DE3120139C1 - Circuit arrangement for connecting an electronic ringing tone to a two-way telephone station - Google Patents

Abstract

The invention relates to a circuit arrangement for generating audible ringing signals at a two-way telephone station, a DC voltage being obtained from an applied ringing tone with which voltage a ringing tone circuit is controlled which in turn activates a piezo transducer. The object of the invention is to produce a respective individual ringing tone depending on the telephone line which is seized by an incoming call, only a single ringing-tone-generating switching means being intended to be used and the disconnection of the two telephone lines from one another having to be guaranteed in each station condition. The ringing tone characteristic is modified and a line-specific ringing tone is thus generated by different activation of the ringing tone circuit (TSK) depending on the telephone line (a1/b1, a2/b2) which is seized by an incoming call. Only a single ringing-tone-generating switching means (PW) is used in this case. The circuit (TSK) is activated by means of a DC voltage obtained from the AC ringing voltage by means of resistors (R2/R4, R12/R14) and rectifier elements (T1/T2, T3/T4) which enable partial voltages to be tapped in each case via a rectifier circuit (G1, G3). <IMAGE>

Description

The TSK ringing circuit works when a supply voltage is applied at its connections 1 (plus) and 2 (minus) and gives in regular sequence at its Terminal 5 opposite its terminal 2 positive current surges. These hold an excitation interval determined by the size of the at its terminals 3 and 4 connected resistors R 5 and R 6 is determined. This will make the Piezo transducer PW triggered to vibrate and emits acoustic tone signals, their sound characteristics through the size of the excitation interval and thus through the size of the resistors R 5 and R 6 is determined. With the resistor R 8 leaves adjust the volume of these ringer signals. Via connections 6 and 7 of the ringing circuit TSK and the resistors R 9 and R 10 and the capacitor C5 can basically also change the timbre of the acoustic ringer signals change.

Call on L 1 It is initially assumed that only the Telephone line L 1 enters an electrical ringer signal. The alternating ringing current flows from the wire a 1 via the normally closed contact of the non-actuated key H1, the capacitor C1, the rectifier circuit G1, the capacitor C2 and the resistor R 1 for Wire b 1. Between the plus and minus DC connections of the rectifier circuit G 1, a pulsating direct current flows through the Arei relatively high-value resistors R 2, R 3 and R 4, which are designed so that the potential at the tap between the Resistors R 2 and R 3 to the positive terminal of the rectifier circuit G 1 downstream PNP transistor T1 controls permeable and the potential at the tap between the resistors R 3 and R 4 to the negative terminal of the rectifier circuit G 1 downstream NPN transistor T2 is activated.

This is the positive or negative potential of a pulsating DC voltage across the transistors T1 and T2 and in the forward direction of the pulsating direct current switched on diodes D 1 and D 2 at the connections 1 and 2 of the ringing circuit TSK.

The two potentials are through the diodes D3 and D4 to the telephone line L2 blocked so that the positive potential does not pass through the resistor R 15 can reach the transistors T5 and T6 and these are therefore blocked.

The ringing circuit TSK gives a specific one from the connection 5 Excitation interval sustained current surge across the resistor R 7, the volume control variable resistor R 8 and the piezo transducer PW to connection 2, and the piezo transducer PW generates an acoustic ringing signal. The sound characteristics of the ringing signal is given by the sum of between terminals 3 and 4 of the ringing circuit TSK lying resistors R5 and R 6 are determined.

Call on L 2 It is now assumed that only over the telephone line L 2 an electrical ringing signal arrives, then the alternating ringing current flows from the wire a 2 via the normally closed contact of the non-actuated button H2, the capacitor C4, the rectifier circuit G3, the capacitor C3 and the resistor R 11 for Wire b 2. Between the DC connections plus and minus of the rectifier circuit G3 a pulsating direct current flows through the three relatively high-ohmic resistors R 12, R13 and R 14, which are designed so that the potential at the tap between the resistors R 12 and R 13 to the positive terminal of the rectifier circuit G3 downstream PNP transistor T3 controls permeable and the potential at the tap between the resistors R 13 and R14 to the negative terminal of the rectifier circuit G 3 downstream NPN transistor T4 controlled.

This is the positive or negative potential of a pulsating DC voltage across the transistors T3 and T4 and in the forward direction of the pulsating direct current switched on diodes D3 or D4 at the connections 1 and 2 of the ringing circuit TSK.

The two potentials are through the diodes D t and D2 to the telephone line L 1 blocked. The positive potential at the output of the PNP transistor T3 This time it reaches the bases of one transistor switch via the resistor R 15 forming anti-parallel connected NPN transistors T5 and T6, which are now turned on and short-circuit the resistor R 6. This lies between the connections 3 and 4 of the ringer circuit TSK only the resistor R 5. The ringer circuit TSK gives from connection point 5 in turn an a certain excitation interval lasting Current surge through the resistors R 7 and R 8 and the piezo transducer PW for connection 2 from, and the piezo transducer PW again generates an acoustic ringer signal. This has compared to the ringing signal generated when the telephone line L 1 is seized a different sound because the sound characteristics are determined by the between the terminals 3 and 4 of the Tonrufschaltkreises TSK lying resistor R 5 is determined alone Calls on L 1 and L 2 at the same time Hits over both telephone lines L1 and L2 at the same time an electrical ringer signal, then both sides (via T1 / T2 and T3 / T4) a pulsating DC voltage to the ringer circuit TSK delivered. Since, however, the potential for bridging over the telephone line L 2 of the resistor R 6 is supplied to the bases of the transistors T5 and T6, sounds only the acoustic ringing signal for the telephone line L 2. This has priority switched; because as long as there is always an electrical one on the telephone line L 2 Ringer signal arrives, this is independent of the arrival of an electrical one Ringing signal on the telephone line L 1 displayed first.

One would use the one used to turn on the transistors T5 and T6 Tap the potential between the transistor T1 and the diode D 1, then that would be Telephone line L t switched with priority. Will the over the phone line L 2 attached connection request z. B. accepted by lifting the handset, then the line section shown is via the hook switch, not shown separated, and it is thus canceled the control of the transistors T5 and T6. The acoustic ringing signal for the telephone line L 1 now sounds.

With the help of the switch on the respective telephone line L 1 or L2 operated normally open contacts of buttons H 1 or H2 is the incoming one electrical ringer signal optically displayed electrical ringer signal rectified by the rectifier circuit G2 and the optical display means A 1 supplied. In the case of the telephone line L 2, this will be electrical ringer signal rectified by the rectifier circuit G 4 and the optical display means A 2 supplied.

In the brokering mode, the visual display means including the rectifier circuit as Terminating resistor (holding resistor) for the line on hold (connection).

From the above it can be seen that with the aid of the invention is possible in a simple manner with only a single ringing element each telephone line connected to a two-way telephone station has one to assign individual ringtones and at any time the separation of the telephone lines to ensure.

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Claims (2)

Claims: 1. Circuit arrangement for generating acoustic Ringing signals by means of a rectified ringing alternating voltage of the incoming Ringing signal fed ringer circuit and one stimulated by this intermittently piezoelectric transducer in telephone systems with two special connecting lines reachable telephone stations, d u r c h e k e n n -z e i c h n e t that each connection line (L 1 resp. L2) a capacitive (by means of C1 and C2 or C3 and C4) sealed off Rectifier circuit (G 1 resp. G3), whose DC voltage connections (+ and -) have a due to the DC voltage occurring across them (partial voltage at R 2 and R 4 or on R 12 and R 14) controllable directional guide (Tl and T2 or; T3 and T4) to the two supply connections (1 and 2) of the ringing circuit (TSK) are connected, and that with one DC voltage connection (+) of the a rectifier circuit (G 3) connected directional conductor (T3) on the one hand via a in the direction of the supply current permeable further directional conductor (D 3) with the a supply connection (1) of the ringer circuit (TSK) and on the other hand with a switch that changes the excitation interval of the ringer circuit (T.SK) (T5 and T6) is connected. 2. Circuit arrangement according to claim 1, characterized in that that between the a-I> wire of each telephone line (L 1, L2) a further Rectifier circuit (G2, G4) is arranged, the DC side with a optical display element (A 1, A2) connected to display an existing ringer is. The invention relates to a circuit arrangement for generating acoustic ringing signals by means of a rectified alternating ringing voltage the incoming ringing signal fed ringer circuit and one of this intermittently excited piezoelectric transducers in telephone systems with over two separate connection lines accessible telephone stations. At such a two-way telephone station it is for incoming people Conversations, it is useful to know which ones are being used before picking up the handset of the two telephone lines the call is present. For this reason, a known circuit arrangement (basics of TN switching technology, Frankfurt, 1964, page 134, two-way apparatus) for distinguishing calls for one Telephone path an alarm clock and provided for the other telephone path a buzzing. With this solution there is a different one for each telephone path acoustic signal so that the subscriber located at the two-way telephone station can see from this which telephone path the call is pending. However, this type of solution has the disadvantage that the alarm clock as an acoustic Signal element is relatively expensive and that, in some circumstances, an additional one Additional box must be used. In addition, two sound-producing elements are necessary. It is also known (DE-OS 2539415) that one in the ringing circuit each of the two telephone paths in the idle state and in the waiting state a series connection one of them supplies a light-emitting diode with a direct current obtained from the ringing current Rectifier bridge, a capacitor and a snare is arranged. These Circuit arrangement, however, also has the disadvantage that two elements act as a tone generator are necessary when the necessary, complete separation of both telephone lines should be guaranteed in every condition. The object of the invention is now to consist in a circuit arrangement for connecting an electronic ringer to one of the above-mentioned station circuits to find that makes it possible to use only one ringing element assign each telephone line its own ringing tone, with the separation of the two telephone lines at all times and in every state of the station is. This is achieved according to the circuit arrangement according to the invention achieves that each connection line is a capacitively sealed rectifier circuit has, whose DC voltage connections each have one through the occurring at them Direct voltage through controllable directional conductor with the two supply connections of the ringer circuit are connected, and that of the one DC voltage connection the directional conductor connected to a rectifier circuit on the one hand via an in Direction of the supply current permeable further directional guide with the one Supply connection of the ringer circuit and on the other hand with one the excitation interval the ringer circuit changing switch is connected. The advantage of the circuit arrangement according to the invention is therein too see that depending on the incoming busy telephone line a different control of the ringer circuit and thus a different ringer output by the piezo transducer he follows. If the ringing tone is present on both telephone lines at the same time one telephone line is preferred and the individual call is preferred for the second telephone line becomes audible only after accepting the connection over the first telephone line. Another advantageous embodiment of the invention consists in that between the a-b wire of each telephone line a further rectifier circuit is arranged, the DC side with an optical display element for display an existing tone call is connected. This has the particular advantage that at the same time pending ringing tone over both telephone lines a ringing tone acoustically and both Tone calls are visually recognizable. The invention will now be illustrated with reference to the drawing Embodiment explained in more detail. The arrangement shown consists essentially of the two Telephone lines L 1 and L 2 with the wires a llb 1 and a 2 / b 2, the rectifier circuits G 1 to G4, the ringer circuit TSK (IC assembly), the piezo transducer PW the display means A 1 and A 2, the transistors T1 to T6, the keys Hl and H2, the diodes D 1 to D 4, resistors R 1 to R 15 and capacitors C1 to C5.