JPS61274463A - Interphone set with security function - Google Patents

Abstract

PURPOSE:To raise surely alarm without giving damage to the ear of the user and losing the talking when environmental abnormality takes place during talking by cutting of direct supply of an alarm signal to a talking system at talking and applying the alarm signal to the sounding part of the talking system while being attenuated. CONSTITUTION:A hook signal is fed to a door phone alarm control circuit 50 when a master interphone set 1 and a doorphone 40 are in talking and if an environmental abnormality takes place in this state, an AND circuit 51 in a doorphone alarm control circuit 50 is established by a logical '1' signal outputted by a surrounding detection circuit 27 and an analog switch 34 is turned off. Thus, even when an alarm tone signal is generated from a call/alarm tone generating circuit 30, it is not fed to the talking system. Then, the alarm tone signal is attenuated by a capacitor 60 and fed to a speaker 16 via one contact of a hook switch 15. Further, the alarm tone from the speaker 16 enters the talking system through a microphone 2 and is fed to the doorphone 40 as a talking back tone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an intercom device with a security function that includes a master intercom and a slave intercom.

[Technical background of the invention]

Recently, intercoms have become increasingly popular, allowing for mutual communication between the inside of a house and the front door, or between rooms, as well as security features that detect abnormalities in the environment and issue alarms.

An example of such an intercom device with a security function is shown in FIG.

In FIG. 3, 1 is a parent intercom, and 40 is a child intercom, so-called door phone. First, in the main intercom, reference numeral 2 denotes a microphone serving as a transmitter of a handset (not shown), and this microphone 2 is connected to a constant current circuit 5 via an amplifier 3 and a hook switch 4. The hook switch 4 opens as shown when the handset is placed down, and closes when the handset is lifted. The constant current circuit 5 supplies a predetermined current to the amplifier 3, captures changes in the output current of the amplifier 3 in response to input from the microphone 2, and outputs a voltage signal corresponding to the current change. Thus, the output of the constant current circuit 5 is supplied to the primary coil of the impedance matching transformer 10 through a DC cut capacitor 6, an analog switch 7, a power amplifier 8, and a DC cut capacitor 9 in series. . However, transformer 1o
The voltage generated in the secondary coil is supplied to a door phone 40, which will be described later. Furthermore, the voltage generated at the center tap of the transformer 10 is transmitted to the speaker 16, which is the sounding section, through the DC cut capacitor 11, the analog switch 12, the amplifier 13, the DC cut capacitor 14, and one contact of the hook switch 15. We are trying to supply it. Here, the other contact of the hook switch 15 is closed as shown in the figure when the handset is placed down, and one contact is closed when the handset is lifted. The speaker 16 serves as a receiver for a handset (not shown). In other words, a communication system is configured in which the microphone 2 and the speaker 16 perform mutual communication with the door phone 40.

In addition, the output current of the constant current circuit 5 is sent to the call switch button (push button automatic return type constant contact) 1 via the 7 switch 4.
7. Then, the voltage generated at the interconnection point between the constant current circuit 5 and the hook switch 4 is transferred to the call switching circuit 18.
The second input terminal of
is supplied to. The call switching circuit 18 has first and second
When a predetermined voltage is supplied to the first input terminal, the analog switch 7.12 is turned on, and a logic "1" signal is supplied to the power supply circuit 20 via the resistor 19. When the voltage supplied to the two input terminals is at zero level, the analog switch 7.12 is forcibly turned off. Therefore, for the first input terminal of the call switching circuit 18,
The voltage generated at one contact of the hook switch 15 is supplied.

The power supply circuit 20 includes resistors 21, 22 . A DC voltage ■ is applied between the collector and emitter of the NPN transistor 23, and the output of the call switching circuit 18 is applied between the base and emitter of the transistor 23 via a resistor 24 and 25. The base and emitter of 26 are connected in parallel to the resistor 21,
It operates when a logic "1" signal is input, and outputs the collector voltage of the transistor 26. Thus, the output voltage of the power supply circuit 20 is changed to the power amplifier 8.
and the secondary coil of the transformer 10 for operation.

On the other hand, 27 is an environment detection circuit in which a direct current voltage V is applied to a transfer contact 28 of an environment detector such as a flame sensor or a gas sensor through a resistor 29. When an abnormality occurs, the transfer contact 28 is turned on and the logic is activated. It emits a "1" signal. Thus, the output of the environment detection circuit 27 is supplied to the calling/alarm sound generation circuit 30. This ringing/alarm sound generation circuit 30 outputs a ringing sound signal when the voltage of input A or B is at zero level, but the environment detection circuit 2
When the output of 7 is logic 111 II, an alarm sound signal is output. However, the calling/alarm sound generation circuit 30
The output is supplied to the speaker 16 via the DC cut capacitor 31 and the other contact of the hook switch 15. Further, the output of the calling/alarm sound generating circuit 30 is supplied to the input terminal of the power amplifier 8 via the DC cut capacitor 31 and the analog switch 34. Furthermore, the output of the environment detection circuit 27 is supplied to the input end of the power supply circuit 20 and the door phone alarm control circuit 33 through a diode 32 in the forward direction. This door phone alarm control circuit 33 turns on the analog switch 34 if the output of the environment detection circuit 27 is logic "0°";
When the output of 7 becomes logic “1'', the analog switch 34
This is to turn off.

On the other hand, the door phone 40 includes a main control unit 41, a resistor 42, a call switch button (push button type automatic return type normally open contact) 43, a speaker 44, a microphone 45, etc.
It is connected to the telephone line. Note that the door phone 40 side line in the communication system of the main intercom 1 is connected to the calling/alarm sound generation circuit 30.

Therefore, when an abnormality occurs in the environment, the environment detection circuit 2
The output of 7 becomes logic "1". Then, the calling/alarm sound generation circuit 30 generates an alarm sound signal, and the power supply circuit 20 operates. Furthermore, the doorbell alarm control circuit 33 turns on the analog switch 34. The alarm signal generated by the ring/alarm signal generation circuit 3o is supplied to the speaker 16, and is also supplied from the analog switch 34 to the door phone 40 via the power amplifier 8 and transformer 10 of the communication system. In other words, parent intercom 1
An alarm sound is emitted from both the speaker 16 of the door phone 40 and the speaker 44 of the doorbell 40.

On the other hand, when the ring switch button 43 on the door phone 40 is pressed, the voltage at the input A of the ring/alarm sound generating circuit 3o in the master intercom 1 becomes zero level, and the ring/alarm sound generating circuit 30 emits a ring signal. This ringing tone signal is supplied to the spinica 16 via the other contact of the hook switch 15, so that the speaker 16 emits a ringing tone.

When the user picks up the handset of the main intercom 1 in response to the ringing tone, the hook switch 4 closes and one contact of the hook switch 15 closes. When one contact of the hook switch 15 is closed, the speaker 16
A hook signal of a predetermined voltage based on the internal resistance of is supplied to the call switching circuit 18. The call switching circuit 18 turns on the analog switch 7.12 in response to the hook signal and supplies a logic "1" signal to the power supply circuit 20.

Then, the power supply circuit 20 operates, and mutual communication between the main intercom 1 and the door phone 4o becomes possible.

In this case, the audio signal at the main intercom 1 is transmitted to the analog switch 7, the power amplifier 8. The signal is supplied to the door phone 40 via the transformer 10 or the like. Also, from the transformer 1o to the analog switch 12. Power amplifier 13. The signal is also supplied to the speaker 16 via one contact of the hook switch 15 or the like. On the other hand, the audio signal at the door phone 40 is transmitted to the secondary coil of the transformer 10, the analog switch 12. Amplifier 13. The signal is supplied to the speaker 16 via one contact of the hook switch 15 or the like.

[Problems with background technology]

By the way, if an environmental abnormality occurs during a call between the main intercom 1 and the door phone 40, an alarm signal generated by the paging/alarm sound generation circuit 3o is supplied to the communication system, and is superimposed on the audio signal to be output from the speaker of the main intercom 1. 16 and the speaker 44 of the doorbell 40. For this reason, there is a problem that an excessive alarm sound enters the user's ears, which not only makes it difficult to hear the call, but also hurts the user's ears.

(Object of the invention) This invention was made in view of the above circumstances.
The purpose of this is to provide a highly reliable security function that can issue a reliable alarm in the event of an environmental abnormality occurring during a call, without hurting the user's ears or impairing the call. The purpose of the present invention is to provide an intercom device.

(Summary of the Invention) The present invention comprises a master intercom and a slave intercom, and the master intercom includes a communication system for communicating with the slave intercom, an environment detection means, and an alarm that responds to the detection result of the environment detection means. In an intercom device with a security function, the intercom device includes a generating means and a means for supplying the alarm signal generated by the alarm generating means to the communication system, and when a call is made, the direct supply of the alarm signal to the communication system is cut off, and the alarm signal is Means is provided for supplying the signal in an attenuated state to the sounding section of the communication system.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. However, in the drawings, the same parts as in FIG. 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 1, a conventional doorbell alarm control circuit 30
A doorbell alarm control circuit 50 is provided instead. and,
The output of the environment detection circuit 27 and the voltage generated at one contact of the hook switch 15 are supplied to the door phone alarm control circuit 50 . Furthermore, an AC coupling capacitor 60 is connected in parallel to the hook switch 15.

The door phone alarm control circuit 50 has a configuration shown in FIG. 2. That is, the signal S from the environment detection circuit 27
1 is supplied to one input terminal of the AND circuit 51, and the signal S2 from the hook switch 15 is supplied to the other input terminal of the AND circuit 51 via a low-pass filter 52. Here, the low-pass filter 52 passes the hook signal from the hook switch 15, but removes the audio signal. Then, the output of the AND circuit 51 is supplied to the analog switch 34, and the output of the AND circuit 51 becomes logic 11.
0 N, the analog switch 34 is turned on, but when the output of the AND circuit 51 becomes logic "1", the analog switch 34 is turned off. Note that a DC voltage V is applied to the input side of the low-pass filter 52 via a pull-up resistor 53.

Next, the operation in the above configuration will be explained.

When an abnormality occurs in the environment, the output of the environment detection circuit 27 becomes logic It I II. Then, the calling/alarm sound generation circuit 30 generates an alarm sound signal, and the power supply circuit 2o
works. At this time, since one contact of the hook switch 15 is in an open state, no hook signal is generated, and therefore the doorbell alarm control circuit 50 turns on the analog switch 34. Thus, the alarm signal generated by the ring/alarm signal generation circuit 30 is supplied directly to the speaker 16, and is also supplied from the analog switch 34 to the door phone 40 via the power amplifier 8 and transformer 10 of the communication system. Ru. That is, the alarm sound is emitted from both the speaker 16 of the main intercom 1 and the speaker 44 of the door phone 40.

On the other hand, when the ringing switch button 43 on the door phone 4o is pressed, the voltage at the input A of the ringing/alarm sound generating circuit 30 on the master intercom 1 becomes zero level, and the ringing/alarm sound generating circuit 30 emits a ringing sound signal. This ringing tone signal is supplied to the speaker 16 via the other contact of the hook switch 15, so that the speaker 16 emits a ringing tone.

When the user picks up the handset of the main intercom 1 in response to the ringing tone, the hook switch 4 closes and one contact of the hook switch 15 closes. When one contact of the hook switch 15 is closed, the speaker 16
A hook signal of a predetermined voltage based on the internal resistance of is supplied to the call switching circuit 18. The call switching circuit 18 responds to the hook signal by turning on the analog switch 7.12 and providing a logic "'1" signal to the power supply circuit 20.

Then, the power supply circuit 2o operates, and mutual communication between the main intercom 1 and the door phone 40 becomes possible.

In this case, the audio signal at the main intercom 1 is transmitted to the analog switch 7, the power amplifier 8. The signal is supplied to the door phone 40 via the transformer 10 or the like. Further, from the transformer 10 to the analog switch 12. Power amplifier 13. The signal is also supplied to the speaker 16 via one contact of the hook switch 15 or the like. On the other hand, the audio signal at the door phone 40 is transmitted to the secondary coil of the transformer 10, the analog switch 12. Amplifier 13. The signal is supplied to the speaker 16 via one of the contacts of the hook switches 1 and 5.

By the way, during a call between the main intercom 1 and the door phone 40, the hook signal is also supplied to the door phone alarm control circuit 50, and if an environmental abnormality occurs in this state, the environment detection circuit 27 outputs a logic "1". ``The AND circuit 51 in the doorbell alarm control circuit 50 is established by the signal, and the analog switch 34 is turned off. Therefore, even if an alarm signal is generated from the paging/alarm sound generation circuit 30, it will not be supplied to the communication system. In other words, the direct supply of the alarm signal to the communication system is cut off.

The alarm signal is attenuated by the capacitor 60 and sent to the speaker 16 via one contact of the hook switch 15.
supplied to

Therefore, a low-volume alarm is emitted from the speaker 16, and a reliable alarm can be emitted without hurting the ears of the user holding the handset (and without impairing communication).

In addition, the alarm sound emitted by the speaker 16 enters the telephone line through the microphone 2, and is used as a back tone for the telephone call.
0. Therefore, a reliable warning can be issued to the user of the door phone 40 without hurting his/her ears or impairing communication.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist.

〔Effect of the invention〕

As described above, according to the present invention, when an environmental abnormality occurs during a call, a reliable alarm can be issued without hurting the user's ears or impairing the call. It is possible to provide an intercom device with a security function.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a control circuit in an embodiment of the present invention, FIG. 2 is a diagram showing a specific configuration of a doorbell alarm control circuit in the same embodiment, and FIG. 3 is a diagram showing a control circuit of a conventional device. FIG. 3 is a diagram showing the configuration. 1... Parent intercom, 4.15... Hook switch, 7, 12.34... Analog switch, 20...
- Power supply circuit, 27...Environment detection circuit, 30...Call/alarm sound generation circuit, 50...Door phone alarm control circuit,
60... Capacitor for AC coupling.

Claims (1)

[Claims] It consists of a master intercom and a slave intercom, and the master intercom includes a communication system for mutual communication with the slave intercom, an environment detection means, an alarm generation means that responds to the detection result of the environment detection means, and an alarm generation means. In the intercom device with a security function, the intercom device is provided with a means for supplying an alarm signal to the communication system, when a call is made,
cutting off the direct supply of alarm signals to the communication system;
An intercom device with a security function, comprising means for supplying the alarm signal in an attenuated state to a sounding section of the communication line.