JPH0332127Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a wireless paging device, and in particular, receives a transmitted modulated carrier wave, separates and demodulates it into a single tone signal and a voice signal, and converts it into a single tone signal and a voice signal. The present invention relates to a wireless paging device that sends a plurality of control signals formed by tone signals to an intercom main body to put it into a paging state, and then sends an audio signal to the intercom main body to generate a paging sound.

[Technical background of the invention] A wireless paging device as shown in FIG. 8 has been known. This kind of paging device 1
The device is comprised of a wireless operating device 2 as a transmitter, a receiving adapter 3 as a receiver, and an intercom main body 4. The wireless operating device 2 receives an audio signal input from a microphone 5 and amplified by an audio frequency amplifier 6, and a tone signal generated by sequentially oscillating tone signal oscillators 9, 10, 11, and 12 by a sequential scanning circuit 7. The carrier wave output from the carrier wave oscillator 13 is frequency-modulated with the signal, and the modulated carrier wave is transmitted from the transmitting antenna 14. The receiving adapter 3 includes a tuner 15, a control circuit 17, and a squelch circuit 16. The tuner 15 is the receiving antenna 1
The modulated carrier wave received at 8 is amplified by a high frequency amplifier 19, a frequency converter 20 creates a frequency (intermediate frequency) that is the difference between the local oscillation frequency of the local oscillator 21 and the modulated carrier frequency, and the intermediate frequency amplifier 22
to obtain the required selectivity and amplification gain, limiter 23 to limit the amplitude of the modulated carrier wave, and demodulator 24 to obtain the required selectivity and amplification gain.
This is to perform frequency discrimination and obtain a voice signal and a tone signal. When the modulated carrier wave becomes weak and the noise output becomes large, the squelch circuit 16 operates at the gate 2 of the control circuit 17 connected to the output of the demodulator 24.
5 is closed, and when the modulated carrier wave reaches a certain level or higher, the gate 25 is opened and the audio signal is sent to the intercom main body 4. The control circuit 17 demodulates only the tone signal out of the voice signal and tone signal output from the demodulator 24 of the tuner 15 with each demodulator of the tone decoder 26, and further switches to set the intercom main body 4 to a paging state. It is something. This intercom main body 4 emits a paging sound when an audio signal is input.

[Problems with the Background Art] However, conventional wireless paging devices require a plurality of tone signal oscillators necessary to put the intercom main body into a paging state and a sequential scanning circuit that sequentially operates the tone signal oscillators. However, there are problems in that the circuit configuration of the Ikioi wireless operating device becomes complicated.

[Purpose of the invention] This invention was created in view of the problems mentioned above.
An object of the present invention is to provide a wireless paging device whose circuit configuration is simplified by replacing a plurality of tone signal oscillators and a sequential scanning circuit constituting a wireless operating device with a single tone signal oscillator.

[Configuration of the invention] In order to achieve this object, the wireless paging device of the invention includes a transmitter that transmits a modulated carrier wave obtained by modulating a carrier wave with a voice signal and a tone signal, and a transmitter that transmits a modulated carrier wave obtained by modulating a carrier wave with a voice signal and a tone signal. A tone detector that detects only the tone signal among the signals output from the tuner that receives and demodulates the transmitted modulated carrier wave, and a plurality of controls that have a time series based on the output of the tone detector. a first gate that generates a signal, sends the control signal to the intercom main body to put the intercom main body in a paging state, and is opened and closed by a signal output from a squelch circuit connected to the tuner; A paging sound is generated by sending the audio signal output from the tuner to the intercom body only when a second gate that is opened and closed by the signal output from the tone detector is both open. It is equipped with a control circuit.

[Embodiment of the invention] A preferred embodiment of the invention will be described in detail with reference to FIG. The wireless paging device 30 of the present invention includes a wireless operating device 31 as a transmitter, a reception adapter 32 as a receiver, and an intercom main body 4. Here, the reception adapter 32 is
FM tuner 15 as tuner, squelch circuit 16, tone detector 33 and control circuit 3
It consists of 4. First, a wireless operating device 31 serves as a transmitter that transmits a modulated carrier wave obtained by modulating a carrier wave with an audio signal and a tone signal.
are the microphone 5, the audio frequency amplifier 6 connected to the output of the microphone 5, the tone signal oscillator 35, the carrier wave oscillator 13 connected to the output of the audio frequency amplifier 6 and the tone signal oscillator 35, and the output of the carrier wave oscillator 13. Buffer 47 connected to
and a transmitting antenna 14 connected to the buffer 47.
It is made up of. The FM tuner 15 includes a high frequency amplifier 19, a local oscillator 21, a frequency converter 20 connected to the outputs of the high frequency amplifier 19 and the local oscillator 21, a frequency converter 22 connected to the output of the frequency converter 20, and the intermediate frequency converter 22 connected to the output of the frequency converter 20. It is composed of an intermediate frequency amplifier 48 connected to the output of the amplifier 22, a limiter 23 connected to the output of the intermediate frequency amplifier 48, and a demodulator 24 connected to the output of the limiter 23. The squelch circuit 16 connected to the output of the intermediate frequency amplifier 22 of the FM tuner 15 includes an intermediate frequency amplifier 49, a rectifier 50 connected to the output of the intermediate frequency amplifier 49, and a switching circuit 51 connected to the output of the rectifier 50. It is made up of. A tuner 15 that receives and demodulates the modulated carrier wave transmitted from the wireless controller 31.
A tone detector 33 that detects a tone signal among the signals output from the high-pass filter 36 is connected to the output of a first gate 52 of a control circuit 34, which will be described later, and a tone demodulator connected to the output of the high-pass filter 36. 37 and a switching circuit 38 connected to the output of the tone demodulator 34. A control circuit 34 receives the output of the switching circuit 38 of the tone detector 33, forms a plurality of time-series control signals, sends the control signals to the intercom main body 4, and puts the intercom main body 4 into a paging state. are an inverter 39, a clock oscillator 40 connected to the output of the inverter 39, a timer 42, a counter 41 connected to the output of the clock oscillator 40, and switching circuits 43, 44, 45 connected to the output of the counter 41. and a switching circuit 46 connected to the output of the timer 42. The control circuit 34 also includes a first gate 52 that is opened and closed by a signal output from a squelch circuit 16 connected to the FM tuner 15, and a second gate 52 that is opened and closed by a signal output from a tone detector 33. This circuit sends the audio signal output from the FM tuner 15 to the intercom main body 4 and generates a paging sound from the intercom main body 4 only when both the gate 53 and the gate 53 are open. This first gate 52 and second gate 53
are connected in series.

The operation of the wireless paging device of the present invention constructed as described above is as follows, and will be explained with reference to FIG. First, a 78MHz carrier wave output from the carrier wave oscillator 13 of the wireless operation device 31 is frequency-modulated by a tone signal output from the tone signal oscillator 35 and an audio signal input from the microphone and amplified by the audio frequency amplifier 6. . This modulated carrier wave is transmitted from the transmitting antenna 14 to the receiving adapter 32 via the buffer 47.
The transmitted modulated carrier wave is transmitted to the receiving antenna 1.
8, is amplified by a high frequency amplifier 19, frequency converted by a frequency converter 20 from 78 MHz to an intermediate frequency of 10.7 MHz, and amplified by an intermediate frequency amplifier 22.
Here, the local oscillator 21 oscillates at a frequency higher or lower than the modulated carrier frequency by an intermediate frequency. Now, the intermediate frequency amplified modulated carrier wave is amplified again by the next stage intermediate frequency amplifier 48, the amplitude is limited to a constant value by the limiter 23, and the frequency is discriminated and demodulated by the demodulator 24. The demodulated and extracted audio signal and tone signal are output to the first analog switch 52 as the first gate of the control circuit 34. On the other hand, the modulated carrier wave output from the intermediate frequency amplifier 22 is transmitted to the intermediate frequency amplifier 49 of the squelch circuit 16.
The signal is inputted into the circuit, amplified, and rectified by a rectifier 50. Here, if the input signal voltage to the FM tuner 15 is above a certain level, the switching circuit 5
1 is switched ON to open the first analog switch 52 of the control circuit 34, which will be described later. Then, the audio signal and tone signal output from the demodulator 24 of the FM tuner 15 are output to the high-pass filter 36 of the tone detector 33 via the first analog switch 52, and the high-pass filter 36 filters out only the tone signal. pass.
This tone signal is a PLL (phase locked loop)
It is detected by the tone demodulator 37 using the tone demodulator 37, and the switching circuit 38 is turned on. The output of the switching circuit 38 then opens the second analog switch 53 as the second gate of the control circuit 34. By doing so, the voice signal and tone signal output from the demodulator 24 and passed through the first analog switch 52 also pass through the second analog switch 53 and are output to the intercom main body 4. . At the same time, the output of the switching circuit 38 is input to the inverter 39. As a result, the inverter 39
In response to the input, the reset of the counter 41 of the control circuit 34 is canceled and the clock oscillator 40 begins to oscillate. Then, the counter 41 counts the clocks and switches the switching circuits 43,
44 and 45 are made to sequentially output pulse signals. First, when a pulse signal is output from the switching circuit 43, the intercom 4 starts paging. Next, when a pulse signal is output from the switching circuit 44, the intercom block is selected. Further, when the switching circuit 45 is switched ON, the intercom main body 4 performs a paging operation, and the demodulator 24 of the FM tuner 15
An audio signal is input to the intercom main body 4 via the first analog switch 52 and the second analog switch 53, and a paging sound is generated. Furthermore, when the paging ends and the audio input to the microphone 5 of the wireless operation device 31 is interrupted, that is, when the talk switch 54 is turned off, the modulated carrier wave input to the FM tuner 15 disappears.
Since only noise is input, the switching circuit 51 of the squelch circuit 16 is turned off.
For this purpose, the first analog switch 52 is closed and the switching circuit 38 of the tone detector 33 is turned off. Accordingly, the counter 41 of the control circuit 34 is reset, the oscillation of the clock oscillator 40 is stopped, and the timer 42 is stopped.
operates, a pulse signal is sent from the switching circuit 46 to the intercom main body 4, and the intercom main body 4 performs a call termination operation.

Next, a preferred embodiment (Example 1) of a control circuit used in the wireless paging device of the present invention
will be explained with reference to FIG. The control circuit 34 includes an inverter 39, a self-excited oscillator 40 as a clock oscillator, a decimal counter 41 as a counter, two monostable multivibrators 42 as a timer, and four switching circuits 43, 4.
4, 45, and 46. Here, the inverter 39 is formed of a gate IC2. The self-excited oscillator 40 is formed by gates IC4 and IC5.
The decimal counter 41 is formed by a counter IC1. The two monostable multivibrators 42 are formed by gates IC6, IC7 and gates IC8, IC9. Switching circuit 43 is an NPN transistor
It is formed from TR1 and PNP transistor TR2. The switching circuits 44, 45, 46 are respectively
It is formed by TR3 and TR4, TR5 and TR6, TR7 and TR8. The gate IC2 has its input terminal connected to the tone detector 33 (FIG. 1), and its output terminal connected to the reset terminal of the counter IC1, the input terminals of the gate IC7 and the gate IC9, and the input terminal of the gate IC3. Gate IC3 is connected to the input end of gate IC5 and to the input end of gate IC6 via a capacitor. The output terminal of gate IC6 is connected to gate IC8 via a capacitor.
is connected to the input end of the The output terminal of gate IC5 is connected to the clock terminal of counter IC1. The Q1 terminal of counter IC1 is connected to the base terminal of transistor TR1, the Q3 terminal is connected to the base terminal of transistor TR3, and the Q5 terminal is connected to the base terminal of transistor TR5 and its own clock enable (clock
(Enable) terminal. The output terminal of gate IC8 is connected to the base terminal of transistor TR7. Furthermore, in the self-excited oscillator 40, the gate
The output terminal of IC4 is connected to the input terminal of gate IC5,
The output terminal of gate IC5 is connected to the input terminal of gate IC4 via a capacitor and a resistor, and a resistor is connected from the connection point of the capacitor and resistor to the output terminal of gate IC4. Furthermore, in the monostable multivibrator 42, the output terminal of gate IC6 is connected to the input terminal of gate IC7 via a capacitor and a resistor, and the output terminal of gate IC7 is connected to the input terminal of gate IC6, and the connection point of the capacitor and resistor is connected to the input terminal of gate IC7. A resistor is connected to the ground. Further, the monostable multivibrator 42 formed by the gate IC8 and the gate IC9 also has a circuit configuration similar to the monostable multivibrator formed by the gate IC6 and the gate IC7.

The operation of the control circuit (Embodiment 1) used in the wireless paging device of the present invention constructed as above is as follows, and will be explained with reference to FIGS. 2 and 3. First, the tone detector 33 (Fig. 1)
When the switching circuit 38 (Fig. 1) is turned on, the gate of the control circuit 34 is turned on.
The output terminal of IC2 changes from H level to L level, and counter IC1 is reset. gate at the same time
The output terminal of IC3 becomes H level and the self-excited oscillator 40 starts to oscillate, and a clock is applied to the clock terminal of the counter IC1. Then, the Q1 terminal of counter IC1,
Transistor TR1,
Pulse signals are sequentially output to TR3 and TR5. As a result, time-series pulse signals appear at the output terminals of the receiving transistors TR2, TR4, and TR6.
However, in this case, since the Q5 terminal of counter IC1 is also connected to its own clock enable terminal, counter IC1 stops its counter operation.
Therefore, an H level signal is always applied to the output terminal of the transistor TR6, and is maintained while the paging sound is being generated. Next, when the switching circuit 38 (FIG. 1) of the tone detector 33 (FIG. 1) is turned off, the output terminal of the gate IC2 of the control circuit 34 goes from L level to H level, and counter IC1 is reset. At the same time, the output terminal of the gate IC3 becomes L level, and the oscillation of the self-excited oscillator 40 stops. And 2
The two monostable multivibrators 42 operate and send pulse signals to the switching circuit 46. Then, a pulse signal appears at the output terminal of the transistor TR8, and the intercom main body 4 (FIG. 1) is operated to terminate the call.

Next, another embodiment (Embodiment 2) of the control circuit used in the wireless paging device of the present invention will be described with reference to FIGS. 4 and 5. Inverter 3
9. Self-excited oscillator 40, monostable multivibrator 42, switching circuit 43, 44, 45, 46
has the same circuit configuration as in the first embodiment, but the counter 41 has a different circuit configuration. That is, this circuit uses five delay type flip-flops (hereinafter referred to as D flip-flops) IC11, IC12, IC13, IC14, and IC15 instead of a decimal counter, and inputs the outputs of the respective D flip-flops.
Input NOR Gate (NOR Gate) IC17, IC18,
Consists of IC19 and IC20. When all D flip-flops are reset,
Due to the 5-input NOR gate, only the _D0 input of the first D flip-flop IC11 is at H level.
For this purpose, when a clock is input from the self-excited oscillator 40, the outputs of the D flip-flops are sequentially sent to switching circuits 43, 44, and 45. In this case, when the output is sent from the D flip-flop IC15, the gate IC10 is closed, so that the clock is no longer applied to the counter 41. By configuring the control circuit 34 in this manner, the same operation as in the first embodiment can be realized.

Further, another embodiment (Embodiment 3) of the control circuit used in the wireless paging device of the present invention will be described with reference to FIGS. 6 and 7. Monostable multivibrator 42 and switching circuit 43, 4
4, 45, and 46 have the same circuit configuration as in the first embodiment, but the counter 41 has a different circuit configuration, and the self-excited oscillator is also not used.
That is, this circuit uses four monostable multivibrators and one RS flip-flop instead of a counter and a self-excited oscillator. Each monostable multivibrator 41 sequentially turns on the switching circuits 43 and 44, and during paging,
The switching circuit 45 is switched by keeping the RS flip-flops IC31 and IC32 in one state.
Keep it ON. By configuring the control circuit 34 in this manner, the same operation as in the first and second embodiments can be realized.

[Effects of the Invention] As is clear from the above embodiments, according to the wireless paging device of the present invention, the transmitter transmits a modulated carrier wave modulated with a voice signal and a tone signal, and the tuner transmits the modulated carrier wave. The carrier wave is demodulated, and a tone detection circuit detects only the tone signal among the obtained signals, and a control circuit receiving the output of the tone detection circuit forms a plurality of time-series control signals to generate an intercom. Since the system is configured to put the tuner in a paging state and send the audio signal output from the tuner to the intercom to generate a paging sound from the intercom, the circuit configuration can be simplified compared to conventional wireless paging devices.
Accordingly, there is an effect that manufacturing costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a wireless paging device according to the present invention, FIG. 2 is a circuit diagram of a control circuit (Embodiment 1) of a wireless paging device according to the present invention,
FIG. 3 is a time chart showing the operation of the control circuit for the wireless paging device according to the present invention (Embodiment 1), FIG. 4 is a circuit diagram of the control circuit for the wireless paging device according to the present invention (Example 2), and FIG. 5 6 is a time chart showing the operation of the control circuit of the wireless paging device according to the present invention (Embodiment 2), FIG. 6 is a circuit diagram of the control circuit of the wireless paging device according to the present invention (Example 3), and FIG.
The figure is a time chart showing the operation of the control circuit (Embodiment 3) of the wireless paging device according to the present invention, and FIG. 8 is a block diagram of the conventional wireless paging device. 4... Intercom body, 15... FM tuner, 16... squelch circuit, 30...
...Wireless paging device, 31...Wireless operation device (transmitter), 33...Tone detector, 34...
Control circuit, 52... first analog switch (first gate), 53... second analog switch (second gate).

Claims (1)

[Scope of utility model registration request] A tone signal is output from a transmitter that transmits a modulated carrier wave obtained by modulating a carrier wave with an audio signal and a tone signal, and a tuner that receives and demodulates the modulated carrier wave transmitted from the transmitter. A tone detector that detects only the signal; and a plurality of time-series control signals formed by receiving the output of the tone detector, and transmitting the control signals to the intercom body to put the intercom body in a paging state. At the same time, a first gate that is opened and closed by a signal output from a squelch circuit connected to the tuner and a second gate that is opened and closed by a signal output from the tone detector are both connected to the tuner. 1. A wireless paging device comprising: a control circuit that causes an audio signal output from the tuner to be sent to the intercom main body to generate a paging sound only when the tuner is open.