JPS6298947A - Telephone set - Google Patents

Abstract

PURPOSE:To improve the operability by providing a rectifier circuit, an impedance circuit, a discharge circuit and an oscillator, ringing telephone sets connected in parallel simultaneously at the reception of a call signal and stopping the ringing at the reception of a pulse dial. CONSTITUTION:At the rising of a power supply VCC, the impedance of a discharge circuit 23 provided to the input section of an IC is kept low initially to attain the state that an electric charge stored in a capacitor C2 is discharged to a ground potential easily. Then a signal is fed intermittently to a Tip and a Ring terminal, the charging of the capacitor C2 is progressed and when the power voltage VCC reaches a prescribed level, the impedance of the discharge circuit 23 is switched to a high state, the discharge of the electric charge stored in the capacitor C2 is suppressed to rise the power voltage VCC rapidly. When the VCC reaches a sufficiently high potential further, the discharge circuit is brought automatically to the non-operating state, an oscillation circuit 23 and a logic circuit 24 are activated to drive a tone ringer. Thus, in dialing one telephone set of the telephone sets connected in parallel, the ringing of the other telephone set is prevented completely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a telephone equipped with a tone ringer.

[Background technology]

“Integrated Circuit Application Handbook J (first edition published June 30, 1981, Asakura Shoten Co., Ltd., p.599-p.60)
No. 0) describes that intensive research is being conducted on the integration of telephone circuits into semiconductor integrated circuits.

The inventors of the present application have also conducted various technical studies regarding telephones in view of the above-mentioned technical trends.

As a result, they found that when multiple telephones were used in parallel, dialing on one telephone caused resonance in the other telephones. In particular, in a telephone equipped with a telephone IC' commonly called a tone ringer, the ringing sound when an incoming call is received from the outside and the resonance sound caused by dialing on one side of the telephone are almost the same, so it is extremely difficult to use. It turned out that it was difficult to distinguish. The above phenomenon is particularly noticeable in telephones using IC, and the reason for this has been clarified by the inventor as follows.

Hereinafter, with reference to FIGS. 5 to 7, we will discuss the occurrence of the resonance phenomenon, etc. 8 will be explained in sequence.

The telephone exchange shown in Figure 5
hange) 1 to 2 telephones 11, 11'
are connected in parallel through all the Tip and Ring terminals 2 and 3.

Since the two telephones 11 and 11' have a [1-circuit configuration, only the telephone 11 will be explained, and the explanation of the other telephone 11' will be omitted by adding a dash to the same reference numeral.

SWl and SW2 are hook switches, and when the hook is on, in other words, when waiting for a call, they are in the switching state shown in the figure, and when the handset is lifted, they are switched to the state shown by the dotted line.

On the other hand, the calling signal P from the exchange 1 is a 16Hz signal as shown in FIG.
After the remainder, a 16Hz signal is generated again for 1 second, and this is sent to the tone ringer as a calling signal P.
applied to circuit 13. Then, the tone ringer circuits 13 and 13 in the telephone set 11 and 11 operate at the same time, producing exactly the same ring tone at the same time, and when the receiver 12 is lifted, the switches SW1 and SW2 change to the switching state as shown by the dotted line, and the dialer (Pulse Dialer)
14. Speech Network (5peech Net
work) 15 is operated and a call is made.

Next, the circuit operation during transmission will be described.

When you lift the handset 12 of the telephone 11, the switch SW
I, SW2 are switched as shown by the dotted line, and the switches SW,
', SW2' are the exact dimensions of the solid line.

Also, Pulse Dialer
14 consists of a dial (which may be a rotary type or a set of pushers), a memory for storing dialed numbers, and a pulse generator for generating pulses in accordance with the information stored in the memory. And dialer-1
When, for example, 031 is dialed by the operation in step 4, 72 dial pulses with a waveform as shown in FIG.
3 will also be sent.

The tone ringer 13' is driven by the pulses generated by the pulse dialer 14, causing resonance.

In other words, the IC tone ringer circuit 13.13
' is smoothed after full-wave rectifying the signal at the Tip-Ring terminal, and while this rectified and smoothed voltage is supplied, an oscillation circuit is driven to obtain an oscillation sound (ringing tone). However, the quality of the oscillation sound is not different between the calling signal shown in Figure 6 and the 72 dial pals shown in Figure 7.The difference between the two is the interval between signal generation, but one
sec, while the other one is, for example, 0.8 sec.
(It differs depending on the dialer), so the difference in audibility is not clear, and the above problem appears.

By the way, if you have a phone with a tone ringer,
General standards include the following conditions: ``When the pulses generated by the pulse dialer 14 are supplied, there should be no resonance at an input pressure of 60V or less, and when the ring voltage is input from the exchange, the ringing should start at 45V or less.'' Therefore, since there is a time difference as mentioned above between when the pulse dialer is supplied and when the ring voltage is input, the inventor of the present invention proposes to appropriately select the input impedance and detect the energy based on the above time difference, in other words, to detect the entire difference between the two. They realized that it is possible to completely prevent resonance, and came to propose the present invention.

[Object of the Invention] The object of the present invention is to provide a tone ringer that is integrated into a semiconductor circuit.
To provide a telephone having a circuit which can clearly receive ringing tones from the outside and can eliminate resonance generated when dialing in a series-connected III telephone.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

Representative examples of the invention disclosed in this application are briefly described below.

That is, after the rectifier circuit that rectifies the call signal and pulse dialer supplied from the 'rtp and R1ng terminals, there is a power supply stabilization circuit that changes impedance according to the level of each signal and stabilizes the rectified output. The capacitor 02 forming a part of the power supply stabilizing circuit is charged with the rectified output which becomes the power supply Vcc of the tone dialer circuit, and is started up with a certain time constant. At the rise of the power supply VCC, the impedance of the discharge circuit provided at the input section of the IC is kept low initially (that is, when the power supply voltage VCC is less than a predetermined level), and the charge stored in the capacitor 〇, for example, is kept low. Despite being in this state,
A signal is intermittently supplied to the Tip and R1ng terminals, and as a result, the charging of the capacitor 〇 progresses, and when the power supply voltage VCC reaches a predetermined level, the impedance of the discharge circuit is switched to a high state, and the impedance stored in the capacitor 02 is switched to a high state. Discharge of charges is suppressed, and the power supply voltage Vccf is allowed to rise rapidly. Furthermore, when VCC reaches a sufficiently high potential, the discharge circuit is automatically rendered inactive, and the oscillation circuit 23. The tone ringer is driven by operating the logic circuit 24 and the like. By providing the above functions, when the dial 7゛ pulse from one of the telephones connected in parallel is input to the other telephone, the energy of the dial pulse is higher than that of the New Year's call. , is extremely small, so the capacitor 02 is not charged due to the action of the discharge circuit, and the VC
C does not rise to a predetermined value of 1, so that the tone ringer can be deactivated, ie, the tone ringer is activated only when intermittent ringing pulses are applied from the central office to Tip, R3ng.

In this way, it is possible to achieve the object of the present invention, which is to completely prevent resonance in one telephone when dialing one in parallel connected telephones.

〔Example〕

Next, an embodiment of a telephone to which the present invention is applied will be described with reference to FIGS. 1 to 4.

Furthermore, reference should also be made to FIGS. 6 and 7, which illustrate the causes of resonance. The feature of this embodiment is that, as mentioned above, attention is paid to the magnitude relationship between the energy of the external calling signal and the internal dial pulse, and the small energy of the dial pulse does not sufficiently raise the power supply Vcc. It is to make it.

The input impedance seen from the Tip and Ping terminals is
Although v@ can be adjusted by capacitor C3 and resistor R2,
For these values, it is better to adjust the impedance of the tone ringer in another circuit. However, this is not the case when the resistor R+ff1 is formed inside the IC.

The impedance of the tone ringer circuit seen from the rectifier circuit 21 can be set by the resistance component of the constant voltage circuit 22 (capacitor C2), but the impedance of the tone ringer circuit seen from the rectifier circuit 21 can be set by the resistance component of the constant voltage circuit 22. If the capacitance is made of gold, the cost will be high and the body S at the time of mounting will be large, so there is a limit to the capacitance value, and in this embodiment, the capacitance value is set to about 10 μF.

On the other hand, the resistance value of the resistance component RA consisting of the resistors R4 and R5 is determined in relation to the resistance R3 of the discharge circuit 23, and since the tone ringer circuit is integrated into an IC, a high resistance is not preferable.

By the way, in this example, the above resistance R2G k 30 K
I set it to about Ω, and tried setting the resistance component RA, which is a series combined resistance, to various resistance values. As a result, when the resistance component RA is set between approximately 500Ω and 6000Ω, an optimum impedance Kl is obtained that prevents resonance when the pulse dialer is operated manually and also causes a ringing state when a call signal is input.

Next, before explaining the tone ringer circuit, we will discuss changes in input impedance.

Resistance R^+Rto't? By setting as described above, the input impedance of the tone ringer circuit viewed from the output side of the rectifier circuit 21 changes as shown in FIG. 2 when a calling signal is supplied, and changes as shown in FIG. 3 when a pulse dial is supplied. .

First, let's talk about when a call signal is input. In this case, the sound must be generated at 45V or less.

It has been found that the input impedance that allows ringing can be obtained when the resistance RAe is set to approximately 500Ω or more, as shown in FIG.

On the other hand, when a pulse dialer is supplied, resonance must be prohibited at an input voltage of 60V or less.

When the resistance RAe was set to approximately 5,600 or less, an impedance satisfying all of the above conditions was obtained as shown in FIG.

Referring to Figures 2 and 3 above, the resistance R^ is 500
By setting the impedance between Ω and about 560Ω, ringing and resonance can be prevented by changing the impedance.

Note that since it is a series composite resistance of resistor RA11, resistor R4, and Rs, the resistance values of resistors R, , R, and R are each 1/2・R.
It may be taken as the resistance value of a.

When the input impedance of the tone ringer circuit changes as described above depending on the ringing signal and the pulse dialer, the rise change in the rectified output will differ depending on the two.

That is, a distinction is made between when a calling signal is input and when a pulse dialer is supplied, and the tone ringer circuit operates as described below in response to these.

First, the reception of a call signal supplied from the outside will be described.

At the time of reception, a reception signal as shown in FIG. 6 is supplied to the Pip and Ring terminals shown in FIG.

Then, it is rectified by a bridge circuit 21 composed of transistors Q1 to Q4.

Transistor Q, ~Qa+ Zener diode ZD
,~ZD6. The resistors R2 to (2) and the capacitor 02 operate as a power supply stabilizing circuit 22, changing the impedance as described above and also performing an overvoltage protection operation.

Next, the operation of the discharge circuit 23, which plays an important role in the present invention, will be explained. When a call signal is supplied to the Tip, ]ling terminal, and as a result, the capacitor 〇, is charged and VCC gradually rises, first the transistor QI
4. ) transistor Q+s+Q+.・Resistance R, ~R+
An initial current flows to the base of transistor Q+2 via tk. Then, the transistor Q12 operates in the on state, and the transistor Q, which constitutes the entire current mirror circuit,
An initial current flows through the transistor Qlt.
, resistor R2°, and becomes the base current of the transistor Qs+ via the resistors R2° and R2+.

Also, a current flows through the transistor Q+ok, and a current 1. , I, the sum of 1!1. The current is the transistor Qs,
Flows to ground via resistor R2z' (j. That is,
Initially at the rise of VCC, the current I,.

I2. Due to the flow of I, it is difficult for the capacitor C2 to become fully charged.

Next, charging of capacitor 02 progresses, and VCC rises (II + I,) (R + R22) ” VB E
The voltage of O31 is the transistor Q. When the voltage required to fully turn on is 3VF 10VBEQ30 or more, (VF
Forward voltage of u diodes D2, Ds, D4) Current flow.

The current of the sum of and I2 now flows through the diodes D, ~D,.

The current flows through transistor Q30k. That is, the discharge circuit 23 changes to a high impedance state. As a result, the charging of capacitor 〇 is promoted, and V
CCi becomes even higher in potential. (Finally, it rises to 36V.) VCC is the j10 direction voltage of diode D, and further ZDs
,ZD6 ,ZD,,Z,. , ) transistor Q+ 9
When the voltage level exceeds the sum of vF (approximately 31.6 V), this current path current T5 flows, and this current I causes the transistor Q+? + Q+s operates in the on state. Then, currents Is and I both flow through transistor Q+i.
k will flow, resulting in Q+2. Qso is turned off. On the other hand, the output current of transistor QCs is supplied to the emitter of transistor Q2Q, and the output current of transistor Q+a is supplied to transistor Q, which constitutes the output circuit.
26,, O26r, O28, etc. are supplied through the connections shown in the figure.

Since the pace current is supplied to the transistor Qzo by the current 1°, the transistor Q20 r Qh+ is sequentially turned on, and the line! , the T source voltage vB appears. Then transistor Q2! r Power is supplied to the oscillation circuit (O8C section) 23 through Q23.
, a frequency signal fO according to the time constant of the capacitor Ctt is supplied to the logic circuit 24.

In addition, Zener diode ZD, ) transistor Qt4+
Power is supplied to the logic circuit 24 through a constant current circuit composed of resistors R, . . . R8. logic circuit 24
Is it the tone? The transistor Qts is driven by the output signal VO, and the output circuit composed of the transistors Qza+Qz transistor Qta+Qzo is operated to obtain the output signal Voot.

Note that a piezoelectric speaker, a magnetic speaker, or the like is connected to the output capacitor C6, and continues to sound in accordance with the time width of the calling signal.

Next, the operation of the circuit will be described when a dial pulse is supplied from one of the telephones in a parallel relationship to the other telephone.

In this case, the diode bridge 21 is supplied with the dial pulse described in connection with FIG. However, the dial pulse occurs only when the dial is rotating, and its total energy is small, so the capacitor C'+ cannot be sufficiently charged, and the power supply voltage is limited to each of the transistors QrysQ+a, as shown by the dotted line in Figure 4. It does not rise to the voltage level of the sum of the pace emitter voltage vBE, the j1 direction voltage of diode D, and further to diode ZD. To put it simply, the impedance of the power supply becomes low at startup, and if the power supply voltage does not reach a high level, high energy output cannot be obtained. Then, since the rectified voltage does not rise to a predetermined level, the above-mentioned transistor Qty+Q+a cannot be driven to the on state. Therefore, transistor Q, due to the output current of transistor Q+s. ,Q! + is not driven and no power supply voltage appears on line 11. Oscillation circuit 2
3. Both logic circuits 24 do not operate, and the output voltage Vo
Also, since the output current of the transistor Q+s is not supplied to the output circuit, no oscillation occurs from the speaker.

As described above, the tone ringer circuit to which the present invention is applied generates sound in response to a ringing signal from the outside, and does not sense a dial pulse signal from within.

Furthermore, the number of diodes D2 to D4 that convert changes in power supply voltage to changes in current is not limited to three, and may be set to any number.

[Application field]

In the above description, the invention made by the present inventor has mainly been described with respect to a tone ringer, which is the field of application behind the invention, but the invention is not limited thereto.

For example, it can be used for a telephone set C, an intercom, etc.

〔effect〕

(1)' Convert the power supply voltage obtained by rectifying the received signal that becomes the ring tone and the dial pulse signal from the inside into a binary voltage level by a power supply stabilization circuit and a discharge circuit having the desired input impedance, Since the oscillation circuit that obtains the audio signal is inactive when the rectified output is below a predetermined level, no sound is generated by dial operation except when receiving a reception signal that becomes a ring tone, and the ring tone from the outside is not generated. The effect is that the dial pulse can be clearly distinguished from the internal dial pulse.

(2) When converting the tone ringer circuit into an IC, the input impedance can be set to the desired value in conjunction with the resistance value setting of the discharge circuit, so there is no need to adjust external components, and the mounting This has the effect of improving work efficiency.

Although the invention made by the present inventor has been specifically explained above based on examples, it goes without saying that the present invention is not limited to the practical examples described above, and that various changes can be made without departing from the gist thereof. Nor.

For example, the input impedance of the tone ringer circuit can be set to a desired value by capacitor C2 and resistor R1 shown in FIG.

[Brief explanation of drawings]

Fig. 1 shows a circuit diagram showing an embodiment of a tone ringer circuit to which the present invention is applied, Fig. 2 shows a complete incoming call tone characteristic diagram of the tone ringer circuit when a ring tone is input, and Fig. 3 shows a pulse dialer supply. Figure 4 shows the input impedance characteristics of the tone ringer circuit at the time of operation, and Figure 4 shows the characteristics of the power supply voltage when fully rectified with the external calling signal and the internal dial pulse signal. A complete connection diagram of the electric machine is shown to explain the occurrence of the ringing phenomenon. Figure 6 shows the waveform diagram of the calling signal from the outside. Figure 7 shows the waveform of the dial pulse signal generated from the inside to the outside. Show the diagram. 1... Switchboard, "tt;1t'... Telephone, 12.
12'...Handset, 13.13'...Tone ringer circuit, 14°14...Dialer 115, 15'...
・Speech network, 21... Rectifier circuit, 22・
...Power supply stabilization circuit, 23...Oscillation circuit, 24...
Logic circuit, D, ~D4...diode, Q1~Q
! ,...Transistor, Il+2nd diagram C1A 3rd diagram/""J'V (61)
Figure 6 Figure 7

Claims (1)

[Claims] 1. (1) A rectifier circuit that rectifies a calling signal and a pulse dial signal supplied from another telephone connected in parallel; (2) A rectifier circuit provided before or after the rectifier circuit, and (3) an impedance circuit that changes characteristics in response to the voltage level of each signal and changes the level of the rectified output obtained from the rectifier circuit; (4) an oscillator that operates or deactivates in response to the binary voltage level and generates a signal sound when activated; A telephone set that is characterized in that telephones connected in parallel ring simultaneously when receiving a call signal, and stop ringing when receiving a pulse dial.