CN1230841A

CN1230841A - Ringing-signal feeding method for telephone exchange

Info

Publication number: CN1230841A
Application number: CN 98106774
Authority: CN
Inventors: 孙连仲
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-29
Filing date: 1998-03-29
Publication date: 1999-10-06

Abstract

A ringing source is connected to the other line, and the ringing voltage and the superposed DC voltage are distributed reasonably on the two lines with the sum being equal to 60-90V. Using the method of the present invention makes the maximum intrusion voltage to exchange below 130V and this can reduce the power of the exchange to 1/4 of available value and protect exchange through reducing the possibility of voltage puncture and power burning of the electronic components in exchange. The present invention is suitable for any exchanges of different system.

Description

Ringing-signal feeding method for telephone exchange

The present invention relates to the telephone exchange in the communication equipment.

Ringing signal in the telephone exchange is high voltage, the low frequency AC signal that is sent to called subscriber's phone (terminal equipment) by switch.Its effect is to make the ring of called subscriber's phone, and advise called subscriber has the people to call out at this moment, and called subscriber's off-hook can begin conversation.In order to make the phone ringing tone that enough loudness be arranged, require the voltage of ringing signal necessary enough high.For this reason, Ministry of Posts and Telecommunications's standard code, the output voltage in ringing signal source should be within 60 volts to 90 volts scopes, and frequency is 25 ± 3 hertz, and waveform is sinusoidal wave.Whether off-hook is replied during ring for the ease of detecting the user, and a direct current negative voltage is advanced in stack again in this ringing signal, and this negative DC voltage generally is the supply power voltage of switch, and scope is between-40 volts to-57 volts (over the ground).These two kinds of voltages are superimposed, and its highest negative peak voltage reaches 184.3 volts of (90 * 1.414+57) volts.Existing technology is: when switch during to the substation ringing-signal feeding, only give this bell signal to user's a line, another line b line of user is through protective resistance ground connection.So just caused during ringing-signal feeding, user's a line-to-earth voltage is very high, brings difficulty for the protection of switch.The protection of switch generally has two-stage, and the first order is placed on and is called once protection on the main frame; The second level is placed on the exchanger user plate, is called second protection.Once the sketch of protection and existing ringing-signal feeding method as shown in Figure 1; the dotted line right side is that switch send bell method sketch among the figure, and RS is the ringing-current source, and R1, R2 send the bell protective resistance in user's plate; K1, K2 are conversation and ring changeover contact, and E is an exchanger power.Dotted line left side is for once protecting sketch among the figure, and wherein F1, F2 are the overvoltage protection element, and its effect is the voltage that clamp enters switch, prevents that switch from burning because of forceful electric power or thunder and lightning intrusion, and a, b two lines connect substation through cable.At present, F1, F2 mostly adopt gas discharge tube (also have adopt solid discharging tube but principle is identical), just protect effect, its discharge voltage is low more, and is just strong more to the protective effect of switch.; under existing single line ringing-signal feeding method; limited the reduction of discharge tube F1 discharge voltage, required the minimum discharge voltage (referring to absolute value) of F1 must be greater than the peak value (absolute value) of ringing-current voltage and the stack of feed voltage maximum (absolute value), promptly greater than 184.3 volts.Otherwise when ringing-signal feeding, can cause that discharge tube F1 discharge goes into ground with the ringing-current bypass, cause not jingle bell of called subscriber's phone, can't finish conversation.Send under the bell method requirement to F2 just much lower this, no matter when ring, still when conversation, b line-to-earth voltage (absolute value) all is no more than 30 volts.For the ease of safeguarding and produce, discharge tube F1 and F2 generally select for use identical parameters, discharge voltage greater than 190 volts.Be subjected to the restriction of manufacturing process in addition, the error of marked voltage of discharge tube about 15%, so the Ministry of Posts and Telecommunications's standard code discharge voltage of discharge tube minimum be 190 volts, be up to 260 volts.This shows, under this single line ringing-signal feeding method, when forceful electric power or thunder and lightning are invaded by telephone wire, have high voltage and enter switch.And stored-program control exchange is made up of integrated circuit and electronic component, though the second protection device is arranged, is still burnt unavoidably.The important drawback of Here it is single line ringing-signal feeding.

The objective of the invention is by providing a kind of telephone exchange new ringing-signal feeding method, thereby reduce the discharge voltage of F1, F2 in the once protection significantly, stop of the infringement of external high voltage, further strengthen protection switch to telephone exchange.

The present invention is achieved in that the single line ringing-signal feeding method of correcting one's mistakes is that two-wire send simultaneously, ringing-current voltage and the direct voltage that superposeed are considered in the lump and reasonably is distributed on two lines of a, b.Preferred plan is that the b line also inserts a ringing-current source, b line ringing-current source output voltage and a line ringing-current source output voltage sum equal the 60-90 volt, two ringing-current source frequencies are identical, phase place is opposite, output to the ringing-current voltage amplitude stack of a, b line-to-line, guarantee that user's ring is not affected.After changing like this, both guaranteed normally sending of bell signal, and made when ringing-signal feeding a, b two line-to-earth voltages (referring to absolute value) equal substantially simultaneously again.Operation principle of the present invention is compared with accompanying drawing 1 as shown in Figure 2, increases a ringing-current source at the b line and is referred to as RS2, and ringing-current source RS originally is referred to as RS1 and reduces the voltage output amplitude, and other are all with accompanying drawing 1.In accompanying drawing 2, RS1 is that a line ringing-current source, RS2 are b line ringing-current source (RS1, RS2 also can be the two-way output of same signal source), and send ringing-current to a, b two lines simultaneously respectively.The RS1 into direct voltage that superposes, ringing-current source RS2 characteristic is unaffected during user answer, the signalling frequency that RS1, RS2 sent is identical, phase place is opposite, the output stack, meet Ministry of Posts and Telecommunications's standard-required, thereby guarantee when the ringing-current voltage that obtains at the substation end is with the single line ringing-signal feeding identically, do not influence the phone normal ringer and reply.As shown in Figure 2, as if 90 volts of ringing-current voltages, and RS1 stack negative dc voltage, then RS1 should send the highest ringing-current voltage that is no more than 25 volts of effective value, and RS2 should send the highest ringing-current voltage that is no more than 65 volts of effective value.Like this, when ringing-signal feeding a line and b line over the ground ceiling voltage (absolute value) all be no more than 93 volts, discharge tube F1 in protected location and F2 all can select 95 volts-130 volts for use, reduce half than original 190-260 volt.Also direct voltage (reply detect with) separately can be superimposed upon RS1; on two ringing-current sources of RS2; as shown in Figure 4; 40 volts of cut-off stream voltages; 90 volts of ringing-current voltages; negative 20 volts of the stackable direct voltage of ringing-current source RS1; send the highest ringing-current voltage that is no more than 45 volts of effective value; then superpose 20 volts of direct current positive pressures of ringing-current source RS2; send the highest ringing-current voltage that is no more than 45 volts of effective value; in the case; when ringing-signal feeding a line and b line over the ground ceiling voltage (absolute value) all be no more than 85 volts, once discharge tube F1 in the protection and F2 all can select 85 volts-125 volts for use, than original 190-260 lie prostrate reduction half.

External voltage has two kinds of situations nothing but to the destruction of telephone exchange, and the one, overtension, the breakdown damage of individual metablocks device, the 2nd, the power that is applied on certain components and parts is excessive, makes the element scaling loss.According to the bell method of sending of the present invention, the highest over the ground negative peak voltage of a line is no more than 93 volts when sending bell; B line peak-peak voltage over the ground also is no more than 93 volts.Like this, the discharge voltage that is added in overvoltage protection element discharge tube F1, F2 on a, the b line is minimum can get 95 volts, the highlyest gets 130 volts.Under the same conditions, when forceful electric power rides on the subscribers feeder, adopt the present invention, the ceiling voltage of invading switch is no more than 130 volts, has reduced half than original 260 volts.Electronic component in the switch is because overtension and breakdown possibility significantly reduces.Because voltage is reduced to originally 1/2, and it is original 1/4 that power is then reduced to, electronic component is also reduced by the possibility of scaling loss significantly because of power is excessive again.Can affirm that thus telephone exchange has obtained better protect.Can be country and save substantial contribution, obvious social benefit.The present invention is applicable to the switch of any standard, and the equipment change is little, and investment is few, implements easily.After the invention process,, subsets, telephone line all there is not specific (special) requirements to the not change of other performance of switch.

Accompanying drawing 1 is existing ringing-signal feeding method sketch;

Accompanying drawing 2 is ringing-signal feeding method sketches of the present invention;

Accompanying drawing 3 is to implement side one ringing-signal feeding method sketch;

Accompanying drawing 4 is embodiment two ringing-signal feeding method sketches.

Embodiment one:

The present invention is applied on the homemade HJDO4 type switch, and as shown in Figure 3, the effect of the R1 among the figure, R2, F1, F2, K1, K2 and E only needs the ringing-current transformer T that line module is original to change two groups of outputs into by one group of output and gets final product with accompanying drawing 1.1,2 ends of T are that input is received on the ringing current generator.Wherein 3,4 ends output ringing-current is about 20 volts, about 60 volts of 5,6 ends output ringing-currents.With 4 terminate switched machine negative voltages (40-57 volt); the original ringing wire of 3 terminations (being the R1 lower end); 5 end ground connection, 6 termination user circuit board b lines are sent bell protective resistance R2 lower end (this resistance lower end is ground connection in user circuit board originally, earth terminal be disconnected drawing connecing 6 ends).Because of 3,6 ends are the different name end, the output voltage stack., measure with digital oscilloscope to user's ringing-signal feeding with the method, a line peak value over the ground is no more than negative 90 volts, and b line-to-earth voltage peak value also is no more than 90 volts.User's ring, reply and converse all normal.

Embodiment two:

The present invention is applied on the import switch NEAX61.As shown in Figure 4, the effect of F1, F2 is with accompanying drawing 1 in accompanying drawing 4, and S representative of consumer circuit board, CRO, CROG are user circuit board bell signal input.RS1 is an a line ringing-current output device, RS2 is a b line ringing-current output device, frequency is identical in order to obtain, phase place opposite, the ringing-current voltage of amplitude stack, the input signal of RS1, RS2 is all taken from 45 volts of 1, the 2 ends output ringing-current voltages of same signal generation apparatus SY (output frequency of SY is that 25 hertz of sine waves, deviations are no more than 3 hertz) RS1, and bears 20 volts from the 2 ends direct voltage E1 that superposes over the ground; 45 volts of 3,4 ends of RS2 output ringing-current voltages, 4 ends positive 20 volts of the direct voltage E2 that superposes over the ground.Like this, 90 volts ringing-current voltage output is arranged between 3 ends of 1 end of RS1 and RS2, and 40 volts of the direct voltages of having superposeed into.Concrete wiring only needs ringing-current line CRO, CROG are disconnected, the CRO end of the 1 termination S of RS1, and the CROG end of the 3 termination S of RS2 gets final product.By sending ringing-current method ringing-signal feeding shown in the accompanying drawing 4, with digital oscilloscope record a line over the ground crest voltage be no more than negative 85 volts, b line crest voltage over the ground is no more than 85 volts, and, the substation ring, reply and converse all well, other performances are less than change.

Claims

1, ringing-signal feeding method for telephone exchange, the a line connects a ringing-current source and stack advances to reply the detection direct voltage, it is characterized in that the b line also inserts a ringing-current source, b line ringing-current source is identical with a line ringing-current source frequency, phase place is opposite, the output stack, and b line ringing-current source output voltage and a line ringing-current source output voltage sum equal the 60-90 volt.

2,, it is characterized in that separately being superimposed upon on two ringing-current sources with replying the detection direct voltage according to the said ringing-signal feeding method for telephone exchange of claim 1.