JPS5940342B2 - intercom device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intercom device having a plurality of handsets (terminals), in which the called handset automatically selects a station, generates a ring tone, and can make a call. The purpose is to

Conventionally, when the parent-child intercom device has a single communication circuit on the base unit and only requires a response, and the base unit has a loudspeaker type that does not allow the base unit to distinguish between when the handset is talking and when it is not talking. If you do not make sure to disconnect the handset and the base unit when you are not talking, the voice will be emitted to the handsets that do not need to talk.

Therefore, it is necessary to perform a channel selection operation on the called handset before making a call. Therefore, in such a conventional device, when the number of slave units increases, the operating portion becomes large and the base unit also becomes large. The present invention seeks to eliminate the above-mentioned drawbacks, and examples thereof will be described below.
FIG. 1 shows an example of a parent-child type intercom device having a plurality of handsets, where 1 is a calling and talking section of the base device, 2 is an automatic channel selection circuit, and 3 to n are handsets. FIG. 2 shows the respective circuits of slave units 3 to 6. Next, the operation will be explained.

FIG. 1 shows a connection between the oscillation circuit OSC of the base unit 1 and the first slave unit 3 from the contact a of the hook switch 51 for switching calls on the base unit to the contact of the switching circuit RS4 of the latching relay RYA of the tuning circuit 2. A state in which the terminals are connected in a loop of →terminal ILI→first slave device 3→terminal 1L2→common line C is shown. Here, when the first handset 3 closes the calling switch 52, a switching circuit consisting of transistors T4, T2, resistors R4, R2, R3, R4, R5, and capacitors C1, C2 passes through the hybrid coil HYB) terminal IL4. to drive. That is, the transistor T2, which is in the ON state from the power supply E through the resistors R3 and R4, is connected to the first slave unit 3.
Since the call switch 51 is closed, the base bias is turned off and the collector potential rises. and resistance R
In order to charge the capacitor C1 through 2 and supply current to the resistor R1 and the base of the transistor T, the transistor T is turned on for a period of approximately τ■C4×R4, and current flows through the winding CLI on one side of the latching relay RYA. At this time, the contact Rs4 has already been switched to the γ1 side, so the state of the circuit does not change at all. At the same time, the oscillation circuit OSC of the base unit 1 is driven through the loop with the base unit 1 described above to notify that there is a call from any of the slave units 3 to n.

Next, when the second handset 4 closes the call switch, the transistors T3, T4, resistors R6 to R40) capacitor C3
, C4 operates in the same manner, but in this case, the diode matrix circuits D2 and D3 switch the second winding DL2 of the first latching relay RYA and the first winding CL3 of the second latching relay RYB. At the same time, connect the first switching point Rs to the R2 side and the second switching contact RS2 to the γ3 side to connect the second slave unit 4 and the base unit 1, and then do the same in the same way. The oscillation circuit of base unit 1 is driven to notify that a call has been received. Similarly, when the third handset closes the call switch, transistors T5, T6, resistors R]]~Rl, capacitors C5, C
By driving the switching circuit composed of 6 and the diode matrix circuits D4, D5, and D6, the second windings CL2 and C of the first and second latching relays are respectively driven.
L4 and the first winding CL5 of the third latching relay are simultaneously driven to switch the eleventh second and third switching contacts RSL.
, RS2, and RS3 are connected to R2, γ4, and γ5, respectively, to connect the third slave unit and the base unit 1. In other words, one latching relay is used for the purpose of distinguishing two slave units, and when a slave unit with a certain number closes the call switch, all the latching relays placed in front of it close the second winding, and immediately after that, One latching relay installed connects the slave unit and the base unit by driving the first winding with a diode matrix, and also connects the oscillation circuit of the base unit 1 through the connected loop. 0SC is driven, and then when base unit 1 responds, switch S is switched and connected to contact b, so that a call can be made via call circuit T. Note that the diode D1,
and this diode D, connected from. connected resistor R5,R
, O, R, 5, . . . are used to prevent malfunctions such as switching and interrupting the call in the event that base unit 1 answers and a call is received from another handset during a call. A part of the direct current for communication supplied from the communication circuit T is given to the switching circuit as a bias current. In addition, capacitors C2, C4, C6, ...... are connected to the base unit 1 when calling.
This is a capacitor that bypasses AC signals such as back tone signals that are sent backwards.

As is clear from the above embodiments, according to the present invention, a connection is automatically established between a called terminal device and a base unit, and the operation is extremely easy. Furthermore, even if there are a large number of terminal devices, there is no risk of increasing the size of the device since the number of electric circuits will only increase.

[Brief explanation of drawings]

FIG. 1 is a wiring diagram of an intercom device according to an embodiment of the present invention, and FIG. 2 is a wiring diagram showing detailed purchasing of main parts. 1... Calling section of the base unit, 2... Immediate channel selection circuit, 3~n... Child unit, T1~T7...
...Transistor, D2-D8...Diode, RYA-RYO-F...Latching relay,
Rs, ~Rs4...Contact.

Claims (1)

[Claims] 1 A plurality of handsets, switching circuits provided corresponding to each of these handsets and operating respectively when a call is received from the handset, and a first winding on the output side of each of these switching circuits. The latching relays are connected to each other, and the second windings are connected to the output side of the subsequent switching circuit, respectively, and these latching relays are driven, one fixed contact is connected to the slave device, and the other fixed contact is connected to the slave device. An intercom device comprising contacts of the latching relay each connected to a movable contact at a subsequent stage, and configured to connect an upper machine and a base unit to each other via the respective contacts of the latching relay.