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |