CN2170611Y - Party-line telephone - Google Patents

Abstract

The utility model relates to a party-line telephone which utilizes unidirectional pulse signals to ring by number. Both ends of a ringing circuit of the telephone are connected in parallel with a triode switching circuit which is switched off and on accordingly following the electric charge and discharge of a capacitor in series connection in the ringing circuit so that the ringing efficiency of unidirectional pulse signals is enhanced. The circuits of the utility model are disclosed in the specification.

Description

Party-line telephone

This is a kind of telephone line multiplexing equipment.

Make the ring of party-line check mark, more easy method is exactly that ringing signal is become two kinds of different pulse signals of polarity after rectification, and two users breathe out respectively.What " telecommunication technology " 1988 the 6th phases the 14th page " the contrary sign party-line of simple and easy practicality " were introduced is exactly this scheme (seeing accompanying drawing 1), its operation principle is: it is Interface Terminal a1---b1 and a2---b2 that is connected to respectively after first plane No. line and second plane No. line respectively lead through two groups of rectifier diodes among Fig. 1 that two subscriber's lines of switch connect the money terminal, like this, No. two line is sent to subscriber's line Xa---and the ringing signal of Xb all becomes the unidirectional pulse signal, feed polarity is: a1, a2 are for just, and b1, b2 are for negative.As calling party a1---when b1 was the first machine as called reception ringing signal, ringing signal was fed to circuit Xa---Xb through change over switch K1, K2, and feed polarity is Xa for just, and Xb is for negative.Simultaneously exchange interface terminal C1 be ground, with+12V is the relay J a adhesive of power supply, and control contact K3 connects, and K4 disconnects, and is that the current supply circuit of the relay J b of power supply is cut off with-12V, and assurance K1, K2 reliably connect.As calling party a2-b2 when being the second machine as called reception ringing signal, exchange interface terminal C2 is ground, with-12V is the relay J b adhesive of power supply, control contact K1, K2, K5, K6 conversion, bell signal is fed to circuit Xa-Xb through K1, K2, and feed polarity is that Xa is negative, and Xb is for just.As seen, collinear last two users its feed polarity when called has nothing in common with each other, and calls out that user with difference.It more than is the operation principle of switch end (user interface).The operation principle of user side is: when first machine during as called reception ringing signal, unidirectional pulse signal polarity on the circuit is Xa for just, Xb is for negative, be loaded on the polarity identification diode D conducting in the phone first casing, (the polarity identification diode polarity in the phone second is opposite with the phone first, end this moment), capacitor C charging, polarized bell vibrates once.At inter-train pause, resistance R provides discharge loop for C, and polarized bell vibrates once more, so repeatedly, and continuous ringing.When phone second during as called reception ringing signal, the feed polarity on the circuit is with preceding opposite, and promptly Xa is for negative, and Xb is for just, and the first machine ends, the conducting of second machine, and operation principle is with aforementioned.

There is following shortcoming in such scheme: on the one hand, vibrate repeatedly for making polarized bell, the discharge loop of resistance R as capacitor C must be set; On the other hand, R can cause shunting and dividing potential drop attenuation to ringing signal respectively again when charging and discharge.For reducing the shunting attenuation, require the resistance of R to be the bigger the better; And, require the resistance of R the smaller the better again in order to reduce the dividing potential drop attenuation.Obviously, because R can only take into account charging and a definite value is chosen in discharge, thereby reduced ring efficient.

The purpose of this utility model is to make resistance R present high value when charging, presents low resistance when discharge, to improve ring efficient.

The purpose of this utility model is to realize (referring to accompanying drawing 2) like this: at the polarized bell that is in series with capacitor or electronic bell circuit two ends switching circuit K in parallel, to replace the resistance R in the former scheme.When pulse signal arrival capacitor C charged, K disconnected, and is equivalent to resistance R and is high value; The K closure is equivalent to R and is low resistance when the pulse signal clearance C is discharged.Just, K correspondingly disconnects connection repeatedly with charging repeatedly, the discharge of C.Accompanying drawing 3 is a kind of embodiment.The circuit unit that input terminal Xa, the Xb that connects external circuit and the lead-out terminal a, the b that are connected ringing circuit are comprised, be to be the switching circuit of core with transistor BG, the collector electrode of BG is electrically connected with input terminal Xa and lead-out terminal a, base stage is electrically connected with input terminal Xb, and emitter is electrically connected with lead-out terminal b.Be connected to biasing resistance R between the base stage of BG and the collector electrode, be connected to semiconductor diode D ' between base stage and the emitter.Semiconductor diode D is connected on the input terminal with identification feed polarity.Xa, Xb are the outside line input terminal, and a, b are electrically connected with polarized bell that is in series with capacitor C or electronic bell, and its operation principle is (referring to an accompanying drawing 3); The pulse signal of sending here as Xa-Xb is that Xa is positive Xb when negative, and triode BG is anti-, and diode D ' provides path for signal partially by being high value, capacitor C charging, and polarized bell vibrates once.This moment, biasing resistance R was owing to be high value, can reduce attenuation in parallel; Inter-train pause, the capacitor C that has charged is equivalent to power supply, is partially anti-for isolating diode D ', is that positively biased makes its conducting for triode BG, and capacitor C provides discharge loop, and polarized bell is vibrated once more.BG is low resistance when conducting, can reduce the series connection attenuation.Four terminal Xa, Xb, a, the circuit that b comprised is called the phone interface, the phone interface is placed in the ordinary telephone set casing as shown in Figure 4, its input is connected with the input terminal Xb of ringing signal and the normally-closed contact of the hook state of switch hook CH, like this, the collector electrode of triode BG is actually order with input terminal Xa and is electrically connected through diode D and switch hook CH, with lead-out terminal a then is directly to be electrically connected, its output is electrically connected with the electric bell circuit that is in series with capacitor C, the speaking circuit part normally opened contact during with the CH on-hook is electrically connected, be exactly a complete Multiparty telephone, it can with the supporting use of the user interface of former scheme.

Claims (2)

1, a kind of Multiparty telephone, comprising casing, conversation part, feed polarity identification diode [D], be in series with the polarized bell or the electronic bell of capacitor [C], it is characterized in that: be in series with the polarized bell of capacitor [C] or electronic bell two ends and be parallel with the corresponding switching circuit that disconnects repeatedly, connects that charges repeatedly, discharges with capacitor [C].

2, Multiparty telephone as claimed in claim 1, it is characterized in that: switching circuit is a core with transistor ［ BG ］, the collector electrode of ［ BG ］ is electrically connected through diode ［ D ］ and switch hook ［ CH ］ with input terminal Xa order, a directly is electrically connected with lead-out terminal, emitter is electrically connected with lead-out terminal ［ b ］, base stage is electrically connected with input terminal ［ Xb ］, is connected to semiconductor diode ［ D ' ］ between base stage and the emitter.

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