CN2134008Y - Public telephone with calling card - Google Patents

Abstract

The utility model relates to a public telephone with a call card, which is composed of a telephone, a call card, and a control circuit of the call card, wherein the call card is provided with a plurality of fuses, and one of the fuses is burnt out after one-off talking. The control circuit of the call card is composed of nine functional circuits comprising a three minute timing circuit, a signal processing circuit for the called off-hook mode, a telephone control circuit, a talking receiving circuit, a special service telephone circuit, a recognizing circuit for the call card, a circuit for the cancellation and the checking of talking expenses, a circuit for the display and the cancellation of the talking times of the call card, and a current checking circuit for the code of the call card. The true or untrue call card can be recognized, and the available talking times can be recognized. The timing starts after the called telephone is in the off-hook mode. When three minutes are lost, the reminding voice of the end of the talking sends out, and the talking is automatically intermitted by that the users do not continue. The utility model can be used for the types of a programmed control exchange mechanism, a cross exchange mechanism and a step-by-step exchange mechanism. The utility model has the advantage of low cost.

Description

Public telephone with calling card

The utility model relates to a kind of prepaid telephone system, relates to a kind of words card public telephone set or rather.

Existing public telephone system comprises coin telephone and magnetic card type public telephone substantially, and coin telephone has self-clocking metering performance, when using phone, throws the coin of foot regulation and just can connect circuit automatically.Move back coin and some inartful problems because of existence, fail to promote the use of always, and have to transfer to Attended mode.The magnetic card type public telephone uses magnetic card, but is printed on talk times on the card, in the communication process, but constantly shows talk times remaining on the card on the phone display, after the on-hook last talk times is printed on and withdraws from card on the card again.The magnetic card type public telephone costs an arm and a leg, and the keeping quality of magnetic card is poor, also not seen widespread use.

The purpose of this utility model is the advantage of collection coin-feed, magnetic card type public telephone set, design a kind of words card public telephone set, when using phone, insert the words card that contains predetermined talk times, after testing the talk times that true and false Hua do not blocked and be contained, promptly connect telephone line automatically.Words card telephone set has the chronoscope subfunction, is self-clocking behind called off-hook, and upward nullifies a talk times automatically from the words card.Air time sends words automatically and reminds sound eventually after reaching 3 minutes, as also continuing conversation, only need press " continuity key ", and words card phone repeats said process, otherwise just cuts off phone automatically.

Words card public telephone set of the present utility model, (comprise Pulse Electric phone, dual tone phone machine by telephone set, do not comprise the rotary-dial phone machine), words card control circuit and words cards form, described words card is the card that a kind of design has n delivery value, n+2 jack and a mechanical notch are arranged, the n root fuse of making by semiconductor integrated circuit technique is arranged on the insulating substrate of card, and the fuse that once fuses of conversing also has password resistance R X.

Described words card control circuit mainly comprises nine functional circuits: 3 minutes timing circuits that make words card telephone set have the chronoscope subfunction; Handle the called off hook signal treatment circuit of called off hook signal; Control will be talked about the phone control circuit that card control circuit is connected with the telephone set talking and receiving circuit; Control words card telephone set needn't use the special telephone Service Circuit of words card when doing special type service caller; Control words card telephone set makes needn't use when called the Service Circuit of being talked about of words card; The words of distinguishing true from false card, detection have or not the words card identification circuit of talk times; Judge whether to nullify the telephone expenses cancellation testing circuit of talk times; Identification, demonstration are talked about cartoon words number of times and nullify talk times demonstration, the cancellation circuit of once talking about cartoon words number of times after conversations; Differentiate the words clip pin current detection circuit of words card fusing current.

Described phone control circuit is exported the talking and receiving circuit of the machine of answering the call, described special telephone Service Circuit, talked about Service Circuit, the output of words card identification circuit is connected to the input of phone control circuit respectively, described 3 minutes timing circuits, words clip pin current detection circuit, telephone expenses are nullified the input that testing circuit output also is connected to the phone control circuit respectively, telephone expenses are nullified testing circuit output and also are connected to 3 fens timing circuits, the answer the call talking and receiving circuit of machine of described called off hook signal treatment circuit input, the output expense of answering is nullified testing circuit, and described talk times shows nullifies the fuse circuit that circuit is exported the card of answering.

Voltage on the described words card RX send telephone expenses to nullify testing circuit and words card identification circuit, words clip pin current detection circuit shows, nullifies circuit through talk times provides fusing voltage to fuse, the described special telephone Service Circuit input line of answering the call is talked about the Service Circuit input machine talking and receiving circuit of answering the call.

The talking and receiving circuit of phone control circuit connection telephone set at reception special telephone Service Circuit or after being talked about Service Circuit or talking about card identification circuit output signal allows to converse.When the phone control circuit receives after 3 fens timing circuit output signals or words clip pin current detection circuit and telephone expenses nullify the abnormal signal of testing circuit output, close the talking and receiving circuit of telephone set, dropped calls.The off hook signal treatment circuit receives the control of called off hook signal and opens telephone expenses and nullify testing circuit, words clip pin current detection circuit, words cartoon words number of times and nullify circuit, and notify 3 fens timing circuits to pick up counting.The user is as long as card is talked about in off-hook and insertion, but words cartoon words number of times display circuit is with regard to the talk times on the demonstration words card.

Describe technology of the present utility model in detail below in conjunction with the embodiment accompanying drawing

Accompanying drawing 1. words card structure schematic diagrames

3 fens timing circuit electrical schematic diagrams of accompanying drawing 2. words card control circuits

The off hook signal treatment circuit electrical schematic diagram of accompanying drawing 3. words card control circuits

Accompanying drawing 4. words card control circuit electrical schematic diagrams

Fig. 2, Fig. 3, Fig. 4 constitute words card control circuit of the present utility model, and ordinary telephone set is installed these words card control circuit and promptly constituted words card public telephone set.Present embodiment is got n=10.

Referring to accompanying drawing 1, words card 100 contains delivery value 10 times, have mutatis mutandis mechanical slot mouth 101,12 jack 102-113 have 10 fuse 115-124 that make by semiconductor integrated circuit technique on the insulating substrate 114, fuse one end causes respectively on the jack 102-111 with lead, the fuse other end and connect after cause jack 112, and connect end and also connect password resistance R X, RX other end jointing holes 113 is connected with the ground wire of words card control circuit.

When making a phone call, will talk about card 100 and insert words card telephone set, jack 102-113 is connected with the corresponding plug of phone control circuit.

Referring to 2,3 fens timing circuits of accompanying drawing, IC1 is time-base circuit (NE555), and IC2 is a music-integrating block, Y1, Y2 are inverse gate, the B line be high level to capacitor C 1 charge period between, T1 is by, T2 conducting, when the B line is the high level disappearance, capacitor C 1 discharge, discharge time constant is determined by R1.C1.Present embodiment is taken as 3 minutes in accordance with regulations, the IC1 output low level, and T2 ends, and IC2 sends the conversation end of a period through loud speaker Y and reminds sound.Y1, Y2, C2 etc. form 5 seconds time delay circuits, promptly the A line timing in 3 fens to after postpone again 5 second output low level.The function of circuit shown in Figure 2 is behind called off-hook, begins timing in 3 fens, and the time is sent the cutoff call signal to postponing 5 seconds again by the A line.

Referring to accompanying drawing 3, off hook signal treatment circuit, IC3 are frequency-selector (LM567), embodiment frequency-selecting signal is 450Hz, and through busy tone, ring-back tone, the dialing tone startup IC3 work of C3 coupling, the level "0" of its 8 pin output is anti-phase through Y3, deliver to analog switch S1, make it to close, EC gives capacitor C 4 chargings through S1, during called off-hook, the 450Hz blackout, S1 disconnects, the C4 discharge, after embodiment was designed to 1 second, Y4 exported high level, i.e. C line output high level.The function of circuit shown in Figure 3 is at called off-hook after 12 seconds, and control line C is a high level, presses " continuity " K switch 2, and the C line is also exported high level.

Referring to accompanying drawing 4, a, b are that telephone wire, 100 is the words card among the figure, and 200 is telephone set.

Frame of broken lines 1 constitutes the power circuit of words card control circuit.IC4 is the three-terminal voltage-stabilizing device, and S2, S3 are analog switch, constitute 3 seconds delay circuits by T3, T4 etc.Behind user's off-hook, trigger controllable silicon BCR, transformer B has electricity, and EC ' gives T3, T4 power supply, and T3 is by the T4 conducting in 3 seconds, and S2 closes S3 and opens, and EC ' gives capacitor C 5 chargings through S2, and after 3 seconds, T3 conducting T4 ends, and S3 closes S2 and opens, output EC, and EC ' charges to C5 through R2.Light-emitting diode D1 is used in reference to and is shown with.

Frame of broken lines 2 constitutes the phone control circuit, mainly comprises rest-set flip-flop IC5, NAND gate Y5, Y6, or door H1 and analog switch S4, S5.When or three inputs of door H1 have one when " 1 ", H1 export " 1 ", the Q end of IC5 is 1, S4, S5 close, the talking and receiving circuit of connection telephone set 200, the user can converse.When two inputs of Y5 are " 1 " simultaneously, make the input of Y6 be " 0 ", perhaps another input of Y6 (A line) is 0 o'clock, the Q end of IC5 is " 0 ", S4, S5 open, dropped calls, the function of this circuit is as called or do special telephone service caller at words cards telephone set, or insert words card and checking words card correct, connect telephone line when but talk times is arranged, when conversation surpasses 3 minutes or normally do not nullify talk times or used false words card, automatically shut down telephone line in addition.

Frame of broken lines 3 constitutes is talked about Service Circuit, mainly comprises capacitor C 51, C6, analog switch S6 etc.These words cards telephone set is done when called, and phone ringing 25H ' z signal is through diode D2, D3 rectification, and to the C6 charging, S6 closes after 3 seconds at user's off-hook, and S6 output " 1 " signal starts the phone control circuit to the input of phone control circuit or door H1.The function of this circuit is to do needn't use the words card promptly needn't pay when called at words cards telephone set.

Frame of broken lines 4 constitutes the special telephone Service Circuit, mainly comprises counter IC6, differential circuit C7, D4, R3 etc.D5, R4, C8 constitute 1 second delay circuit, in user's off-hook 4 seconds (wherein 3 seconds power up time of delay for EC), when if the first dialing is numeral 1 i.e. pulse, Q0 output " 1 " signal of counter IC6 is to the input of phone control circuit or door H1, start the phone control circuit, all the other dialing numbers except that 1 all do not work to this circuit.The function of this circuit is when making a call spy with 1 beginning with words cards telephone set and obey, and needn't use the words card promptly needn't pay.

Frame of broken lines 5 constitutes words card identification circuit, mainly comprises voltage comparator A1, A2, triode T5, NOR gate H2, inverse gate Y7 etc.The comparative voltage that A1, A2 adjust is respectively U1, U2, when from the UX current potential of words card jack 112 between between U1, U2, A1 or A2 output high level, the T5 conducting, light-emitting diode D6 is bright, the words card that expression is discerned is effective.Press "start" button K1, EC is through R5, K1, diode D7-D16, words card fuse 115-124, and RX goes into ground, makes the input of H2 output " 1 " to phone control circuit or door H1, starts the phone control circuit.Y7 output " 1 " simultaneously represents that the words card has talk times but light light-emitting diode D17.The function of this circuit is after the user inserts the words card, differentiates the words card true and false (UX), and check words card has or not telephone expenses (but talk times) and shows.

Frame of broken lines 6 is nullified testing circuit for telephone expenses, mainly comprises voltage comparator A3, inverse gate Y8, rest-set flip-flop IC7, and analog switch S7 and relay J, the effect of capacitor C 8 is to guarantee when user's off-hook powers on, and the Q of IC7 end is " 0 ", and S7 is disconnected.Voltage U X on the words clip pin resistance R X is " 0 " current potential before fuse does not fuse, A3 exports " 1 ", and Y8 exports " 0 ".By aforementioned, the analysis of the called off hook signal circuit of Fig. 3 as can be known, after 12 seconds, the C line is a high level at user's off-hook, with the IC7 set, S7 closes, the J adhesive makes the 3 fen timing circuits of B line output high potential to Fig. 1 simultaneously.Moment before and after fuse failure, UX voltage produces a saltus step from low to high, the negative saltus step of A3 output, IC7 is put 0 through Y8 is anti-phase, S7 is disconnected, and J is also disconnected, the recovery of B line " " current potential, the transient state positive transition of its Q end output simultaneously is coupled to the input of phone control circuit NAND gate Y5 through capacitor C 9, for Y5 provides enabling signal.The effect of the monostable trigger-action circuit that is made of capacitor C 10 elements such as grade among the figure is the time-delay of generation about 0.15 second, makes the many adhesives of relay J a little while, to guarantee fuse failure.The function of this circuit is to control after 12 seconds at called off-hook to nullify the once talk times of words card.

Frame of broken lines 7 shows, nullifies circuit for words cartoon words number of times, but comprise the talk times display circuit that constitutes by light-emitting diode D18-D27 etc., the telephone expenses of being made up of analog switch S8-S17 etc. are nullified circuit and by inverse gate Y9-Y12, resistance R 6, capacitor C 11, counter IC14(CD4017) wait the telephone expenses cancellation control circuit of forming.

EC goes into ground through D18-D27, fuse 115-124, RX, as long as in the path fuse is arranged, then light-emitting diode is bright, but shows words card talk times.

Y9-Y11, R6, C11 form oscillator, for IC14 provides count pulse, by the aforementioned analysis that telephone expenses are nullified testing circuit 6 as can be known, after 12 seconds, the B line is " 1 " at called off-hook, begins counting through the anti-phase IC14 of making of Y12, high level appears in its Q0-Q9 successively, and S8-S17 is controlled successively to be closed.The fusing voltage U is added on the fuse 115-124 of words card successively by analog switch.Adjust the output pulse period of oscillator, make to be controlled at about 0.2 second.But along with first Zapping circuit in 0.2 second by being switched to fusing, telephone expenses are nullified testing circuit 6 output logoff signal and are disconnected relay J, and through the anti-phase control IC 14 of Y12 stop the counting, unless press " continuity " K switch 2 among Fig. 3, force that the C line is 1, the B line is 1, repeat above-mentioned log off procedure again.The function of this circuit is, to nullify once the talk times and the demonstration words card of words card and go up all talk times after 12 seconds at called off-hook.

Frame of broken lines 8 is words clip pin current detection circuit, mainly comprises the movable contact J1-1 and the capacitor C 12 of voltage comparator A4, relay J.The analysis of nullifying testing circuit 6 by telephone expenses as can be known, called off-hook is relay J6 adhesive after 12 seconds, the voltage of capacitor C 5 voltage U that promptly fuses is added on the words card fuse in the power circuit 1, in the moment blow out fuse, blowout current is controlled at about 0.1A.Under the normal condition, the A4 negative terminal voltage should be higher than positive terminal voltage, if but the user has used non-correct card, cause blowout current incorrect, show as the long not even fusing of fusing time, electric charge on the C5 will be than the time with correct words card residual must lacking, though this moment, UX was even as big as making A3 output negative, cause J to disconnect, but still have electric charge on the C12, the A4 negative terminal voltage is lower than positive terminal voltage, A4 exports high level, the Q that nullifies the IC7 of testing circuit 6 in telephone expenses holds the moment of output positive transition on-level, makes Y5 output " 0 ", control phone control circuit dropped calls.The function of this circuit is, when the user has used the words card identical with the utility model structure, but when RX, fuse, blowout current and former different design, also can detect and dropped calls.

In sum, when using words card telephone set to do called or doing the caller of spy's clothes, needn't insert the words card, user's off-hook can be conversed.When doing caller, first off-hook, after time-delay in 3 seconds, the words card control circuit powers up, and inserts the words card, but shows talk times and identification words card.By behind the "start" button K1, connect telephone set the user, the user can hear that dialing tone begins dialing, sends the 450Hz signal tone here by telephone wire, detects called whether off-hook.Called off-hook applied fusing voltage after 12 seconds, nullified a talk times and began timing in 3 fens.Automatically remove fusing voltage and stop the cancellation action after nullifying telephone expenses, 3 assign to, and the user can hear the whole sound of reminding of words, and operate " continuity " key K2 and can converse again 3 fens, otherwise dropped calls after 5 seconds.

Words card telephone set of the present utility model has the advantage of coin-box telephone set and card phone machine, and with low cost, easy to use, in being particularly suitable for, the small city uses. That these words cards telephone set can be used for is program control, in length and breadth, the step-up exchange standard, the signal tone that local telephone network provides must be 450Hz, for avoiding network application and increase the network load of phone, this control circuit be to power separately, can select 6V/1A or 12V/0.5A power supply.

Claims (3)

1, a kind of words card public telephone set is made up of telephone set, the words card that contains n talk times and words card control circuit, it is characterized in that:

1) the described words card that contains n talk times is the card that n root fuse and password resistance R X are arranged;

2) described words card control circuit mainly comprises 3 minutes timing circuits that make words card telephone set have the chronoscope subfunction, handle the called off hook signal treatment circuit of called off hook signal, control will be talked about the phone control circuit that card control circuit is connected with the telephone set talking and receiving circuit, control words card telephone set needn't use the special telephone Service Circuit of words card when doing special type service caller, control words card telephone set makes needn't use when called the Service Circuit of being talked about of words card, the words of distinguishing true from false card detects the words card identification circuit that has or not talk times, judge whether to nullify the telephone expenses cancellation testing circuit of talk times, the talk times that identification shows words cartoon words number of times and cartoon words number of times is once talked about in cancellation after conversation shows nullifies circuit, differentiate the words clip pin current detection circuit of words card fusing current, described phone control circuit is exported the talking and receiving circuit of the machine of answering the call, described special telephone Service Circuit, talked about Service Circuit, the output of words card identification circuit is connected to the input of phone control circuit respectively, described 3 minutes timing circuits, words clip pin current detection circuit, telephone expenses are nullified the input that testing circuit output also is connected to the phone control circuit respectively, telephone expenses are nullified testing circuit output and also are connected to 3 fens timing circuits, the answer the call talking and receiving circuit of machine of described called off hook signal treatment circuit input, the output expense of answering is nullified testing circuit, described talk times shows nullifies the fuse circuit that circuit is exported the card of answering, voltage on the described words card RX send telephone expenses to nullify testing circuit and words card identification circuit, words clip pin current detection circuit shows that through talk times nullifying circuit provides fusing voltage to fuse, the described special telephone Service Circuit input line of answering the call is talked about the Service Circuit input machine talking and receiving circuit of answering the call.

2, a kind of words card public telephone set according to claim 1, it is characterized in that described words card, contain a n+2 jack and a mechanical notch, described n root fuse one end connects n jack respectively, the fuse other end be connected in parallel password resistance R X and a jack, another termination one jack of resistance R X.

3, a kind of words card public telephone set according to claim 1, it is characterized in that described called off hook signal treatment circuit, form by 450Hz frequency selection circuit, analog switch and delay circuit, the frequency-selector input machine talking and receiving circuit of answering the call, frequency-selector output connects the analog switch control end, analog switch one termination fixed potential, another termination delay circuit, delay circuit output connects described telephone expenses and nullifies testing circuit.

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